Noise from rear corner

For classic Porsche 911 content

Moderators: hot66, impmad2000, Barry, Viv_Surby, Derek, Mike Usiskin

Post Reply
sfh3l
DDK addict
Posts: 126
Joined: Fri Jan 06, 2012 4:55 pm
Location: Buckinghamshire, United Kingdom

Noise from rear corner

Post by sfh3l »

My '72 T has just started making a creaking noise from the left-hand rear. As the car goes over bigger bumps when that side is under load, the noise is apparent. If the car had anti-roll bars (which it doesn't), I'd say it almost sounds like a dry or worn ARB linkage or bush. Clearly, in the absence of any such thing, I am thing perhaps a noisy damper or worn top mount? Does this sound more likely than anything at the trailing arm or torsion bar end of things?

I confess to not having been under the car yet as I have been so busy and not really used it either, but I was hoping to have a slightly more focused dip into it, having asked your collective wisdom on here.

Thanks in advance chaps, as ever and stay safe.
Best wishes,

Sam.

'72 911T - '08 Boxster 2.7 Sport Ed - 997 GTS - '72 3.0csl - 1990 Z1 - Austin 7 Ulster Replica - Derelict 1925 Rolls Royce
User avatar
hot66
Moderator
Posts: 19269
Joined: Tue Nov 11, 2003 4:17 pm
Location: North Yorkshire

Re: Noise from rear corner

Post by hot66 »

could be :

torsion bar bushes ( 2 of them on the outer end of the torsion bar ) ?
shock bushes ?

they're the 2 obvious ones .. also the inner a-arm bush
James

1973 911 2.4S
1993 964 C2
2010 987 Spyder

1963 Honda C100 Supercub

Its not how fast you go, but how you go fast ;)
Magnum
DDK slapper chatter
Posts: 476
Joined: Tue Apr 08, 2008 4:29 pm
Location: Cape Town, South Africa

Re: Noise from rear corner

Post by Magnum »

Hi Sam

Hope all is well? Strangely my '72T has exactly the same symptom - mine is evident when going over the "sleeping policeman" style of speed bumps - ie short/sharp movement in the rear suspension taken at slow speed and almost sounds like it's coming out the B pillar.

Initially gave me a fright it sounded so terrible ( when i first had the car) ...i've also not looked in detail but the rear shocks/bushing are all good so can discount that. I have (reasonably confidently) pinned it down to the torsion bar bushings, but still need to squish my son into the back with his ear to the tub and repeatedly simulate. I'm guessing it's probably the outer surface rotating in the tube.

It's possible, my car being a hot rod, that these bushing were changed to poly bushes in the past, and this is the sort of noise i suspect they make...which is why people moan about them? Is that the case?

Good luck and keep us updated? when you dig deeper?

Cheers
Magnus

1972 3.2 RS lightweight. Still a bit scary...
1987 3.2 Carrera. Sold..
1972 Alfa 1750 GTV. Sold...
1971 911E in Silver. So lovely, sold..
1971 911S. sold....
1972 BMW CSL. Stupidly sold...
1968 Land Rover SIIa SWB..rusted in half...
jwhillracer
Me and DDK sitting in a tree! KISSING
Posts: 2907
Joined: Fri Apr 18, 2008 5:58 pm
Location: Sunny Somerset, just above the water....

Re: Noise from rear corner

Post by jwhillracer »

All of the above suggestions, plus on our 72 Hillclimb car, the holes in the inner suspension arm supports had worn oval, giving a similar clonk to the one you describe, as the swivel bolt moved.

JW
Life's a single timed run with no practice....
1963 Porsche 109 Junior
1970 914/6 2.4E/Webers
1970 VW Beetle project
1972 911 Hillclimber part of the family for 40 years!
2006 Hymer Merc Starline 630
2000 T4 Van LPG
2000 Golf V5 Estate GT
DarthMJH
I luv DDK!
Posts: 893
Joined: Sun Oct 09, 2011 10:47 am
Location: NW London

Re: Noise from rear corner

Post by DarthMJH »

My 73 T had the same issue and it was what James said: torsion bar bushes
Mike
1973 RHD 911T viewtopic.php?t=73984
1995 993 C4 (Gone but not forgotten)
sfh3l
DDK addict
Posts: 126
Joined: Fri Jan 06, 2012 4:55 pm
Location: Buckinghamshire, United Kingdom

Re: Noise from rear corner

Post by sfh3l »

Thanks Chaps,

That was predictable excellent and thorough. What a great community this is! 'Magnum' has put it better than I did and his, along with your other responses makes me convinced that the problem lies with the T/B bushes. I will book the car into my local, Tuthills to have it sorted as I don't feel confident that I will get the ride height and so on correct afterwards if I do it. The 911 is the only car I've ever owned with torsion bars and I'm still a little in awe of the whole set up.

Thanks again to you all and my best wishes.

Stay safe and enjoy your cars :-)
Best wishes,

Sam.

'72 911T - '08 Boxster 2.7 Sport Ed - 997 GTS - '72 3.0csl - 1990 Z1 - Austin 7 Ulster Replica - Derelict 1925 Rolls Royce
Post Reply