Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: Flyinace2000 on May 01, 2017, 06:37:21 AM

Title: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 06:37:21 AM
I've got a intermittent noise that goes away when accelerating (even the smallest amount of throttle) or braking.  Doesn't happen all the time either.  I don't feel it in the steering wheel or the shifter.  Wife says should could feel it under her feet (Right side passenger wheel).

Besides checking the lug nuts and if the wheel has any free play (wheel bearings, which are "new" as of 18 months ago), what else should i check?
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MPlayle on May 01, 2017, 06:51:22 AM
Also check the engine steady bushings.

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 07:20:26 AM
Quote from: MPlayle on May 01, 2017, 06:51:22 AM
Also check the engine steady bushings.

I did remove that a while back, put it back on, drove it, terrible noise of it not holding the engine.  Pulled back in, and and made sure it was torqued down.  Noise gone.  That was probably 6 months ago.  I'll recheck, but it doesn't sound the same.  Much lower in the engine bay.  Maybe a lower engine stabilizer is in order.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: 94touring on May 01, 2017, 07:30:00 AM
Steering rack loose or going bad internally.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 01, 2017, 10:42:37 AM
What type of gearbox are you using?  Mine is the remote shift, and the inner joints on mine are similar to u-joints, but rubber or upgraded rubber and plastic.  When they start to go bad, especially the right side they rattle against the exhaust.  I had a similar mystery noise and I'm in the process of replacing them. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 02:31:15 PM
Mine is the wand shift, 2 exposed shafts. Will a visual inspection show a fault? How much of a pain are they to replace and get to?
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: tmsmini on May 01, 2017, 02:45:08 PM
What type of drive shaft outputs do you have?
I am guessing pot joints with the description of the shift mechanism(2 exposed shafts).

Older outputs could bang on the exhaust slightly, if the steadies are not firm.
Terry
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MPlayle on May 01, 2017, 02:55:37 PM
Wand type shifter usually was the "Yoke" style outputs from the differential and those can hit the exhaust if the engine steadies allow the engine to rock any.

A picture of the drive shafts at the differential end will confirm the type.  If they have been hitting, a visual inspection of the exhaust down pipe as it passes the drive shaft coupling at the differential will show marks of the impact (scratches and dents).

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: BruceK on May 01, 2017, 03:19:36 PM
Besides all the other stuff mentioned, the fact your wife feels it down at the floor could indicate loose / worn rear subframe mounts.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 01, 2017, 03:22:01 PM
I think Bruce nailed it, broken rear subframe mount.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 05:36:10 PM
Alright, so took a bunch of photos

http://imgur.com/a/lYY8z

Rear subframes mounts don't look great....thoughts?  The U-Joints look really rough.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Willie_B on May 01, 2017, 05:58:52 PM
Hard to tell but do you have 2 bolts on each side at the rear of the front subframe?
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 01, 2017, 06:09:17 PM
I think those were pictures of the rear subframe mount.  I believe Bruce meant the rear bolts of the front subframe.  There should be 2 on each side at the rear of the front subframe where it bolts to the floor/toe board area.

Here's a link to the rubber ones.
http://www.minispares.com/product/Classic/Drivetrain/Driveshaft/GCD101.aspx?0803&ReturnUrl=/shop/classic/Drivetrain.aspx|Back%20to%20shop

These are the upgraded ones that are on my car.  I can see in the plastic edges of them where it's been hitting my header.  The description nails the noise I was hearing.  But mine is right hand drive, and I don't recall feeling anything from them.
http://www.minispares.com/product/classic/QL5000.aspx
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MPlayle on May 01, 2017, 06:27:14 PM
Definitely the "yoke" style outputs.  Yes, the rubber couplers look to have seen better days; however, they do not appear to have been hitting anything.

The lower steady on the drain plug side of the transmission case is a factory one from later cars and would have a dogbone going forward to a bracket on the front subframe.

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: BruceK on May 01, 2017, 06:40:45 PM
Quote from: Flyinace2000 on May 01, 2017, 02:31:15 PM
Mine is the wand shift, 2 exposed shafts...
That description is a bit confusing.   From the photo, you have a "rod change" remote gear change.  There is another kind typically called "magic wand" because of the long length of the shift lever that emerges down at the toeboard as opposed to straight up from the floor near driver's knee.

It is possible for the end of the remote shifter to bang around if the rubber mounts are broken.  But I think you'd notice how loose it feels when shifting if that were the case. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 07:03:23 PM
Quote from: BruceK on May 01, 2017, 06:40:45 PM
Quote from: Flyinace2000 on May 01, 2017, 02:31:15 PM
Mine is the wand shift, 2 exposed shafts...
That description is a bit confusing.   From the photo, you have a "rod change" remote gear change.  There is another kind typically called "magic wand" because of the long length of the shift lever that emerges down at the toeboard as opposed to straight up from the floor near driver's knee.

It is possible for the end of the remote shifter to bang around if the rubber mounts are broken.  But I think you'd notice how loose it feels when shifting if that were the case.
Yeah sorry, mixed them up.  My car is a rod change.  Also, i do not feel any of the thuds through the shifter or the steering wheel.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 07:05:03 PM
Quote from: Willie_B on May 01, 2017, 05:58:52 PM
Hard to tell but do you have 2 bolts on each side at the rear of the front subframe?

Passenger side has 1 and driver side has two.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 01, 2017, 07:12:02 PM
Full size links

http://imgur.com/jVmWKEl
http://imgur.com/H95JKIm
http://imgur.com/WBRjqx4
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: ADRay on May 02, 2017, 03:31:56 AM
pardon the pun, but this sounds familiar.

last summer, I thought I was hearing the brake line rattle under the passenger floor pan when I got off the throttle. by this spring, the rattle had become a slam. the problem was the rear subframe mounting point on the toeboard.

also not mentioned, but my initial thought from reading the title was maybe a bad ball joint. I would describe the sound of my bad ball joint as a clicking, rather than a thud though.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 02, 2017, 04:34:22 AM
Is it just me or does the subframe look to have been cut?  I ask cause I don't see a hole for the second bolt on the passenger side and the one on the drivers side that is flat with the floor seems really close to the edge.  I'll try to remember to take a look at mine when I get home to compare. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Willie_B on May 02, 2017, 04:45:24 AM
Quote from: gr8kornholio on May 02, 2017, 04:34:22 AM
Is it just me or does the subframe look to have been cut? 

That is what I was thinking. Will take some photos of one I have not in the car. Does not look loose though, but I would not want to drive it very hard that way.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 02, 2017, 06:05:19 AM
There is a 68 morris mini on BaT with some good shots of the front subframe bolts at the floor area.

(http://bringatrailer.com/wp-content/uploads/2017/04/IMG_9482-1.jpg)
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MPlayle on May 02, 2017, 06:26:59 AM
From the looks, it appears to be a pre-1976 "two bolt" subframe.  As such, it does not have the padded mounts between the back ears of the subframe and the floor.  That said, it should have two bolts per side as shown in the pictures gr8kornholio posted. 

I tend to agree that it looks as though the one side has been cut at some point, losing the second bolt position.  There should still be a hole in the floor though unless that got welded up at some point.

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Willie_B on May 02, 2017, 08:31:02 AM
For sure some missing metal there.
Photos of one of mine.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 12:26:11 PM
Quote from: Willie_B on May 02, 2017, 08:31:02 AM
For sure some missing metal there.
Photos of one of mine.

Well here is what my floors looked like 12 months ago.  I think i see 2 bolts above and to the right of the tranmissin tunnell, or is that something else?

(https://c1.staticflickr.com/2/1671/24559864859_4a750dedb7_k.jpg) (https://flic.kr/p/DqgJaR)20160208_113022 (https://flic.kr/p/DqgJaR) by William J Sisti (https://www.flickr.com/photos/willsisti/), on Flickr
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 12:29:22 PM
See attached for possible bolts....
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 02, 2017, 12:43:57 PM
What's odd with this pick is I see the two bolts on the right, but can only make out one on the left.  Which is opposite from the underneath shot, yes taking into account the car being flipped.  Hopefully. 

The subframe bolts on the right side of that pic are left of the tunnel, right where the toe board starts going up at an angle.  The one is on the angled area the other is on the flat part of the floor.  You can see the bottom of the bolt protruding below the floor from the cut out. (just saw updated pic, it's the bottom two)
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 12:49:28 PM
Quote from: gr8kornholio on May 02, 2017, 12:43:57 PM
What's odd with this pick is I see the two bolts on the right, but can only make out one on the left.  Which is opposite from the underneath shot, yes taking into account the car being flipped.  Hopefully. 

The subframe bolts on the right side of that pic are left of the tunnel, right where the toe board starts going up at an angle.  The one is on the angled area the other is on the flat part of the floor.  You can see the bottom of the bolt protruding below the floor from the cut out. (just saw updated pic, it's the bottom two)
My body shop wasn't exactly a detail oriented guy.  I'm willing to bet he just forgot to re-drill a hole for the mount after replacing the floor.

On this photo
http://imgur.com/WBRjqx4

Do you see a small hole at the corner?  Maybe i just need to move the carpet, redrill the hole, and put in a bolt. I could also check the other 3 bolts.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Willie_B on May 02, 2017, 01:00:43 PM
The ones several inches above and to both sides of the tunnel are for the steering rack.  The subframe ones will be right at the floor bend.

It looks like the body shop guy cut off the other bolt and subframe part when replacing the floor.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 02, 2017, 01:32:32 PM
never mind, asked and answered already.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 01:35:33 PM
He could of cut it or it could of rusted away.  Either way....its done now and this is just another reason i will never use that guy again. 

Here is an older photo from under the car.  Not a great shot, but does it help?

https://goo.gl/photos/5A1cQTwU5PzXZkkt6

Pre-restoration photo
https://goo.gl/photos/Sh7BZdGtjdEoCkJg8

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 02, 2017, 01:38:34 PM
Is it just me or is that a really odd place for the accelerator pedal?
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 01:48:47 PM
A few more photos of the new floor pans.

https://goo.gl/photos/9qFoFfwyWbuMZCsB9

You can see one bolt hole on the driver side.  I'm gonna say he forgot to drill a second hole on the passenger side. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 02, 2017, 01:55:21 PM
Quote from: MiniDave on May 02, 2017, 01:38:34 PM
Is it just me or is that a really odd place for the accelerator pedal?

Whats strange about it?
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 02, 2017, 02:22:36 PM
It's mounted to the floor, first of all, secondly it's so far back.....

All the Minis I've owned or driven have a suspended acc pedal - not saying it was never done this way, just that I've never seen it......

(https://s-media-cache-ak0.pinimg.com/600x315/a4/f6/12/a4f6129e77a9a6475230a2aba188d22d.jpg)

(https://lh3.googleusercontent.com/7XM271itGdjqALsgg4zp4dF0eN5_iFVBeHhoDvbZeALTYAlg6LKs-Kwl4s-POTtzKIJrfeQ2IAqY_YtEF9DT4geahVHVWhnqfFBy1Ypi7pZrgl2xupTlWAjmASqV8FkEpdaMdQy4bZ2CBzhxZowOrs9Zcp_H-pJI7on0Wr2mRnNMO9Z1uByD285t8uDUmwxE6rCZ6i6pePp4Kxs_Y8JDyxfrcS8Y6R0s4-qpN1SZoflypbVhavYlFLy9L4yD_kh4isKPjINrxv2_Ab7bem7EAtkfZg7NFowj1dkDOfcrrqGy5p3I9ehvgO-m_D8lI6L5FcQ7G8pjmCK4uN189Q3HVwT6BMhpplkLH4bwwu_wZZ8LedD6LEdn_BdZx6Gp4xPf_lfWbSyVjoqAeVZpifeqB-ED4os0mPHEnLGw-9vxYqLLwhZCuEjaUA3-yY6Ox8dxCnHRo6Th_6zfzG0y8WqqrT7FrkjO_hW5XkfTBE-tErJmpH0rlaonokV2_Rdrx6Tl34q8RqGPFAXEgpcjsftTiE0cEkYj9j_D2NDjBCY_Ku1AmooL7nR_Opoq758vCgjdE3-Fc8vaT7OVWrSoxJyoCJO5oPNSQ58hT89Gf-4OtbczVh2Ptef84gdccxrNgYVa7HG4-lgl3JdBZpYm2TqOK9vMu5dM0CfURc_OvyZjLGI=w1268-h713-no)
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MPlayle on May 02, 2017, 02:34:42 PM
Some of the Innocenti Minis had the floor-mounted accelerator pedal.  One of those Italian only things.

Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 08, 2017, 06:30:42 PM
Sometimes it's the easiest answer.... I had a loose lug nut. :-( 

On the plus side I tighten  up some of the exhaust clamps and steady while under there.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 09, 2017, 04:13:05 AM
Glad you found it, now back to happy motoring. 71.gif
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 09, 2017, 07:57:59 AM
Quote from: gr8kornholio on May 09, 2017, 04:13:05 AM
Glad you found it, now back to happy motoring. 71.gif

Have to get my clutch to stock leaking fluids first! :-)

http://www.restorationmini.com/forum/index.php?topic=1336.0 (http://www.restorationmini.com/forum/index.php?topic=1336.0)
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 09, 2017, 08:10:13 AM
Yea, as Bruce posted in another thread, always something.  I'm waiting on the parts I mentioned earlier to fix them from hitting the exhaust. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 09, 2017, 08:42:12 AM
Yes, but once you get them to a critical mass, it seems like they'll go along for years with just a little routine maintenance. That's what's wrong with 95% of these cars, they require routine minor attention and they don't get it. Today's cars are pretty much drive it and forget it, where these cars require regular hands on work....and since that hasn't been done we spend a lot of money and time trying to get them back to a useable state.

Look at the rear suspension on my Racing Green car, it looks like it hasn't been greased in decades, consequently the bearings get dry or water gets in them and they deteriorate - all for the sake of 5 min and a couple of pump with a grease gun. Conversely, now that I have rebuilt them and lubed them properly, I expect them to last as long as I own the car.....and more.

I bought what I thought was a decently well kept car, but I have so far rebuilt the entire brake and suspension systems on the whole thing, repacked or replaced wheel bearings, new tires and so on. But once done, the car seems to be pretty daily driveable....it always starts, doesn't run hot and next time I change the oil I'll replace the shift shaft seal - the only place it's leaking oil.....for now!

My old car Buzz is another case in point, I rebuilt the engine and whole front end on that one too, but it's done more than 20K miles without a hitch since.

Moral of the story, they always need way more work than we think, but once you do it all - and do it right - it can be a reliable car.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: gr8kornholio on May 09, 2017, 10:49:41 AM
And that's why I'm building up this pile of parts.  Going to get all the stuff that was probably neglected put back right and enjoy the wheels off of it.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 09, 2017, 01:03:45 PM
There you go.... 4.gif
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: MiniDave on May 09, 2017, 01:06:30 PM
Oh, and Flyinace......I've had to replace the slave on every Mini I've owned at some point, seems almost like a maintenance item now.

I think Dan keeps a clutch master and slave on hand all the time......
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 10, 2017, 04:32:48 AM
Order from MiniSpares shows up tonight. She'll be back on the road again by Friday.
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: 94touring on May 10, 2017, 06:03:00 AM
I'll echo what Dave said.  Typically I've had to replace all the hydraulics and/or all the suspension in one shot.  Or even the whole fuel system.  But then they last ages and pretty reliably. 
Title: Re: Thud Thud Thud when coasting, sometimes
Post by: Flyinace2000 on May 10, 2017, 01:26:00 PM
Quote from: 94touring on May 10, 2017, 06:03:00 AM
I'll echo what Dave said.  Typically I've had to replace all the hydraulics and/or all the suspension in one shot.  Or even the whole fuel system.  But then they last ages and pretty reliably.

Most of my brake system is new, that was my first project when I got the car.