Transmission noise

The mystery was over when I pulled the gearbox this afternoon.
The contest begins as of now....
A cookie for the person who guesses the
cause of my mystery noise!
One guess per entrant!

I'll guess it was the same thing that happened to Malcolm's car when I was it the UK, the water pump pully was rubbing against the firewall, a broken mount perhaps?

I put a stethoscope on the water pump, first thing. It was fine.
Not the throwout bearing either!



[ April 27, 2003: Message edited by: Bill Bayard ]
Today, I was out for a drive, when out of nowhere, a noise appeared from my engine bay.
It was a mild scraping or grinding sound, happening when I released the clutch, or let off on the gas. Under power and at idle, all sounds normal. The noise appears in all gears, without prejudice. I was NOT driving
the car like a madman either, just loafing down the road, at about 65-70MPH. The noise was not there, the last time that I drove the car. There is no vibration, the engine runs fine, and the clutch appears to be OK.
I am inclined to think that the noise is coming from my throwout bearing. The only other possibility that I can come up with, is the gearbox main shaft bearing.
Anybody have any ideas or comments, before I start tearing things apart?
Thanks for any help that you can offer!

That definitely sounds like all the symptoms of a throw out bearing. Put it in neutral and gently push in and out on the clutch. If it grinds or whines its probably the throw out bearing.
If it is the throwout it should not make noise unless it is turning which should only occur when you push the pedal. It would be possible that the adjustment is allowing the throwout to touch (lightly) all the time.
WE HAVE A WINNER! Congratulations, Eric!

Two springs, and the two closest rivets were

broken. Luckily, the new moving parts did

not cause any further damage!I had expected

this to happen, as I had used a stock

Porsche clutch disc.

Needless to say, I will be ordering a

Centerforce clutch or it's equivalent, later

this morning. Thanks for all the input,




Hi Bill

I have had this problem twice now but never with a noise first, just a clutch that wouldn't work. I put it down to multple launches on 11 inch slicks in competition circumstances. The clucth plate springs rotated 90 degrees and so held the system apart. Eventually I changed to a springless clutch plate and that worked fine for both road and track use. Ok so the clutch was a bit on or off only with not a lot in between but you adapt quickly. With the new Quaife parts in my gearbox I have reverted to the sprung clutch centre but if that fails I will be back to the solid again without concern.

The other thing to check when playing around changing clutch parts is that the lever arm operating the release bearing clears the pressure plate as when I first upgraded my clutch to a higher pressure plate the arm touched the plate ever so slightly. It was soon sorted but a pain none the less. This may be a specific Renault gear box problem but the check should be made for all makes perhaps.


Fortunately, my clutch blew up close to home, and I was able to baby my car back into my garage, with out doing any damage to my flywheel. Unlike your scenario, my springs and rivets stayed put.
I have yet to do any line launches in my car for this very reason. I guess there was still too much torque for the disc to handle.
If I can scrounge enough cash from my car budget, I'll be replacing the entire setup with an aluminum flywheel, aluminum pressure plate, and a MUCH beefier clutch disc. Then I'll only have to worry about axle shafts!
Thanks for the tip on the clutch fork(arm).
I'll keep an eye on that, when I install the new parts.


I think Tilton makes a clutch setup that would work with the G50(two disk). I haven't talked to them about it though. Rick had a high performance clutch from Kennedy that is very tough, but in his car has a tremendous pedal effort.

Sachs makes a Power Clutch kit($459USD)for the G50, which includes an aluminum pressure plate,slotted and much stronger disc, and throwout bearing.(Pelican Auto Parts)
This single disc is still the spring type, so
it should be a good setup for the street,
and occasional track day, without requiring Bigfoot to depress the clutch pedal.

I like chewy Chunks Ahoy. Email me for my address.
. If i remember right I heard an engineer from Honda saying that those rivets are designed to shear at a certain torque to prevent damage to the gearbox in extreme cases of shock, we had alot of them go on the integra type R when dumb kids would race them and shift 1-2, pull to redline then miss 3 and hit 1 again, lots of damage. Not a single person would admit to what they did but it was pretty obvious it was overreved when all the valve heads are sheared off and buried in the cylinder head and there is nothing left of the pressureplate.

[ April 30, 2003: Message edited by: Eric ]
Have you talked to the guys at Renegade Hybrids? They do a lot of V8 to Porsche conversions and I remember somewhere about them using Kevlar in their clutches to solve the problems with the clutches as the regular clutches just can't hold up to all that power. Haven't talked to them in a while.

I've talked to everybody out there, except for Kennedy Engineering. I have had great luck with them in the past, and I will be giving them a call, so that I can make a completely informed dedcision.
The range of discs, PP's, and flywheels that
are available is mind boggling. Prices range from very reasonable, to the ridiculous!
I'll be calling KEP this coming week. I'll
let keep you informed of my findings.

I run a T44 used on all the big block cars. The clutch P/P was a twin disk cast iron arrangement which is unobtainable. The disks are made like a regular disc but without the springs. It is very drivable unlike the multi discs of Tilton or Quarter Master. Mcleod has made their Street Twin in the same way. You can get it with an aluminum or steel flywheel and it runs a 10 inch clutch. It is around 900 dollars. I have just installed it and cannot tell you if it will work as well as they say. They are made in two ways, 500 hp and over 500 hp versions.