Temporary Clutch failure

[desmondo]

At the Palmersport event yesterday I had a nasty experience with what I can only assume is the clutch. Coming off a long straight braking hard down into third, into the bend - coming out of the bend I try and put the power down I hit the redline with no power to the wheels. I then change up into forth to try another gear - powerdown hit the limiter - again no power to the wheels. Put the lever back into neutral dropped the clutch back into third everything is OK again!

Now this isnt the first time it has happened. At York Raceway I did a completely sh1t run where exactly the same thing happened - only it was 2nd and 3rd. At the time I assumed it was the tyres spinning ‘cause I had something on them.

Simon who was at last nights event said this has also happened to him. Has this happened to anyone else? Do I/we have an intermittent fault with my/our clutches or is it just that the 172 clutches are complete sh1t when pushed hard? The thing is that it was OK a couple of seconds later? If it was failing/overheating/something I would have expected it to be stuffed for a period of time – not for just 2 seconds!

 

[Griff]

Sounds like a fault with the Clutch plate to me. Im sure some one else mentioned a common problem with the clutches on the 172 where they can "glaze" over yet minutes later they are fine again.

Griff

 

[ak_uk]

Didnt have that problem but had problems engaging third gear occasionally...




Arjun

 

[desmondo]

The probem is that it was stuffed only for a matter of seconds. Once in nuteral and back again everything was fine. Strange!

Im tempted to take it to Renault - but I reckon theyll have the car for the whole day - test drive it for 30 seconds and say that the car is fine!

 

[Captain Slarty]

des,

you suffered cluth fade by the sound of it.. same as brake fade.. the clutch works on the same principle as the brakes.. ie, friction material against a disk.

it is possible to overheat the clutch linings and 2 events can occur..

1st is glazing of the linings.. although unlikely as it cleared quickly.. second is a high temp gas layer with slight glazing..

if its fine now, dont worry about it to much.

consider an uprated clutch (competition) for your driving style.

Joe

 

[desmondo]

Cheers for the info Joe. Im going to see how it fairs up at the next York meet. Putting in a competition Clutch though is probably gonna cost a lot of wonga.

Engine out job.

 

[Captain Slarty]

Hi Des,
ok, there are a few thngs you can try

its probably more technique really.

use the brakes to slow the car.. ie - dont drop a cog with excessive use of the clutch to slow down and synch the gears, also, try to avoid clutch slip at take off.

the usual culprit is the down change.

Joe

 

[Nick Read]

Clutch fade definitely. In my experience its caused by standing starts (1/4 miling) and harsh downchanges (track & B-road driving).

The clutch hardly gets any cooling at all, unlike the brakes, so it will fade when abused. Even uprated clutches will get this same effect, itll just take a bit longer to happen.

Paddle clutches dont like standing starts either but they will transmit drivetrain shock through to the gearbox and knacker that instead if you do too many standing starts.

When I did in one of my many clutches, it was repeated standing starts (0-60 testing) that did it, followed by a B-road thrash. It was never the same again and used to drive ok until you went for standing starts and would fade straight away.

New clutch time? Or get it under warranty?

 

[desmondo]

Feck - new clutch already? Only done 7.5K. Ive hardly given this one much stick - in fact Im only just getting started. 1 day at York Raceway 6 runs, 1 track day and the usual road driving. I do drive pretty hard sometimes but no more so than anyone else. Put it this way Im not practicing my standing starts of every set of lights. Although maybe I need to given my last drag strip performance!

Anyhow during normal driving I dont think Im especialy hard on the clutch? Also I never down change harshly without trying to match revs & road speed.

Bugger.