What's making that knocking noise?

CatmanV2

Member
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28,824
Opportunity?

Seriously, just got the GT back with new NS track rod end. Now goes in the direction the steering wheel goes, which is super :) I'd forgotten what it's really like.

But the original symptom remains and our (breifish) examination couldn't find fault with anything else (particularly bushes)

Full left lock and reverse gives you a clonk you can feel and sounds like it's coming from the OSF wheel. Also seems to match wheel rotation (which makes no sense to me at all*

Any thoughts

TIA

C

*This is not an unusual state of affairs but I suddenly wonder if there's a balance weight on the inside of the wheel fouling on something....
 

Oneball

Member
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1,261
My 3200 used to do that when reversing out of my parent's drive, since I've changed the rack it hasn't done it.
 

Oneball

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1,261
When you jacked it up there was obvious play at the wheel, I thought it was the TRE to start with.
 

Zep

Moderator
Messages
2,422
Opportunity?

Seriously, just got the GT back with new NS track rod end. Now goes in the direction the steering wheel goes, which is super :) I'd forgotten what it's really like.

But the original symptom remains and our (breifish) examination couldn't find fault with anything else (particularly bushes)

Full left lock and reverse gives you a clonk you can feel and sounds like it's coming from the OSF wheel. Also seems to match wheel rotation (which makes no sense to me at all*

Any thoughts

TIA

C

*This is not an unusual state of affairs but I suddenly wonder if there's a balance weight on the inside of the wheel fouling on something....
Do you feel it through the steering or body? Is it the same on a smooth surface and a lumpier one?
 

CatmanV2

Member
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28,824
When you jacked it up there was obvious play at the wheel, I thought it was the TRE to start with.
Huh? Were you there?

There *was* play at the NS wheel which we tracked down to the TRE. That's not cured the clunk.

C
 

CatmanV2

Member
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28,824
Is it not just wheel slip ? (Sorry I’m not being rude but presumed that’s what it is on mine )
I thought it was at first but I don't *think* so. I should probably find an empty carpark and reverse around it for a bit.

C
 

CatmanV2

Member
Messages
28,824
Do you feel it through the steering or body? Is it the same on a smooth surface and a lumpier one?
Body I think, although now you've asked I might have to check again. Seems to be worse on smooth (for example it doesn't do it when I reverse into the drive which (as you'll recall) is mostly gravel. The bushes though *did* clunk going into the drive. I wonder if it is just the wheel skipping a lot.

C
 

Mattp

Member
Messages
371
I thought it was at first but I don't *think* so. I should probably find an empty carpark and reverse around it for a bit.

C
Much like Oliver, could it just be wheel slip/diff locking up

My Alfa used to do this, from the front only on full lock (low speed obviously!) - wrong driven wheels, but are you sure its coming through the front? anyway was really bad on one particular brand of tyre - to the extent that I thought Id smanglized the LSD. changed tyres and it went away - totally non existent with the current Kumho tyres unless its very cold and the ground is damp.
 

CatmanV2

Member
Messages
28,824
Much like Oliver, could it just be wheel slip/diff locking up

My Alfa used to do this, from the front only on full lock (low speed obviously!) - wrong driven wheels, but are you sure its coming through the front? anyway was really bad on one particular brand of tyre - to the extent that I thought Id smanglized the LSD. changed tyres and it went away - totally non existent with the current Kumho tyres unless its very cold and the ground is damp.
Pretty sure it's the front, yes, but.....

Maybe I can see if if Mrs C drives it

Cheers
C
 

Oliver6796

Member
Messages
483
I thought it was at first but I don't *think* so. I should probably find an empty carpark and reverse around it for a bit.

C
Mine does it (perhaps past as ive changed tyres but not had it on full lock in reverse yet) quite bad, at first I thought oh balls something really mechanical clunking.
 

Oneball

Member
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1,261
If it does it on dry tarmac but not on gravel, I'm with Oliver, it's probably tyre skip.
 

CatmanV2

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28,824
This is encouraging. Didn't used to do it but the tyres are getting to the end of their useful life.

Cheers

C
 

conaero

Forum Owner
Messages
29,013
Change of direction on lock is 9/10 roll bar bushes.

If it only does it after the cars been stood for a while and only on the first sharp turn then this is the diff and normal. Lack of lubrication as all the oil is in the bottom of the casing coupled with dry gears and put it under maximums stress, it’s is more of a whirring than a clock though.
 
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Oliver6796

Member
Messages
483
This is encouraging. Didn't used to do it but the tyres are getting to the end of their useful life.

Cheers

C
I feel a tyre sales punt lol. Oh hold on mine did it with the Pirelli’s I’m selling ! I’ll be out in the car over the next few days so will see if it’s still doing it with the Michelin’s on.
 

CatmanV2

Member
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28,824
Change of direction on lock is 9/10 roll bar bushes.

If it only does it after the cars been stood for a while and only on the first sharp turn then this is the diff and normal. Lack of lubrication as all the oil is in the bottom of the casing coupled with dry gears and put it under maximums stress, it’s is more of a whirring than a clock though.
Does it pretty repeatably, no matter if it's been standing.. How do you mean 'change of direction on lock', Matt? Pretty sure we checked the ARB when we were under there.

Cheers

C
 

CatmanV2

Member
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28,824
Well, after my saying it was consistently re-producible, I noticed that the Homebase car park was nice and empty. So I thought I'd re-produce it.
Could I ********. Neither direction. So I guess it was just a fluke of the surface when I pulled out of Feli's (ooooerr) or it is just tyre skip. Happy days.
C