Rebuilding rear swing arms

Started by MPlayle, May 24, 2023, 09:08:08 AM

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MPlayle

Background: I have been diligent about lubing the suspension on my Mini Van since I got it, but the prior history is unknown.  On the recent Ozarks drives, I got suspicious about the overall condition of both the front and rear suspensions.  (I already had determined the front ball joints were going to need addressing before too long.)

The plan: I am going to rebuild both the front and rear suspensions.  For the front, I am going to put in new rubber cones, new knuckle joints, rebuild the upper arms, replace the ball joints with the "maintenance free" kind, and replace the shocks.  For the rears, I am going to put in new rubber cones, new knuckle joints, new shocks, and rebuild the swing arms.  I am also going to reset the front toe as it has a little too much toe out as evidenced by tire wear on the inner edges from the spirited driving in the Ozarks.

I have ordered the parts I will need including the rebuild kits for the front upper ams and rear swing arms.

The rear swing arms come with a bearing for one end and a bronze bushing for the other.  I know the bushing needs reamed to fit.  I have been told by Dave that Dan has a special made tool for that job and he might be open to loaning me the tool.

The questions: During reading up on the process for the rear arms, there was a notation about certain years having bushings at both ends and I seem to recall someone mentioning that some years also had bearings at both ends.  Does anyone know background details and if I could go with bearings at both ends?  Also, I have extra pare bearings for the front arms - are these the same as the bearings for the rear arms?

My thoughts: I could save the reaming process by going with bearings at both ends and possibly use some of the spare bearings I have if they will work (are the correct size).

Comments?



Tim

The bushed hole is a different diameter to the bearing hole in the rear arms.  Also, the front bearings and rear bearings are different sizes.  The bearings that come with the rebuild kits are offshore no-names typically.  You can order quality ones locally.  I'll look up the bearing number once I'm home and let you know what I bought for mine.  They were cheap enough and I know they won't let me down.

Tim

Scargo

My only comment is, luckily you can probably pick up all the parts needed for your "Suburban" from your local Chevy dealer.

MPlayle

Started some of the tear down today while waiting for the parts order to get out of FedEx customs hold.  It seems anytime an overseas order has the word "kit" on the parts list, customs wants a complete detailed list of the "kit" contents and itemized costs of the order.  They are also "lazy" about processing the information when they get it as apparently MiniSport provided it on Friday and I provided it on Saturday but as of today it was still "on hold" pending the information already provided.

Back to the teardown: Car is up on stands, wheels are off, got the steering rod ends loosened to adjust toe-out when I get the rest of the front finished, got the rear shocks out, got the rear trumpets/cones/knuckle joints out (came out all as one unit well stuck together).  I had to struggle with separating the cones from the trumpets and knocking out the knuckle joints.  Thankfully I still had a long steel rod to run down the trumpet to use to knock out the knuckle joints after letting them soak in penetrating oil for a bit.

Next is to review the Haynes manual for how to remove/disassemble the rear radius arms.

MiniDave

Don't do it if they don't have play/wear in them, just grease them up and call it good.
Complete failure at retirement - but getting better!

1972 Mini Racing Green
1972 Mini ST hotrod
2017 Audi Allroad - Glacier White - His
2018 Audi Allroad - Floret Silver - Hers

MPlayle

What I don't know is how to tell if there is play/wear in them other than taking them apart and visually inspecting them.

How do you determine if there is play/wear?

MiniDave

Unhook the shock, let the arm droop too take the spring tension off and grab the end and try to move it in and out and see if there is play in it. Move it up and down and see if it moves smoothly.....
Complete failure at retirement - but getting better!

1972 Mini Racing Green
1972 Mini ST hotrod
2017 Audi Allroad - Glacier White - His
2018 Audi Allroad - Floret Silver - Hers

MPlayle

Thanks!

I already have the shocks and springs out.  I suspected needing new springs and found I definitely need new knuckle joints in the rear - rubber dust covers had pulled loose and the ball of the joints were dry and what little grease was present was dirty.  (I haven't yet inspected the cups as they are still in the radius arms.)


MPlayle

Still waiting on FedEx to get my shipment cleared through customs - it has been on hold for a week now.  The requested shipment details were also provided a week ago.  I have been trying every day this week to find out why it is still on hold and no results - no follow-up from FedEx on any inquiries.

Meanwhile, I have been continuing with the disassembly and assessment of the suspension needs.  I dug the old knuckle joint cups out from the rear swing arms and followed Dave's suggestions for checking the wear.  The rotate smoothly and seem to have no play in them.  I will grease them up again and assemble with the new knuckle joints, rubber cones, and shocks when the parts arrive.

I also began the disassembly of the fronts.  I pulled off the front hubs and drive shafts (separating the pot joints) and removed the front shocks.  Next will be pulling the upper arms, and removing the front knuckle joints, trumpets and rubber cones.

I amy also try to address the oil leak at the differential cover while I have it in the air.  It will be cramped, but I think I can do it without pulling the engine.

I also replaced the side seam trim that came loose during the Ozarks drives.  I got some chromed plastic style trim from the regualr parts store.  It fits nicely, though it is a bit narrower than what came off.  It allowed me to use some clear zip-ties to secure it in a few stategic places along the length from front to rear.

tmsmini

#9
There were some articles on either the Mini Forum or the MK1 forum about checking and rebuilding the rear arms. One of them applied to hydro arms, but much would be the same.
I will try to find the links.

This is one:
https://mk1-performance-conversions.co.uk/rad-rep.html

tmsmini

#10
You might also consider these:

https://shop.catmint.biz/product/radius-arm-lubricating-tube-steel-21a396/

Not sure who else sells them now, but the plastic tubes just don't last.

If you end up rebuilding the arms and are interested in the metal tubes, I have a set. I ended up trading a set of hydro arms for dry that were already rebuilt. So I won't need the tube in the near future as I am not going to take the arms apart to install the tubes.
I will order some replacements at some point. That way you do not have to wait for another customs quarantine period...


MPlayle

tmsmini,

You wouldn't by chance also have a set of standard front suspension trumpets as well?  If you have both, I am definitely interested.  I don't have to rebuild my rears right now, but they will likely need done sometime in the future and having the steel tubes handy would be nice.

It seems the knuckle joints (steel) have welded themselves into my car's front trumpets (aluminum) and won't break loose.

Anyone got a set left over/laying around they are willing to part with?

I'll post a request for front trumptes in the parts section as well.

tmsmini

Let me check on the front trumpets, pretty sure I do.

tmsmini

#13
Trumpets 21A530

IMG_0830.jpeg

MPlayle

#14
I see MiniSpares has those in stock as an option.

Did you have any to go with the steel tubes you mentioned?

If so, PM me and we will discuss details.

Edit:
Tracking shows my existing parts order finally cleared customs and is scheduled for Monday delivery.

MPlayle

Right now I hate FedEx.  My shipment has not moved at all since clearing customs on Saturday.  I had to call them again today to chase it down as tracking just shows it "pending" and still sitting at their Ft. Worth, Texas hub.

I did receive a package from Terry (tmsmini) with the steel grease tubes and a set of front trumpets.  Thanks Terry!

I spent a bit of today taking more of the fronts apart as well.  I need to clean up the front upper arms so they are ready for installing the rebuild kits when they arrive.  Both shafts showed mild score marks from the bearings and both front rubber cones were toast (totally squashed).

I still need to remove the old ball joints from both hubs and clean the upper arms.  I also want to crawl under and see if I can fix the diff cover oil leak without pulling the engine while the hubs/axels are still out of the car.

MiniDave

Fed Ex is why I find it difficult to order stuff from MiniSport
Complete failure at retirement - but getting better!

1972 Mini Racing Green
1972 Mini ST hotrod
2017 Audi Allroad - Glacier White - His
2018 Audi Allroad - Floret Silver - Hers

MPlayle

Well, the parts order arrived last Thursday and today was the first day I have had any time to get back to the project.  I only managed to get one rear reassembled today before I melted and that one was a bit of a bear to do.  It turned out I had to notch the new rubber cone to make it fit over a couple of repair welds holding the cone seat to the subframe.  Hopefully, I will have some time tomorrow to try for the other rear.

MPlayle

Did not get another crack at the Mini until this morning.  I got the other rear done, the oil drained and both front upper arms cleaned up.  Then I was melted and squishing in my clothes.  The heat index is already about 105* (temps sitting at 90*-93* and expected to climb to 101* by late afternoon).

I may get another chance to work on it Sunday morning.  Progress reports as they happen.


MPlayle

Progess report for Sunday/Monday: I have both fronts ready for reassembly - new ball joints installed and greased, new bearings in the upper arms, and the new upper arm shafts ready to go in.  Not much for progress, I know.  With temps hitting 100*+ by 2:00 p.m. and heat indexes running 109* to 112*, I don't last very long in the open garage.

With temps all week supposed to be over 100*, it is going to be slow progress in small stages.


MiniDave

Ah.............Texas in the summertime. You should have taken it over to Bruce's nice air conditioned garage. I can't function in the summer in mine without A/C.....
Complete failure at retirement - but getting better!

1972 Mini Racing Green
1972 Mini ST hotrod
2017 Audi Allroad - Glacier White - His
2018 Audi Allroad - Floret Silver - Hers

MPlayle

Got a bit more done today.  I checked whether I could actually pull the differential cover with the engine in the car to fix the oil leak and that is a "no-go" - not enough room between the diff and the rear crossmember of the front subframe.

I did get the right front upper arm assembled and installed along with the new rubber doughnut, new standard trumpet, and new knuckle joint.

It is slowly coming back together.

MPlayle

I got another chance today to work some more on the Mini.  I got the left front upper arm installed with its new rubber cone, trumpet, and new knuckle joint.  I also got both new front shock installed and the upper arms lubed.

Next is to begin the engine removal for trying to fix the oil leak.


MPlayle

Got an early start today so I managed to get more done than I had hoped: I got the engine all the way out of the car and on the bench before I melted.

MPlayle

Wednesday I got the speedometer drive changed out to hopefully make the speedometer a little less inaccurate (was running 18% over actual) and the diff cover fully removed.  I also got the transmission side mating surfaces cleaned for receiving the new gaskets.

Today, I got all the gasket surfaces on the differential cleaned and the new gaskets installed with a thin coating of grey Permatex gasket maker/sealer applied before reassembling the differential onto the back of the transmission.  I will be letting that set/cure for a few days before attempting to leak test before putting the engine back in the car.