My 1997 cinq sporting blew its clutch for the 5th time in 14 months. The problem seems to be that the throwout bearing doesnt remove itself from the spring plate when the clutch pedal is released. The result is that the bearing overheats, shatters, and the debris then enters the clutch and tears it apart. As far as I can see, there is nothing in the construction to keep the bearing away from the pressure plate. How is this supposed to happen?

The bearing should be fitted into the fork, not just resting against it.

D

It is, it has that certain click when its in there correct. The last time it happened, I changed the clutchfork and the 2 bushes around it, hoping that it would solve the problem. It didnt. Do you have any knowledge about what is supposed to keep the bearing away from the pressure plate?

The clutch return spring holds it away if its clicked properly into the fork.

D

Where is the clutch return spring located? I dont see anything that will do its job anywhere, could very well be the source of the problem.

In the RHD market its on the pedal, and the rubber boot keeps the lever on the box back.

D

Here's the ePer image for an LHD Cinq clutch release mechanism.



My guess is number 24 on that image (p/n : 4249840) is what's missing but I'm no expert as it's the only thing listed as "spring".

So basically the cable does the job of pulling the bearing away from the pressureplate?
Nr 24 is still there, but nr 16 might not be. I will take it apart the next 2 days, we will see.

Cars with roller bearing type clutch release will hold tension on the am to keep the bearing in contact with the spring, old carbon pad type thrust bearings work the other way around pulling the release arm away from the spring to give clearance.

Is the sleeve/bush that the bearing slides on still straight? I have seen those bend causing a side load on the bearing.

Shining the release form to keep the bearing dress centre helps with longevity too

The bearing will contact the pressure plate lightly all the time, but there should be no pressure. Your failures suggest the bearing is exerting pressure all the time.

A common issue is the release arm pivot bushes, but I think you've done them.

As said above, the bearing slides on the nose of the gearbox and this can also wear, allowing the bearing to tilt slightly, and not return freely. So check this carefully. Do not lubricate it with anything oily/greasy as it will collect clutch dust and help it to seize. If necessary, rub it with a very soft pencil, as the graphite will lubricate well and not collect dust. You might find a graphite spray as an alternative to a builder's pencil.

Clutch cable might be tight, restricting the bearing return? Check cable, and all those pivots in the linkage.

On RHD cars there have been a few reports of the brake and clutch pedal sharing the same shaft, and the pedal gets tight, so when the brake is applied, some pressure is exerted on the clutch. This also can work the other way, applying the brakes when the clutch is operated.

Last option is a misalignment of engine to gearbox. Any misalignment will cause the bearing to act eccentrically, giving it a very hard time and a very short life.
The gearbox is located onto the engine with dowels.
Check the engine backplate to ensure it is not bent or cracked.
Check the dowel locations, the dowels need to protrude enough to do their job. They can get pushed into the backplate or gearbox and no longer locate properly.
The dowels can also cut oval holes if the gearbox has been forced together carelessly at any time in the past.

Good luck.