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Master Q · Joined: 08 Jul 2006 Posts: 10 Location: Near Edinburgh

Car was running like a watch until earlier today. After a mildly 'spirited' blast along a short road followed by quick deceleration I now find my car is making a sort of scrape-scrape sound from (I'm 90% certain; I have hearing problems) the rear......

The sound is rhythmical, road speed related, worse under increasing load (i.e. when taking off, accelerating, climbing hills etc) almost inaudible cruising at higher speed (say 50MPH) and returns less badly under engine braking. Dropping the clutch or coasting the sound IS gone.....

So, I'm thinking driveshafts? CV joints? It's a filthy day here and I've not had the time to have a look?

Your opinions guesses and dire warnings would be much appreciated.

Incidentally the car is an '83 RHD 924 2.0 Non-Turbo (UK spec) with 5-speed manual transmission.

Ozzie · Posted: Thu Dec 14, 2006 6:13 am Post subject:

I'd also check the wheel bearings or brake assemblies.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Smoothie · Posted: Thu Dec 14, 2006 6:31 am Post subject:

Have a look at them, but CVs wouldn't be my first guess with a scraping sound - they normally go with a clunking or clicking.
My first choice would be a tire rubbing (specifically the rear-left because due to a manufacturing anomaly that seems to be common to all 924-944-951, there's a bit less tire-to-wheel-opening clearance at the rear-left.) Check the tire for any sidewall bulges. -Hit any potholes lately?
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

tj924 · Posted: Thu Dec 14, 2006 7:10 am Post subject:

Assuming rear drums, check that your hub nut is tight (huge nut, 36mm) & has a cotter pin installed. One of mine was loose (had a cotter pin, thank God) & I had the same symptoms as you. With the hub nut loose the brake drum will start to work loose & you get that scaping sound.

If it is a loose hub nut, disassemble the axle on that side & repack the bearings.
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TJ
Silver '82 924 NA 5-Speed Manual

Master Q · Joined: 08 Jul 2006 Posts: 10 Location: Near Edinburgh

Cheers for the thoughts guys; much appreciated.

The car won't be going anywhere 'till this is sorted. Luckily I'm sure I have a 36mm socket so will check the nut first. Likewise greasing things up and maybe re-lining those brakes is a good idea while I'm in there.

Smoothie, not too sure about the tyre thing.. Surely the noise would be constant if something was just fouling? This is very much a load-dependant noise. Eerily though you''re suggestion of the problem being on the left hand side of the car tallys with what I think I'm hearing... So armed with that snipped I'll examine the tyres extra carefully.

This is a kind of 'rolling restoration' and I HAD been using the car as my daily driver. But she keeps throwing up odd faults which are kinda fun to work on and satisfying to repair. Fun and satisfying that is unless it's hissing down with rain and you need to get to a job at 5am! ...Thinking about getting a Freelander to see me over the winter and using the 924 just for fun/backup.