Discussion
For several weeks now I have noticed that when taking off in a spirited manner there was instantly a faint hot almost burning smell.
I think I have just detected some clutch slip (by hard acceleration in 3rd), but its not easy to tell as I cant go ragging it around on my normal journey.
A) What is a good test method ?
B) If it has just started slipping, can it wait until Autumn or it will score up the fly wheel within days ? I know it depends how I drive etc, but I guess what I need to know is, when it starts slipping is it already on the rivets, or is it just causued by reduced thickness of the friction plate.
I think I have just detected some clutch slip (by hard acceleration in 3rd), but its not easy to tell as I cant go ragging it around on my normal journey.
A) What is a good test method ?
B) If it has just started slipping, can it wait until Autumn or it will score up the fly wheel within days ? I know it depends how I drive etc, but I guess what I need to know is, when it starts slipping is it already on the rivets, or is it just causued by reduced thickness of the friction plate.
I've always been told to drive along at 20-25mph and then put it in fourth and give it a fair chunk of throttle is a decent way to check for clutch slip (Useful when buying a car)
If its only slipping in certain conditions, as long as you drive the car around those conditions it should be ok, but it'll get worse as time goes on. I've had clutches slip and when removed from the car there was a couple of mill between the friction surface and the rivets.
Thanks
Matt
If its only slipping in certain conditions, as long as you drive the car around those conditions it should be ok, but it'll get worse as time goes on. I've had clutches slip and when removed from the car there was a couple of mill between the friction surface and the rivets.
Thanks
Matt
Edited by StreetDragster on Wednesday 11th June 08:53
Yes, I thought I remembered changing clutches back in my youth and there was still some thickness left before the rivets touched. I suppose as the friction plate gets thinner the spring is applying less force, so less grip.
I tried accelerating hard from tickover in top, but it just gradualy increased speed. (not enough torque to make the clutch slip)
Have you had to replace a clutch on the Chim, if yes what where the symptons that you first noticed ?
I tried accelerating hard from tickover in top, but it just gradualy increased speed. (not enough torque to make the clutch slip)
Have you had to replace a clutch on the Chim, if yes what where the symptons that you first noticed ?
Hi, has your car done many miles? My Chim is in as we speak for a gearbox rebuild, partly due to the syncromesh on reverse/5th being worn, but also because I'm experiencing what at first appeared to be a slipping clutch. My Chim has only just done 40k and I took it to Automedon in Blackpool (there's not a much better place to take your car than to the people who put it together in the first place...). Anyway, Dave at Automedon swore that he'd never had to change a clutch on a chim with low mileage before, apparently the main cause of clutch problems is fingers on the pressure plate breaking, rather than wear on the clutch plate itself. My chim was therefore diagnosed with a sticking thrust bearing carrier, which is a cast circular part that fits behind the bearing and sits on the main shaft. On my car this is sticking, which is making the thrust bearing take it's time to return, giving what feels like a slipping clutch. This was diagnosed as it is only slipping in the higher gears, ie 3rd, 4th, 5th, whereas if the clutch plate was worn it would slip all through the gears, particularly 1st and 2nd. Would be worth checking this out, if at all possible with Automedon - they really know their stuff and have given me a great deal of info about my car that will be great to pass on when I come to sell it on... Hope this helps, cheers, Simon
rev-erend said:
If you have the T5 box - there is an inspection plate at the bottom of the bellhousing which can be removed.
Check for oil contamination .. if you have oil in there - it's possible to spray an alchol type oil cleaner in there .. and possibly save the clutch for an early change.
Alan, yes its a T5 box and I have recently fixed a sump leak that had caused a certain amount of oil to get into the bell housing. It didnt look to bad inside, but I suppose it is a possibility that there was some contamination of the friction plates.Check for oil contamination .. if you have oil in there - it's possible to spray an alchol type oil cleaner in there .. and possibly save the clutch for an early change.
You cant tell me what alcohol cleaner you have in mind can you ?
WokingWedger said:
Thanks Simon.
The car has done over 90,000 miles and I cant find any records of it ever having been changed.
I will investigate the broken release finger possibility though.
Hi Peter. I never replaced the clutch, and neither did the previous owner. I too could find no record of it ever having been changed, which means it's done rather well!The car has done over 90,000 miles and I cant find any records of it ever having been changed.
I will investigate the broken release finger possibility though.
WokingWedger said:
rev-erend said:
If you have the T5 box - there is an inspection plate at the bottom of the bellhousing which can be removed.
Check for oil contamination .. if you have oil in there - it's possible to spray an alchol type oil cleaner in there .. and possibly save the clutch for an early change.
Alan, yes its a T5 box and I have recently fixed a sump leak that had caused a certain amount of oil to get into the bell housing. It didnt look to bad inside, but I suppose it is a possibility that there was some contamination of the friction plates.Check for oil contamination .. if you have oil in there - it's possible to spray an alchol type oil cleaner in there .. and possibly save the clutch for an early change.
You cant tell me what alcohol cleaner you have in mind can you ?
It removes oil, dirt etc..
Ideally - get someone to depress the clutch and prise the friction plate away from the diaphram and spray the cleaner in there.. wear safety glasses.. for obvious reasons. It cant make it any worse .. hopefully much better
The practical test is rather hard on the clutch but quite easy to do. Get the car rolling at around 3000 rpm in 4th gear, accelerate hard and as it goes through 3500 rpm or so lightly press and release the clutch, don't fully release it but just enough to let the revs blip upwards. Keep it very short so the revs don't rise much. As you take your foot off the clutch you should feel and hear the revs pulled down very positively. The less positively the revs are pulled down the more marginal the clutch is. In extreme cases you might find the engine can keep the clutch slipping once it's started. This is very very bad for the clutch, so when you do this test just dab the clutch briefly and as soon as you've come off the clutch ease off the power and let things cool down.
ive got similar problems if i try to boot it in or fifth or forth i get clutch slip but if i change down and give torture ie rev limiter in 2nd then hit 3rd rev limiter then 4th it does not slip makes no sense at all and its only 49000 but i dont know if the last owner drove round with foot restng on the pedal if lasts to do roar and bng iwill strip it for and have look
paulin said:
ive got similar problems if i try to boot it in or fifth or forth i get clutch slip but if i change down and give torture ie rev limiter in 2nd then hit 3rd rev limiter then 4th it does not slip makes no sense at all and its only 49000 but i dont know if the last owner drove round with foot restng on the pedal if lasts to do roar and bng iwill strip it for and have look
A lower gear - is actually giving less load .. That's why when people 'test' a clutch - they put it in 4th or 5th going up a big hill and make it labour quite hard.. you can even lean on the brakes a little to see if its slipping but that is being quite animal..
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