Clutch problem?

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Discussion

Bonce

Original Poster:

4,339 posts

286 months

Wednesday 15th January 2003
quotequote all
Enjoyed a nice roof off blat to work this morning but something strange happened when I joined a dual carriageway. I accelerated hard through the gears up to about 105 at which point I backed off because I noticed that the revs appeared to be increasing a lot faster than my speed.
This happened once before about a month ago, also after changing into fifth at just over the ton.

I could not reproduce the effect but the only explanation that I can think of (other than my mind playing tricks) is that the clutch must be slipping. But I've not noticed anything like this happen in any other gear.

Can anyone shed some light on this please?

P.S. It's an S1 111S

Felix7

464 posts

267 months

Wednesday 15th January 2003
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Running on all cylinders?

Bonce

Original Poster:

4,339 posts

286 months

Wednesday 15th January 2003
quotequote all
Hmmm, would that cause the symptoms I saw? It wasn't a sudden change in revs, it was just that the revs were nearing 6000 a lot quicker than I would expect to happen in fifth gear.

Anyway, it didn't sound odd or feel lumpy and the misfire light didn't come on...

Gargamel

15,215 posts

268 months

Wednesday 15th January 2003
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try changing into top when at about 25mph or 30 ish
then accelerate hard - if the car picks up as expected then its not a clutch slippage problem afaik.



other than that i can't explain it

Felix7

464 posts

267 months

Wednesday 15th January 2003
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Bonce said: Hmmm, would that cause the symptoms I saw? It wasn't a sudden change in revs, it was just that the revs were nearing 6000 a lot quicker than I would expect to happen in fifth gear.

Anyway, it didn't sound odd or feel lumpy and the misfire light didn't come on...


Not sure old chap, I broke a spring, which then dropped a valve on the M4, and didn't notice the chnage until I slowed down in the traffic approaching the M25, initially I thought is was damp causing the misfire.

It did rev higher as it was only on 3 cylinders + the misfire light did not come on, however, it did sound a lot rougher, so this may not be the cause in your case.

Maybe a sticking clutch cable? and for god sakes don't go to Strattons, they charged me the earth when inspecting the head.

stove

29 posts

273 months

Wednesday 15th January 2003
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Sounds like the clutch to me. I had exactly the same symptons in my old turbo mini. the first three gears were fine, but when flooring it in top it accerated fine unitl it reched the high torque area of the reve range (about 3500 for the turbo) and it slipped. With the VVC unit I think max torque is around the 4500 rpm mark - is this where it slips the most?

It wouldnt be a misfire. The engine is effectivley mechanically attached to the wheels - the only beark in that link is the clutch friction plates. This is the only way the engine revs could increase independently of road speed.

Check the pedal for full return and also the lever arm. Clutches are self adjusting over time, so either that mechansim has siezed or your clutch plate has had it. With it being just the clutch unit, i wouldnt bother with a lotus dealer. Try Rover instead and maybe ring a get a quote for an MGF beforehand to see if there is any difference in price. There probably will be given you'll pull up in the Lotus...

Good Luck : )

fergusd

1,247 posts

277 months

Wednesday 15th January 2003
quotequote all
At that speed, in that gear, you're basically geting to maximum torque (contrary to popular belief) on the clutch, so IMHO your clutch is slipping . . .

Too many traffic light grand prix starts ?

You'd want to check that the clutch operating mechanism is functioning correctly (master cylinder and slave cylinder not binding, release springs working), that the release bearing is free to move on the input shaft, if all that is cool, then it's gearbox out time for a new clutch.

These things are easy enough to do yourself, if you need some pointers, ask.

Fd

Bonce

Original Poster:

4,339 posts

286 months

Thursday 16th January 2003
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Thanks guys.

GargamelL: I've tried stomping on the gas in fourth and fifth at 30 - 40mph and there's no sign of slippage, it just accellerates normally, even when the engine comes on song at higher revs.

Felix: I sincerely hope it's nothing like the very expensive problems you had!

stove/fergus: I think you're right, it's warning signs of a problem. Mileage is 22k and I never dump the clutch at traffic lights or at any time - but once the car is rolling I do accellerate hard. I would have thought (hoped) that the clutch was up to that kind of use!

So it's time to check the clutch operating mechanism as you both suggest. I would need some pointers on this though please. I know where things are and I have a service manual but am a bit lost as where to begin really!

fergusd

1,247 posts

277 months

Thursday 16th January 2003
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Personally I'd err away from it being a hydraulic problem, but you do need to check.

To check the release bearing is free to move . . .

As with most Elise jobs, get yourself some unfeasably strong, long, thin and flexible arms

Look at the top of the gearbox, you'll see the clutch operating lever coming out of the top and connecting to the clutch slave cylinder, you should be able to move this lever so that the slave cylinder piston retracts into the cylinder, it may be quite difficult (mainly because of access and leverage), but not impossible, you're pushing against a small spring in the slave cylinder and pumpung hydraulic fluid back through the clutch pipe, so no big deal.

www.elise-faq.info/content/gearbox/images/clutchrelease.jpg

The release bearing sits around the gearbox input shaft (the shaft runs through the center of the bearing), presuming you can move this then it isn't stuck.

If you cannot move this then either, the slave cylinder is seized or the operating lever/release bearing are seized, if the former (you can tell by removing the split pin holding the slave cylinder onto the arm and moving the slave cylinder independantly) then it's a simple job to replace, if the latter then you may still need the gearbox out, although it's possible the operating arm has seized in the plastic bush in the gearbox, you could probably loosen that.

If all is working at the rear I'd expect the master cylinder is fine, ie. not too much preload from the pedal.

If all is working at the rear . . . I think the only candidate left is the clutch.

You don't have any oil leaks do you, around the bottom of the bellhousing ? If so you may have oil on the clutch, which can cause slippage . . .

It's just that your descrption of your driving suggests you're not a clutch masher, and I'd be very surprised if you've worn out the clutch in 22K . . . I've done 37K and I do not treat the car with much sympathy . . . and the clutch is, although no longer silky smooth, fine . . .

What year is the car ?

Fd

>> Edited by fergusd on Thursday 16th January 21:16

Bonce

Original Poster:

4,339 posts

286 months

Friday 17th January 2003
quotequote all
Fergus, thanks for the advice, that's fantastic. I'll investigate this weekend.

The car was built in 1999. The previous owner only did 4000 miles and there was no evidence that he abused the car in any way. I had a minor oil leak from the top of the engine last year so oil could have got into the clutch I suppose...