I know this is outside what we usually talk about but it's something for me to do while waiting for Mini engine parts to arrive, and it's helping me make yet another connection for both new work and parts.....so......yay! ;D
The customer actually sent me three complete gearboxes with orders to make one good one, one of the gearboxes turns freely, the other two do not. The free one was recently worked on by someone who admits that he knows nothing about working on gearboxes - cars either I'd bet, based on what I'm seeing.......which is parts missing (like detents that keep the box from going into two gears at once - fairly critical) and parts not installed correctly, old gaskets reused, bearings missing shims and the wrong gearoil in the box (these use 30 wt motor oil, he had 90 EP gear oil in it....)
So, this is what I started with....on teardown it didn't look too bad. Everything was pretty clean inside at least......
First thing I did after stripping the case was take them up to school and use the bead blaster.....they're not perfect but about a million per cent better than they were.....the customer was suitably impressed when I sent him this pic!
Next came inspection of the gears themselves, most are in pretty good shape. There is some wear on the 1st gear, but as this box is not synchro'd on first that's to be expected.
I did see some damage to the coating on the synchro areas of a couple of the gears but I think this is still serviceable.
I bought an "overhaul kit" from Victoria British for about $150 which includes all the paper gaskets nd oil seals, a new layshaft and it's roller bearings, new synchro balk rings, new mainshaft bearings and the idler bearing.
However, I now have an issue to resolve - as the previous guy clearly did not know what he was doing...... the replacement mainshaft bearings are .625 or so thick, the OE bearings were .720, so they provide shims. The previous guy replaced the bearings but did not use the shims, and as I don't trust his workmanship I have to figure out what shims to use and where they go....still working on that......
The last pic shows there were no shims behind the main bearing......
Next installment, I'll disassemble the entire mainshaft cluster, replace the rear main bearing and synchros and check to make sure all the detent balls and springs are present and in the right places.
I shall watch this with great interest never been inside a gearbox in my life.
They're not all that difficult, but there are some "tricks" you need to know...like the hubs on 3-4th gears have three detent balls in them, I can hold two but don't have enough hands to hold three and slide the hub over the detents, the answer is a hose clamp to hold them in place, then just tap the hub on.....
There also is a distinct sequence to both disassembly and reassembly, get it wrong and either you take it apart again or something gets stuck......
Reinstalling the layshaft and gear is kinda "fun"....those two bushings have to go in with the gear, which lays at the bottom of the box to provide room to get the mainshaft gears in place, then you raise the laygear into place and slide the layshaft in without losing the two bushings on either end!
How does he do it you say?
Simple, I cut the old layshaft off slightly so it's the exact length of the laygear and bushings, put it all together and drop it in place. When ready to install I shove the old layshaft out by pushing the new one in.....
(http://www.restorationmini.com/forum/index.php?action=dlattach;topic=1044.0;attach=4886;image)
I had to take a day away from the gearbox build to work at one of my other jobs and then another day to handle some things at school before the fall semester starts.
With that out of the way I got a little more done on the gearbox tonight, I changed out both main bearings and disassembled the rest of the main shaft...the synchros were absolutely toast! Worn down to nothing, I don't know how they even shifted gears with them so worn. I put the new synchros in and assembled the shaft, but once together I realized that whoever worked on it before left out the detents that hold the 1st/2nd gear sliding sleeve in place so I get to take it back apart again and make a trip up to Vicky Brits to get some detent balls and springs. The rear main bearing was not seated in it's housing properly either
The kit came with a new layshaft and needle bearings and I see why they recommend changing it anytime you strip one of these down - it had heavy wear in the shaft.
So tomorrow, I finish cleaning the cases - the one downside of using a bead blaster is that bits of the glass embed themselves in the aluminum and you really have to scrub it to get them all out. Then I can go ahead and put it all back together.
Another day in the shop......I now have the mainshaft all assembled and ready to go back in the case, it did involve 2 trips up to Victoria British tho, when my neighbor buddy came over and said "what's this" as he slid the 1st gear operating sleeve off the hub and sent three tiny detent balls and springs flying everywhere! This was my second trip up there as in the am I found it had no detents at all, so I went and bought a set. We found 2, so I had to drive up again, this time I bought all they had in stock - 5 detent balls and three springs.......
So that's all done.....
I also replaced the caged needle bearings in the laygear, changed out all the synchros, shimmed the bearings correctly and tightened all the locknuts and bent over the locktabs.
Today I cleaned the cases up, tapped all the threaded holes, cleaned the threads on all the studs and got everything ready to re-assemble. One of the downsides of using the bead blaster is that tiny glass detritus gets everywhere, every threaded hole, every passage everything has to be wire brushed and blown out repeatedly......the cases look great but it's a lot of work!
Things were going so well, I was figuring out the right sequence of reassembly, I had the laygear in place, reverse gear in place next up was to insert the first motion shaft, when this happened......
The gears have a coating where the synchro rides (Mini gearboxes do also, so it must be a BMC thing) that sometimes chips or fails. This one had some chips in it but they didn't look fatal, but as I was pushing the 1st motion shaft into place in the case a big chunk of the coating came off. There is no way to fix it, and these parts are rare!
You used to be able to buy the coatings, they are some sort of compressed metallic fibrous stuff, you heat it to 250*F then slip it over the gear and immediately quench it, then you have to grind it to the right profile - none of that is done today and the cones are NLA, along with the gearshaft. MiniMania had one, they wanted $400 for it but I found a used one for $100 on Ebay, then I got lucky and found a NOS one for the same price - it's wending it's way to me now from Ca.
Till then, I'm stopped on this job.......it may get here on Sat. Too bad, I would have had it all done by tonight.....
In the first pic you can see where it was chipped - the synchro doesn't ride there so it didn't matter much, till the big chunk just fell off. Now all its good for is as a clutch alignment tool......
Cool project Dave Thanks for posting.
Very similar to the early mini box where the friction material is on the gear rather than the ring not a very serviceable design this type use steel syncro rings. Looked like their may have been a brass one mixed in the pic you took it might just be the coloring and im sure you all ready know that but you don't want brass rings in that trans.
A couple ways I have fixed those is to keep the steel sync ring and press a silcone bronze ring on in place of the broken mystery friction material and then turn to final size and taper works fine as good as the stuff that broke off. Or press a 4140 steel ring on in place of the friction and switch to a brass syncro ring they are the same size, this is the better choice because then the wear item becomes the easily replaceable syncro ring.
Sometimes the steel rings end up in the later trans that has a steel gear hub and of course they don't work I have fixed two that had that problem where the car owner got the cheapest stuff he could find and ended up one or two steel syncro's in a later trans.
The early three sync mini used a silcone bronze friction against the opposing steel gear they are also nla I made two of mine and shrunk them on and turned to final size.
It works great I used aluminum bronze and it works well but silcone bronze is what most factory syncro's are made from.
You have this one worked out but thought I add this for future projects or readers they can be repaired if you have or want to.
Here's one of my mini syncro's that I redid.
Hang on, let me make sure I understand you - brass on the hub with a steel synchro is OK, right?
Because I think the NOS shaft I bought has brass on the gear as the friction material........
Maybe I could send this old gear off to you for a refurb? Other than the synchro surface it was in great shape.
You're good to go if the gear has brass you want a steel synchro. And thats what that trans should of had.
I would be happy to refurb one for you or anybody if needed I would use a brass material just like the nos one you bought or steel and you would then have to get a brass synchro up to you. If you ever have me do one I need a good synchro with it to get the fit right.
Jeff
Cool, I may have two more of these gearboxes to do for the guy, we'll see what he says after I finish this one. The synchros are definitely steel.
It's great having access to machinery like you do, I'm glad I have what I do at school - we have lathes and mills and such there too but as I'm not an instructor in that dept I'm not allowed to use them - so I just get access to the car shop equipment..
Times have changed I seem to remember other teachers using whatever they wanted with permission and a quick safety test. But that was 20 years ago, damn i'm getting older. I even took a class in high school where we did metal casting bet those are gone.
If you were near you could come use my stuff anytime but I can sure do them if you end up needing. I have a fair amount of aluminium bronze left from other transmission projects.
Jeff
I think the only metal casting done in our school is in the art/sculpture dept! ;D
We'll see what happens once I get this one built, I haven't taken either of the other two apart, he says both are "locked up", I've never seen a gearbox locked up from rust like an engine unless it's been stored under water or open, and both of these are oily, dirty and complete enough that's not the case, so I'm guessing jostled around enough that somehow they've dropped into two gears or something.
I bought a roll of butcher paper to cover the lift table surface, this keeps things cleaner and makes it easier to find that odd bit I might have misplaced.
The new shaft should be here Sat, hope it's the right one.....if not I'll be sending this old one off to Jeff to work his magic on it!
The last pic is of the other two gearboxes waiting their turn....
Well, the new first motion shaft turned up today, a few days early but unfortunately it's not the right one for this car. However, the good news is he has a Bugeye Sprite with the smoothcase gearbox that has grunchy gears and needs overhauling too, and guess what this one fits?
So no loss at least.....but now I'm back trying to find a solution for this one and possible the other two if their synchros are in the same shape....that's just cardboard dust and cosmoline on the new one.....
Had a great conversation with Jeff10049 and we think we have a way to fix this gear, so I'll box it up and get it on the way to him and hopefully he'll have some pics to add sometime in the next week or two. Thanks Jeff!
It's here.
Started with some measurements. Then removed the rest of the friction material and polished up the surface.
It is hardened enough to run a bronze synchro on it. So I decided to see if one of the used steel synchros would cut ok on the lathe, it did very soft steel.
So it was bored out and will get a c954 aluminium bronze insert bored to correct taper to run on the gear hub.
Started at the business on the old atlas lathe then got home dug out the aluminium bronze and enlisted the ole sawmaster power hack saw to cut off a chunk for machining.
I have fallen behind on this thread due to vacation and being behind at work.
Just caught up with this thread (still behind at work) and wanted to say it is a blast to read. Kudo's to Jeff for jumping in to do some fab work.
Dave, your knowledge and Jeffs as well is really amazing. I am reading with great interest.
Carry on. ;D
Thanks Jim, we both had the ideas, but Jeff has the skillz and equipment to make it happen!
Jeff, how much did you take out of the synchro, and how thick will the insert be?
After talking with some Sprite gearbox guys in the UK, come to find out the surface that was damaged on my gear is some sprayed on metallic stuff, not replicatable now (at least cost effectively) so Jeff's idea may be the only way to fix these in the future. There may be a few of these gears NOS somewhere, but I sure couldn't find one and the UK gearbox guys say all they have are used ones.
cut the synchro straight took .100 out of synchro thick side about 20 out on thin side that minus the thickness of the coating will make the insert about .125 on the thick side and about .050 on the thin with about .030 remaining at oil the groves on the thin side. And .068 remaining on the steel ring.
It's interesting you found out about the spray coating I was thinking about a spray welding of some kind as it looked spray welded to me. Something like A Molybdenum alloyed cast repair spray could maybe work I do have the equipment to do that, but i'll leave that for another day figuring out a suitable coating will take some digging then it still may not work.
I did save a chunk of coating at some point I will have it XRF tested to see what it is just for fun.
working on the jet 12x36 lathe at home today got the aluminium bronze roughed out at the shop in between stuff yesterday. chucked it up here and finish turned the od for a .003 interference fit into the old synchro. heated up the steel part and coated the bronze with locktite and tapped them together. I ended up just using the new steel one you sent as I could not get oil to stop coming out of the used one when heated that was also affecting the surface finish when machining.
Next I swept the taper of the shaft with a indicator to find it was a 9 degree taper. set the compound chucked up the bronze lined synchro and cut the taper to size. Then the round grooves. Next a parting blade on its side was used to manually cut the oil relief slots buy cranking the carriage in and out.
It fits well even sticks on there you can pick the shaft up buy the ring so the tapers match well. IT feels like it should have plenty on braking force when turing by hand.
more pics, Also if you would Dave check the height of a good sync and hub this one has lots maybe too much I imagine it'll wear somewhat quickly at first I just don't want it binding up I don't know how much wiggle room their is I can always take one more light pass.
Wow, that looks fantastic!
I think we'll try it as it is, I should have sent you an extra new synchro to compare, I can get them easily up at Victoria British, just a few miles from my house. I think we did this repair exactly the right way....
Thanks you so much for taking this challenge on, you did a great job!
Thanks Dave,
A extra new would not really help a good coated hub and new sync would be needed. I did measure the new one you sent on the hub before starting any work. It's about .005 more gap but i'm sure the old coating had some wear and of course the flaked off section so I think were good. I sure don't want to take off to much as i'd have to start all over.
I did not need to remove the bearing you may want to spray it out with brake cleaner just to be safe but I taped it off when removing the rest of the coating, and polishing the taper. I did not remove the nut either so if it was torqued it still is.
I'll ship it back your way Monday.
Dropped off at ups on way home Pm'd tracking number you should see it this week.
Alrighty then, gear showed up today, so tomorrow I'll see about putting it all back together......
cool, Will the owner be putting it in the car right away? I'm interested to see how it all works out. I did quite a bit of math on area and friction coefficient to come up with the oil relief groove width and number on both the slots and circular grooves. A balance between getting the oil out fast and having enough contact area for friction. I noticed the old steel synchro you sent they were a softer metal had larger/wider and more grooves than the newer harder synchro. Something that seems so simple yet has so much going on.
I don't think it will be right away, he bought an engine but got it home and found it had no compression, so I think he's still working on sorting that out - he only paid $800 for the car so he doesn't want to spend $5K rebuilding the motor. I'm staying under $500 on the trans build.
I'm trying to figure out how I could hook up an electric motor to turn the input shaft (slowly) so I could bench shift it, I also want to see how/if it works, but I have a very high degree of confidence in your work!
I should have it back together tonight.
Ran into an issue....there are several different detents, balls, plungers, springs etc for the shift rods and since this gearbox has been apart I did not know what went where, so since I have two more gearboxes I thought I'd simply look at them. Some of the detents are held in place with threaded plugs so I removed both of them on one of the extra gearboxes and made note of what went where.
Then I did the same on the second gearbox - they were assembled completely different!
So, I emailed a friend in the UK who used to build these for a living and asked for some guidance. One thing's for sure, by the time I finish this one I'll be able to do them in my sleep!
Hooking up a motor would be kind of fun I know it will work how balanced compared to other shifts it is and will it ever give a crunch under certain conditions is what I'm wondering, of course even stock ones can do that if way mismatched shifts are forced.
Same material I used in my mini on second gear much more demanding than fourth and it's perfect but a lot of engineering goes into stuff like this so a guy whipping out a weekend synchro is not a 100% sure thing.
How about a piece of heater hose between a 1750 rpm motor shaft and the input with some clamps?
Did you save the dc motor and speed controller out of that junk treadmill you built the engine stand out of? that could be a cool use for it trans tester motor.
Jeff
No, but I gave it to my neighbor across the street, he may still have it - that's a great idea!
I got it mostly assembled today but I'll need to take it apart again and re-shim the bearings, there's too much clearance between the main shaft and first motion shaft.....
My friend in England (who's the Sprite gearbox expert) contacted me back so I got all the detents and plungers sorted out, I sent him pics of what you did and he said he'd seen it done on other gearboxes in Germany and he thinks it will work just fine.
wow that's cool, not that I thought I was the only one that ever did it but you sure can't find much info on the net about fixing/making a synchro. Material choices are hard to find as well. I have a folder on the computer full of info about it but it took a lot of searching to find it.
I also bought several books but whats scary is some of the books that are considered the end all do all have bad info, they were not written by someone who has done it.
But by some technical person sitting at a desk with a part and measuring tools that interviewed some engineers on the subject and formed their own idea.
The encyclopedia of automotive engineering has some very incorrect info on the subject a $2000,00 book. If you were to try and build a synchronizer ring from info in that book you would fail.
There is way more incorrect/bad info on the net about synchronizers than good. Some of the u tube videos about how they work are painful to watch they are so full of bs.
I should create a page about the ones I have repaired materials used and the end result that the search engines can find. Also with links to the info I have found that is good and correct about the operation.
A video of a transmission driven by a motor with the top off and just using a fork to shit would be cool wish I had a high speed camera to show the operation of the ring.
For those reading that may not know what a synchro does it's just a cone clutch. When the slider starts to move the dogs in it contact the synchro first and push it onto the cone of the next gear at this point in time the ramp portion of the teeth in the slider and synchro should be touching and the gears are traveling at different speeds.
This speed differential keeps the synchro loaded against the slider teeth the harder you push the more force you put on the cone clutch to either speed up or slow down the input shaft to match the road speed. This also puts more force on the ramp areas of the teeth that are in contact to keep you from pushing past and grinding the gears. since they are ramps they try and force apart.
Sometimes they are called blocker rings instead of synchros because they block the
shift. Once the the input and output speeds are synchronized their is no force against the ring and it allows the teeth to slide past and on to the mating gear with out a crunch. The closer the driver matches the road speed to engine speed the easier life will be on the synchro. The reason why tapping the throttle on a downshift makes it quicker you're helping the synchro get the input up to matched speed.
they're are many different types 2 piece up to 6 piece synchronizers but they all work the same sometimes they move the gear hub instead of having a ring and the friction material is on the gear like the gear dave got on ebay that style uses the least moving parts.
Hears a link to some pictures of how the teeth meet up if anybody cares. They're a little full of themselves as we are a shop that has been doing what they do for years we used to have to adjust the timing of synchros on the mitsu 5 speed truck trannys in d50 pick ups back when I was starting out at 16 years old they had a problem where the teeth points would meet up and lock you out of a shift. But they're right in that you don't hear about it. Most shops just fix stuff and the owner hears blah blah blah here's your bill. They do sound like they know their stuff though.
http://www.jackstransmissions.com/pages/synchro-blueprinting
Jeff
Interesting article.....so it looks like what they do is narrow the teeth slightly so as to sharpen the engagement points and make it easier for the teeth to slide past each other into engagement?
The other synchro type I'm familiar with are the Porsche style...they work almost like a centrifugal clutch. Two small bands and a couple of bits, as you move the slider towards the gears it engages the bits which force the bands against the hub, causing the speeds to match and allowing the slider to engage.
Here's what they look like....
(http://www.datsunroadster.com/images/PARTS_NEW_PICS_NEW4UP/servo_synchro_parts.jpg)
We used to replace these by the box load as truck drivers would ruin them getting them on and off the transporters....I don't know how.
Great stuff Jeff, and thanks for you close attention to my project, I appreciate it!
Those porsche ones work really good I wonder how the heck they were ruining them maybe a bad batch and that was the excuse?
I had a car that the synchros had no blocking action they were just a synchro the preload dogs was all it had so you had to shift it gently the cone would come up and start to synchronize but if you pushed past the tension of the dogs too soon it would just grind. Thats how it was made you just had to know how to drive it and it worked fine sort of a feel thing come up against it and wait until it felt like no more tension and follow through. 1968 lloyd wagon maybe, or it was the 1960 model 96 bull nose two stroke three cylinder saab I can't remember but it was one of those cars. The 2 stroke saab was fun I'd be poring a quart of oil in the gas tank at the station and get looks like WTF I'd just say it's a quart low they would shake their heads and walk off muttering dumb ass kid LOL. That car had some power when you wound it up.
Probably the Lloyd, I owned a few of those 2 stroke Saab stories and I remember being able to shift as fast as you wanted.....
I think I have all the mysteries sorted finally, know where all the detents go, and had the main and first motion shafts installed but took it back out again. There was what I considered way too much play in the 3-4 shift sleeve (even tho my contact in England said it was fine that way) so I shimmed behind the bearing on the first motion shaft, doing so moved the gear into better alignment with the layshaft gear too....so now I'm putting it back together again, hopefully for the last time.
In the first pic you can see the misalignment - although the angle of the photo makes it look worse than it was, it's the gear on the right end - in the second pic the gear fits nicely into the layshaft gear. You can also see the increased gap between the gear and the bearing - I used every shim I had hoping it would be enough and I think it was just right. This should take out a lot of the play too, but if you take out too much the cones won't release and it won't shift. All the other gears line up with the layshaft perfectly so I decided not to change the shims on the rear bearing. When I measured one of the other gearboxes the play was about 1/8", this one was more like 1/4"....this is what you get when someone who doesn't know their way around the shop starts "tinkering".....by the time I'm done with this one I'll be able to rebuild them in my sleep! ;D
After all this I sure hope it works, although it may be a bit before I get to find out - the engine he bought that went with this transmission had no compression - we don't know if somethings wrong or if the PO was tinkering with it too. By the time I'm done I think he'll have that sorted too but I may wind up going thru the motor also - just enough to make it run. I'm hoping the PO got the valve adjustment wrong or something simple like that, I don't think anyone's been inside the motor based on the oil/dirt on it.
The car he bought is a 68 Sprite Mk II, and it's hard to believe but it has no rust - none! He paid $800 for it so he's not looking to spend $5K on a motor and trans for it....I'm bound to a $500 max on the gearbox build and it will take all of it....but thanks to Jeff10049 at least I'll be able to save it.
When I look at gears it might as well be Chinese. Glad you know what you're doing!
No one ever said I know what I'm doing! ;D ;D ;D ;D
Well, it's coming together......there are some shims that go on the rear bearing and they look like wave washers instead of being nice and flat.....consequently I couldn't get them to hold still so I could install the back housing. So I sprayed some high tack on them and weighed them down with a big impact socket. If they flatten out all I have to do is put the rear housing on and install the shift housing and shifter and it's ready to go.
It took a while to get back on top of all the little bits and bobs, but I have it all sorted now. Ken Evans at Klassic Transmissions in England was a great help, we must have emailed back and forth 4 times........
cool,
I would of moved the input in as well, and I keep forgetting to say that I use walnut shells in my blast cabinet for stuff like this way easier to clean and more forgiving if you miss some. Baking soda works well also just wash it away great for old electrical contacts too. glass bead is a bitch to clean out as you know.
I have a walnut shell pressure blaster that I built to clean the carbon off the intake ports and valves on my MINI, direct injected cars are afflicted with carbon buildup - I will use it next time, for sure!
Glass bead might give a beautiful finish, but man what a PITA to clean up afterwards!
Allrighty then.......tonight I buttoned up the gearbox, all the gears engage and shift smoothly, and the shafts turn easily as they should. Of course it looked better before all my oily pawprints were all over it......oh well.......
I managed to get the second gearbox out of the two gears - it was locked in 4th and reverse and it feels pretty good now. I think it could easily be rebuilt. The third gearbox has noisy bearings but I think it can be saved too......
Customer came and picked up the first gearbox today.......and dropped off yet another one for me! I'm also going to pick up the no-compression engine and see if I can figure out what's bothering it too.
He also has a Bugeye gearbox (smooth case) he wants me to fix, as it grunches pretty good into second.....but it's still in the car..... tomorrow when I pick up the engine he wants me to drive the Bugeye to see what it does before he pulls it out.
By now I think I pretty much have the hang of these!
The one I finished is going to be a spare for his Bugeye so I may never know if the work Jeff did on the synchro works unless he decides to use it while I have the smooth case out for overhaul. I doubt he'll do that tho as it's quite a lot of work to get these in and out. The second one will go in the 68 Sprite (assuming we get an engine that runs) and the other two - who knows, maybe he'll sell them. The main thing is his money is good and he's bringing me more work. 4.gif
Next thing you know you're buying a shop in Ramona and building engines and gearboxes full time ;D
It is an engine and trans out to get the trans out of a bugeye. Enclosed under it so no other way.
Yep, that's why I don't think he'll want to install this one then change it back to the smooth case once it's rebuilt.
Quote from: 94touring on August 20, 2016, 01:17:06 PM
Next thing you know you're buying a shop in Ramona and building engines and gearboxes full time ;D
Yeah, what do you think the chances are of me finding a cool little shop like yours, for affordable money?
Second, what do you think the chances are that my bride will want to live there?
bummer seems like a lot of work for a spare I hope he uses it I want to know how well it all worked out.
Yeah, I thought he might put it in the Bugeye while I rebuilt that one.....if I can get the engine for the '68 running he may put it in that one........that's the car I thought I was building it for.
Who knows???
Working on gearbox #2, I decided not to bead blast this one but just took it apart and cleaned it in the solvent tank - no question bead blasting them looks great but it's such a mess to clean up.
This one was in considerably better shape than the first one, all it took was the overhaul kit which has new bearings, laygear shaft and bearings, seals and gaskets and synchros. This one also had been apart before and I found one detent ball missing and an incorrect spring behind one of the shift locating plungers. I also found the pin that holds the reverse gear shaft in place was bent - I have no idea how they did that but I was able to straighten it again and save it - as those are NLA parts.
When I got it it was locked in two gears and the shift linkage was bound up, once I got it apart I found the missing detent ball and I think that's how it got into two gears at once. Overall the first and reverse gears are not as banged up on this one and once finished I would use this one over the 1st one I built for him. I still have two more gearboxes to build for this guy if he goes ahead with them.......
I'll finish it up this afternoon, then I need to start work on my green Mini, we have a driving event coming up and there are lots of little things I want to do before I hit the road.
All done and ready to go home.....
That one went together lots faster than the last one!
Nah, I just posted the pics together.....but you're right, once you've done a few it's less of a mystery. Each one presents it's own little issues tho.
Of course, I didn't have to send a part off to Jeff to b re-engineered too!
Great thread! I am looking to rebuild my ribcase trany very soon, and this is very helpful. Looks quite similar to a Mini trany, but easier to get to and no drop gears ha ha.
Now to read over the manual before disassembly.
p.s. Ever hear of installing the trany and motor separately being an easier go of it?
Quote from: pbraun on January 31, 2017, 02:22:20 PM
p.s. Ever hear of installing the trany and motor separately being an easier go of it?
On Sprites/Midgets the tunnel area is enclosed on the bottom. It has to go back in as engine/trans unit.
You have to pull the motor to get the trans out, just like on my E-Type.....
There are only a few "gotchas' on the Sprite box, make sure you get all the inter-shift rail plungers back in, and in the right place, and the sequence of installation is important - follow the book for sure.
Other than that, not too bad....the thrust washers for the layshaft can be a bit fiddly too....
Victoria British sells a kit with all new bearings, layshaft, synchros and gaskets/seals that has pretty much everything you need in one kit.
Good luck, and post it up one you're into it!
Well, started last week by pulling the engine/tranny and separating both, bring home the tranny.
Now, it's all disassembled except for the 1st motion shaft that I cant figure out how to get that nut off of the bearing side, front, as the gear won't just go through the case. It also seems to have lost a bit of the coating, but I will reuse anyway. Not making noise there, just 1st and reverse, that I hope a new layshaft and maybe 1st gear will clean up, with bearings.
The first motion shaft goes out thru the case - to the inside......it is held in place on the engine side by a lock ring. I remember locking the gear in the vice and then tightening the nut......then you push the assembly in thru the inside of the case. You have to leave it forward (bearing protruding thru the case on the clutch side as far as it will go) so that you can get the layshaft into place.
I think the kit from Victoria British is the easiest way to get the parts you'll need.....everything is in the kit except first gear, new synchros, gaskets, bearings and a new layshaft inner shaft and bearings.
BTW, I see this guy ever so often, he still hasn't used the gearbox, it's just sitting under his workbench. Instead he bought a Spitfire he's rebuilding, he sold the '68 Sprite without an engine to someone with a good motor and a rusty body.
Yeah, but I can't get the old one out! Does not seem happy drifting out the rear, above the largest. Beating myself up again. Will prob get it tomorrow, as has been the case with this job.
Found a good, used input shaft and other new layshafts & bearings from MM.
I think that will fix the odd noise from 1st gear.
Darn, if that guy doesn't want that box, ....i would make a reasonable offer! Let him know if it might work, please.
On somewhat a related subject, I came across this Datsun 5-speed gearbox (with a car and engine still attached) for sale. I know these are sometimes used as alternatives for Spridgets and Minors so I'm just throwing this out there since non-Z Datsuns have all but disappeared.
https://dallas.craigslist.org/dal/cto/d/1977-datsun-b210/6361140356.html
It won't come out if the laygear is still in place.....other than that it should just drift out - this is a ribcase transmission, right?
don't get the bearing cocked in the opening or it will bind.
I'll ask him what he wants for one of them......
good point Bruce, cheap way to get a 5 speed....probably need an adaptor kit too
Yep, definitely a ribcase. Laygear is there, but no shaft in place, so it's down in the hollow area of the case, won't interfere.
Must be I've managed to jam the bearing somehow....will retry, gently.
Yeah, a Datsun 5 speed is a good alternative, even those getting hard to find. But I'll go to many lengths to keep this part of the bugI of at least British origin.
It looks like the Rivergate 5-speed conversion kit is still available at http://www.rivergate5speed.com (http://www.rivergate5speed.com).
Looks like about $2000 if you do the speedo, including the trans - more if you need to o'haul your 5 speed before you install it. A lot cheaper than doing it to my E-Type!
Wouldn't be great if there was a Japanese 5-speed gearbox that we could fit to our classic Minis? Whenever I haven't driven my Mini for a while I find myself reaching for a non-existent 5th gear.
I do the same....constantly!
Hummmmmm
Pbraun, my friend said he'd take $500 for either of the two gearboxes I overhauled for him. That sounds pretty cheap to me as the parts were about $250.....that included all new synchros, new bearings, new layshaft and bearings and all the gaskets and seals.
Oh, well....... almost ready to reassemble mine now, with all the same new goodies. Just have to get all the bearing, springs and balls in the right places and right pieces.......
Would have taken you up on that a month ago before I ordered the parts.
Got everything rebuilt and back in the box, except the shift rods and forks. Then, just as I was falling asleep, I realized I had forgotten to shim the big rear bearing on both sides, as the direction sheet said. Oh, well, just have to tap that flange out, shim and reinstall. Must remember to put the front cover on, or something, to keep the layshaft from falling out when I turn the box upside down to drift in the flange and bearing straight. That's what happened yesterday. Soon, it will be easier after doing that PIA job 5 times yesterday! 11.gif
Ha! I feel your pain! For me one of the harder parts was getting the shims to hold still as I slid the tail of the gearbox on and bolted it up - it was far too easy for one of the shims to slip sideways just a tiny bit and get caught by the housing, but the shims I was working with weren't nice new flat ones.....
There is a definite order to how you assemble the internals, no question.....I had the first one apart and together about 5 times before I got it all in there correctly - the second one I did was MUCH easier!
Well, this is a timely refresher.....Sat I'm picking up another ribcase trans for an overhaul - this one is in a race car so it's a close ratio box I'm building for Clancy's newest box-Sprite racer - otherwise I'd just tell him to use one of the ones I already overhauled for Alan.
So, I need help. Put the shims (on the main shaft bearing) in as directed and now the bearing retainer doesn't sit flush with the case on the outside.
Dave - do you have any idea what could cause this?
I also need help with the balls, springs and detents. Do you still have that guide you could post or send along via email?
I must get this done right!
Thanks!!
I had issues with the shims on the bearings as they described in the instructions too, IIRC I reused the old shims.
I will find the link to the guide I used, but there are a number of detents and you do have to get them in the right places.....
I did find this.....
http://www.spridgetguru.com/TA0123.html (http://www.spridgetguru.com/TA0123.html)
And some info on the shifter
http://www.spridgetguru.com/TA0128.html (http://www.spridgetguru.com/TA0128.html)
Looks good , thanks you!!!!!
Let you know how it works out. Hope I don't shoot it first. ;D
If I ever get well again I have another one in my shop to build, so we'll see how it goes. Good luck with yours!
Just as a quick sanity check - when the main shaft bearing housing is correctly installed, it rests FLAT with the case, so the tail extension sits flat on top of it, correct?
That can be adjusted to some extent by the main shaft shims. At least, for example, if the shim on the inside is too thick, the bearing housing will protrude from the case. That was one of my mistakes, anyway. Among others.
Now, my next problem, other than getting over the flu, is I thought it was all set, but for installing the rear cover and shifter, but then when I put it in first, pop! and ping! and the three balls and springs in the slider fell out.
WIsh I knew what I done wrong. Maybe the slider was not oriented correctly. looked like too much room between it and third gear. could always see the synchro ring.
Anyway, I may be back at it in a week or so, if I feel ok. Any suggestions as to where to look?
Thanks in advance!
I hear you on the flu......mine turned into pneumonia and I spent a week in hospital, I'm out two weeks now and I'm still under the weather.....
You did have the front cover on when you went to shift it, right?
IIRC, if you used a screwdriver or whatever to move the shift fork, it can move too far and allow the balls to escape - not necessarily anything wrong in the trans, just that you moved it further than the fork would have been moved by the shift linkage itself, because the linkage is constrained by the detents and interlocks. The only way I know to put the balls and springs back is to take it back apart....it's possible that with enough hands and small screwdrivers you could coax them all back in in situ, but I doubt it.
Seems to me there was a lot of slop in the first gear/synchro, as much as I/8th inch but they tell me this is correct. The amount of play is controlled by the location of the front bearing, more shims between the bearing and first gear lessens the clearance.
When the rear housing is in place it does sit flat on the case, but you need shims between it and the rear bearing, and sometimes those come out of place when you're sliding the case over the rear mainshaft and cause it not to sit correctly, I put grease on the shims to hold them while I carefully slid the housing down into place.
Hope this helps, but my brain is still fuzzy from the flu.......I'll be better next week too.....I hope!
Humm, well, that does make sense about the first gear moving a bit too far and allowing the balls & springs to escape. Tomorrow I am going to study and go over the manual and drawings to try and make sure I'm doing everything right before it gets messed up once more.
getting close to asking if I can ship the dern thing out to see you. Cheers, and feel better!
Clancy dropped off another Sprite gearbox for me to evaluate - but this one is just a bit different - can anyone spot why he was excited to find this one? Hint - it's for his race car......
Check out on page 3 the last Sprite gearbox I rebuilt for comparison to this one....
Straight cut gears?
AND.......
Close ratio gears! Perfect for a race box.....
It looks a little grungy inside but Clancy has a device driven by an electric motor that will run the gearbox and allow him to shift it thru the gears - so we're going to fill it with diesel and run it for an hour or more - then drain it and do it again. Since these gearboxes run 30 wt motor oil it won't hurt and should clean it up - that will let us know if it has noisy bearings and needs to be gone thru. This is a back up box so it's not critical to be done right away.
Well, it's finally done! Not as clean as yours on the outside, but everything not up to spec replaced on the inside!
Last nuts going on, then into the bug-i.
Cool, this has been quite the project for you, glad to see you mastered it......now, into the car and drive it!
Yeah, and I didn't share about troubles getting the rear extension on........but all ok now - Into the car and out for driving!
Thanks for your help!
Quite a while ago (wow! March!) I posted some pics of a sprite Gearbox Clancy brought by for me to teardown and inspect and today I finally managed to get into it. Most of it looks salvageable, although I need to clean some parts up so I can inspect them thoroughly before I can say for sure. The one part that has me concerned is the laygear, if the inner bearing surfaces are damaged it may not be worthwhile to rebuild it....a new laygear is mucho dinero.....
It was a bitch kitty to get apart, things were rusted badly like it lay in water for a while, but only the reverse gear seems pitted and damaged, maybe it was laying over on its side? One of the screws that hold the shift forks in place, the head had completely rusted off, I had to weld a nut onto the end of the screw to get it out - and it was the one on the bottom of the reverse gear - but I knew a trick. I'll show Howie Didit later....
Well, bad news.....there is little to nothing left inside that is any good, so we're talking about where we're going from here. I found a set of close ratio gears that I could build from for a reasonable amount......I also sent a note off to MED as in watching a vid (Jemal from Mania) he mentioned that they sell dog shifters, gears, aluminum forks and other bits so I asked for a quote on those too.
Found a source for both the straight cut gearsets and the dog gearsets in the UK, now I just need Clancy to decide what he wants to spend on the box for his racecar.
Meanwhile, another Sprite gearbox has found its way into my shop - actually this is the second one he brought me, the first one was so torn up it would have taken a major amount of parts replacement to make it work again - this one out of a Lotus 7. He later confessed he thought his nephew might have done the damage trying to shift it into 1st while moving fairly quickly....there are no synchros on first in these gearboxes.
Anyway, after looking at all the needed parts for this one he's decided to build a straight cut gearset much like I'm going to do for Clancy.
The laygear on this one shows considerable wear too, hence the need to go all in and do the straight cut gears - the cost of the helical laygear is half that of the complete set of straight cuts, which include a new laygear too.
I've got most of the case and gears and shafts I'll be reusing all cleaned up, still have to clean the tailhousing and shifter box yet.
When I get parts in it will be a total rebuild instead of a freshening like he hoped to do.....all new gears and first motion shaft, new laygear, new bearings thru out, new tail shaft bushing and seal and of course all new gaskets and seals. We're also going with a modified front cover that uses a replaceable lip seal instead of the original, which used a reverse screw thread to keep the oil in the box - no seal of any kind.
I'm hoping Clancy will sell one of his project cars, if he does we're going to build a dog box for his Sprite - that will be a first for me.
OK, I got everything cleaned and ready for re-assembly, just waiting to hear from the owner on what gears he wants to use. He sent a note off to a company in England, haven't heard back from them yet.
The way most smaller companies in Europe tend to operate during the holidays, it may not be until next week before you hear back. (Lots tend to be closed for the two weeks covering Christmas to New Year.)
WillieB fired up his little lathe and made me a tool to pull the rear bushing out of the tail housing on the Sprite gearbox. It arrived in the mail today so I went straight down to the shop to try it....it worked perfectly!
I used the pusher tool to shove the old bushing in and then set up the acme thread and socket and pulled it right out again! Perfect!
Thanks WillieB!
A few pics to show how it works. First I used the pusher part to shove the old bushing back in the tail housing, then a pic showing it pressed fully in - the shoulder of the tool allows me to set the bushing at exactly the right height.
Then I assembled the tool with the acme thread rod and special nuts ($5 each!) and a large socket to receive the bushing and inserted it in the housing. I stopped part way so I could see if it was pushing it out straight - which it did beautifully.
Result!
My 6" Wilton vise sure makes these jobs easier as it holds big stuff like this securely.
Just what you had in mind. Looks like it works a treat. Now that I see the pics I really get how you are using it.
Ran into a snag with our little puller, turns out it works fine on a used bushing, not so much on a new one! Like trailing arm bushings on a Mini, they have to be reamed to size once in place, so I'll be sending the new bushing along with the tool back to Georgia to have WilieB work some more magic on it.
In the meantime the owner brought me another tail housing to use with a good rear bushing in it - we checked it with a driveshaft yoke to be sure - so I'll clean it all up and put a new rear seal in it and call it good. We also didn't like the looks of the shifter ball in the shift housing so he brought me another one of those too.
Today I assemble all the gears and bearings onto the shaft, dropped the laygear in and checked the shims then installed the reverse gear. Next in was the input shaft (or first motion shaft to some of you) and then the cluster. Once in place the first motion shaft slides back into place and then you raise up the laygear and slide the shaft in.
That's as far as I've gotten tonight, I'll probably have to take the whole shebang back out as I can't seem to thread the nut on the first motion shaft even tho it's new and the threads should be perfect.....so I may have to clean them up and I can't do that in the gearbox. It's always sumthin......
Finished up this gearbox today, as far as I could go. We have a new front cover coming - the original covers don't have a seal in them for the input shaft, rather a reverse thread on the inside of the cover which is supposed to redirect the oil back along the shaft into the gearbox. They leak.
The new cover has a machined boss and an actual seal in it - should work much better - but we don't have it yet, so I put the old cover on and he can run it like this till the new cover comes in then just swap them out.
I had mounted it up in my engine stand, but that really doesn't work so well, it's too low and makes me bend over, plus you can't reach the input shaft if you need to spin it or hold it in place.
I made some little temp brackets to hold bearings and detent springs in place while I checked the fit of all the parts inside and made sure it would shift easily, they worked well, but when I stood the trans on it's nose to install the tail housing the layshaft slid right out the front! ::) So I installed the front cover to hold it, then turned it up and put the tailhousing on. The gasket that goes on this end was not cut quite right, I had to enlarge or move the holes so that it would fit correctly, there is a locating pin on the rear bearing housing that dictates where all these pieces go, you can't just fake it! ;D
So it's mostly there, he didn't bring the rest of the parts that hold the shift lever in so I can't shift it much, the lever jumps up or binds without the top parts but I found a nice JPS shift knob (this trans is going in a 62 Lotus Super 7 - a real one, not a Caterham version) in my stuff that I got somewhere - brandy new - so I put it on for him. I have no idea where I get this stuff, it just shows up somehow!
Finally got all the parts in for the second gearbox - this one for Clancy's racecar.
He brought me this box last fall with a "no hurry" instruction, I finally took it apart in January and it was a mess. He swears it was dry inside but I could clearly see it had been at least 1/3 full of water, and things were not good. He had hoped it was just surface rust but when I got it apart - it was clear it was simply no good. 2nd and 3rd gears were "welded" to their shaft by rusted needle bearings - I had to drive the 3rd gear off with a 3 lb hammer and big drift - I tried pressing it off in my 20 ton press - wouldn't move a lick! - so the three pounder was pressed into service.
The pic of the two shafts tells the story.
Fortunately the owner of the silver box had a spare mainshaft Clancy could have and that's what I'll put in it this week as I get going on the build.
We also found a place that sells a front cover with an actual seal in it instead of the reverse thread that always leaks.
So all parts are here, I've already cleaned and painted the cases, still have some cleanup to do on some of the internal parts and all of the nuts, bolts and studs, plus I'll run a tap in all the holes to make sure all the threads are good.
Clancy's on his way to Phoenix today to deliver a racecar and will be back Friday - I should have it ready to go for him by then. He had taken all the gearbox cases and some other parts down to a blast place in North KC to have them dry ice blasted - they were NOT clean, so the guy didn't charge him for the job (which was expensive!) and I spent a lot of time cleaning the parts that they didn't........
Just buttoned Clancy's gear box up - just in time - he has the temp motor in the car and had it on the dyno today getting it ready to rent out to a guy for a driving school (hence the lower HP motor) and I think he would like to have this box in the car for the guy, and to get some race miles on it.
First pic shows the new cover with the front seal vs the old reverse screw style cover.
Last two pics - Clancy on the Dyno - said it made about 76 at the rear wheels.....again, plenty for a driver's school.
This is the first of the two latest gearboxes I built recently using straight cut gears, it's in a Lotus 7 and the owner came by to take me for a quick spin around the block as I wanted to hear how loud the gears were. It has a well built 1275 and it is very quick....of course it weighs all of 900lbs empty, more like 1300 with the two of us in it! He says it shifts well and he likes the taller gear ratios as with a stock box 1st was almost a throwaway gear.
Ran strong and of course - corners as if on rails.....too bad we didn't have a dash cam on to record that!