MrTomT

Hi List,

This just developed today & my mechanic is not back at work for a little while, so thought I'd see if this sounds familiar to anyone.

Noticed a bit of banging/knocking coming from the left rear wheel today. The sound got worse I become more concerned. Had to cut the trip short and come home.

The problem seems to have something to do with load as it's only there when going over bumps or cornering in right hand turns. it's like a mechanical clunking or banging.

I checked the underside of the car when I got home & all looks well from the limited view of the car I can get from looking underneath on my driveway. The shock & spring, roll bar, & suspension arms all seem to look normal.

Any help or advice would be appreciated.

Cheers,

Tom

Garth S

1) - check wheel nuts
2) - check 6 bolts holding inner CV joint to the differential ( inner axle)
3) - check outer 32mm axle nut, visible when the wheel center cap is pulled out of wheel center ( takes ~320 lb-ft of torque)
4) - check the CV joints ( & boots)

FBIII

How old are your shocks? It could be a worn lower shock grommet.

Mrmerlin

does the sound go away when you pull on the E brake handle while rolling?

JHowell37

What if it does?

atb

Mine made a clunking sound when I didn't torque the three shock tower bolts that come through the hatch floor, maybe take a quick torque wrench to them.

Tails

Please advise the year model and whether it is Auto or Manual as it will allow members to pinpoint the problem earlier.

My car developed a noise from the left hand rear when I went over a bumpy surface and it turned out to be the PSD system as one of the support brackets had fractured. The PSD system was installed from MY1990 IIRC.

Tails 1990 928S4 Auto

MrTomT

It's an 83 928S 5-speed with 85,000 km on it.
It sat in a garage for the last 15 years & going on the rest of the car I would say the shocks are original!
I've done just about all I can to it to get it up to A1 condition (all hoses, belts, etc... ) but yes, I hope it is just a shock absorber! I was thinking it could also maybe be a CV joint, but it's only when the suspension is under load on that side. e.g. straight ahead driving is fine.
I should also mention, apart from the disconcerting sound, the car feels fine.
I don't think it's the wheel contacting the guard - just does not sound like that, & although it does not have much clearance between the wheels and guards, that setup has not changed, so can't see why it would suddenly cause that.
Among other things my mechanic did just fit a new aerial in the back corner, but it looks secured on the bottom mounting and all the wheel arch trims look to be in place + my mechanic is no novice with 928s.

Thanks for all the help guys...

Tom

WallyP

Make sure that the battery isn't loose...

jimcat3

My 82 had a thunk in the inner weel right behind the tire.

Pull the tire and you see a 3/8" titanium rod running maybe 12" with a 7'8 rubber bushing and a light weld. Mine was undone, the casing around the bushing popped a Mcfrizzle.

Its an arm in the claven holder, maybe a product of the weissach axle - not sure - but certainly able to make a mild and yet annoying klunk swinging to that side (or was it after laying back down from the other side

Zut Alor.

Worth checking anyway.

ew928

Isn't the exhaust hanging out in the left rear as well.
Move the exhaust pipe around and see if it hits anything easily.
Wear gloves if the exhaust is still hot.