924Board.org

doer1316 · Joined: 15 May 2004 Posts: 14

I have a questions. I have a 1978 924 NA.
When it is driven while turning there is a griding noise.
It is extremely strange and very load.
If I push in the clutch it goes away.

I am thinking that it is a problem with the torque tube. What are everyones suggestions?

Ozzie · Posted: Tue Nov 08, 2005 7:53 am Post subject:

Is the noise there while the car is stationary?

When moving is the noise there in gear, neutral, under load or cornering?
Clutch in or out during these times?

More information please.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

doer1316 · Joined: 15 May 2004 Posts: 14

Thanks for the reply.

It only happens when driving and turning.
If I am turning and push the clutch in - it goes away??

Smoothie · Posted: Wed Nov 09, 2005 6:46 am Post subject:

Nothing different happens with the drive shaft and clutch while turning as compared to going straight, so I wouldn't be suspecting those. The CV joints on the rear axles (aka - halfshafts) are a possibility, as well as the rear differential.
What happens if you put it in neutral and let the clutch pedal return back out - and make the same turn at the same speed...do you still get the noise with that?
_________________
"..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

Ozzie · Posted: Wed Nov 09, 2005 7:06 am Post subject:

I suspect either CV joints or wheel bearings as well.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Lizard · Posted: Wed Nov 09, 2005 1:57 pm Post subject:

with cv joints and wheel bearing (more so with CVs) the noise will go away when the clutch is pressed as it isnt under the same load.
_________________
3 928s,

doer1316 · Joined: 15 May 2004 Posts: 14

How can I check the CV joints to make sure they are bad?

I was thinking that it was the torque tube b/c when in a turn (body roll) the torque tube is being stresse causing wore out bearings to vibrate.
I really hope it is NOT the torque tube? Is there anyway to check the torque tube?

The CV joint and wheel bearings seems like a better answer and less expensive than the torque tube idea.

Lizard · Posted: Fri Nov 11, 2005 12:18 pm Post subject:

take out the CV joints and swap ends and sides, as well check to make sure your front wheel bearings are at the proper tension.
swapping the CVs around should take care of them,
and if you check the wheel bearings that should eliminate them as well as they will either cause noise when loose or failing. (front only, rear are not adjustable and simply fail)
_________________
3 928s,

Smoothie · Posted: Sat Nov 12, 2005 2:17 am Post subject:

Just a bit more detail on CV swapping/flipping/rotating/whatever.. First, leave the CVs attached to the half-shafts as they are. Just remove the halfshafts-CVs as assemblies and set them down in the same orientation as they were on the car. (This would be a good time to re-pack them with CV joint grease, so do that, but don't get the orientation mixed-up.) The deal is, you don't want to do both a swap and a flip, you want to do only one or the other. By "swap", I mean move the left halfshaft to the right and the right to the left without flipping. -And by "flip", I mean take a halfshaft and flip it so the side that was on the wheel side is now on the gearbox side. The idea is to reverse the direction of thrust on the CV joints - doing both a flip and a swap will leave you right back where you started - although everything's been moved around, the direction of thrust on each CV will have not changed. -So, either flip or swap and don't do both.
_________________
"..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

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

You guys have forgotten to mention that worn cv joints usually "click", not grind.

Grinding is usually dry wheels bearings.

If the car was mine, I would line up replacement front and rear wheel bearings, grease seals, and (2) 14oz containers or tubes of cv compatible grease (I still like Valvoline Synthetic) put the car of stands, pull the rear axles, inspect and rear pack the cvs if they are still good, then inspect and replace the rear bearings as necessary. Then move to the front and inspect, replace or repck the front wheel bearings as necessary.

In all honesty, servicing wheel bearings is a dirty job, and most cars don't ever get the cv axles or rear wheel bearings serviced on schedule. Not until they are grinding that is. If you have never inspected, and repacked the wheel bearings and cv axles, it's past time for it to be done. If you take care of this, the odds are, you will solve your grinding problem.