Thud Thud Thud when coasting, sometimes

Started by Flyinace2000, May 01, 2017, 06:37:21 AM

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Flyinace2000

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?

MPlayle


Flyinace2000

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.

94touring

Steering rack loose or going bad internally.

gr8kornholio

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. 
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

Flyinace2000

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?

tmsmini

#6
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

MPlayle

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).


BruceK

Besides all the other stuff mentioned, the fact your wife feels it down at the floor could indicate loose / worn rear subframe mounts.
1988 Austin Mini
2002 MINI Cooper S
1992 Toyota LiteAce (JDM)
1997 Jeep Wrangler Sahara

MiniDave

I think Bruce nailed it, broken rear subframe mount.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Flyinace2000

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.

Willie_B

Hard to tell but do you have 2 bolts on each side at the rear of the front subframe?

gr8kornholio

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
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

MPlayle

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.


BruceK

#14
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. 
1988 Austin Mini
2002 MINI Cooper S
1992 Toyota LiteAce (JDM)
1997 Jeep Wrangler Sahara

Flyinace2000

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.

Flyinace2000

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.


ADRay

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.
1982 Mini 1000 HL
@andyray998

gr8kornholio

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. 
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

Willie_B

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.

gr8kornholio

There is a 68 morris mini on BaT with some good shots of the front subframe bolts at the floor area.

I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

MPlayle

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.


Willie_B

For sure some missing metal there.
Photos of one of mine.

Flyinace2000

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?

20160208_113022 by William J Sisti, on Flickr