Clutch starting to slip?

[vit4]

Unusual one, and a bit of a long post I'm afraid! A few things have started to occur in the Astra over the last few days.


The first is very hard to describe as it is fairly intermittent, but when using moderate acceleration from low revs (eg in 3rd at about 25) there is a very subtle juddery sound/feel. Vibration. The revs don't raise and drop again, but it sounds like they raise quicker and then stay more constant; still raising but much slower, despite the rate of acceleration being the same. I don't have a rev counter so cannot say exactly how many revs. It sounds like an automatic almost? This is intermittent without too much pattern, although I think seems to only happen within about 10 minutes of the engine being started.

Also, it seems to be wheelspinning under acceleration (eg turning onto a NSL from T junction) for longer (from just a quick screech as pulling off to actually spinning for a good few yards). I don't think I've changed my driving style, but this is regular now.

I have very limited mechanical knowledge, but would this first symptom be something to do with the clutch, possibly it starting to slip? The car's recently had a service and MOT, so I would've thought that if it was then the garage would have picked up on the clutch not having much life left? The wheelspinning thing I am open to believe that it is just me, or possibly tyres wearing down (although there is plenty of tread left on them :scratchchin), but if it could be related to the first symptom I described I thought I should mention it for the benefit of PH's fountain of wisdom

If anyone can give any ideas I'd be very grateful cheers

[Gad-Westy]

I doubt the two are linked. Your first problem definitely sounds like a slipping clutch. Its unlikely a garage could pick up on this until it starts to actually slip.

Second issue. Could be a number of things. Tyre pressure. Tyre tread. Something picked up on one the tyres.

[vit4]

Gad-Westy said:

I doubt the two are linked. Your first problem definitely sounds like a slipping clutch. Its unlikely a garage could pick up on this until it starts to actually slip.

Second issue. Could be a number of things. Tyre pressure. Tyre tread. Something picked up on one the tyres.

bks Regarding getting that sorted, would I be best sticking to my garage (indy, very good work and good prices) or going to a clutch specialist?


I'll check the tyres over later Cheers.

[Percy Flage]

The wheel spin could be the time of year and damp roads.

[The Wookie]

It's easier to detect clutch slip in higher gears as the clutch sees the same torque as it does in the lower gears, but there's less engine speed change that might hide some of the slipping or make the duration shorter as it's sitting at peak torque for a shorter period of time, so the best thing to do to determine if it's slipping is to stick it in 4th at peak torque (about 3500rpm if it's a petrol), and put your foot flat to the floor. If the engine note flares, your clutch is knackered.

If your clutch is on the way out, then it might be noticeable as 'lazy' gear shifts in the higher gears, i.e. 4th to 5th going up a motorway slip road with some gusto starts to become slurred, even when your foot is completely off the clutch.

If your clutch is really caned, you might even be able to select a high gear with the handbrake on at a standstill if you slowly bring up the pedal.

[HellDiver]

vit4 said:

The first is very hard to describe as it is fairly intermittent, but when using moderate acceleration from low revs (eg in 3rd at about 25) there is a very subtle juddery sound/feel. Vibration. The revs don't raise and drop again, but it sounds like they raise quicker and then stay more constant; still raising but much slower, despite the rate of acceleration being the same. I don't have a rev counter so cannot say exactly how many revs. It sounds like an automatic almost? This is intermittent without too much pattern, although I think seems to only happen within about 10 minutes of the engine being started.

Exact symptoms I had on my Mondeo. Clutch was slipping due to oil contamination from the failed slave cylinder.

[vit4]

The Wookie said:

It's easier to detect clutch slip in higher gears as the clutch sees the same torque as it does in the lower gears, but there's less engine speed change that might hide some of the slipping or make the duration shorter as it's sitting at peak torque for a shorter period of time, so the best thing to do to determine if it's slipping is to stick it in 4th at peak torque (about 3500rpm if it's a petrol), and put your foot flat to the floor. If the engine note flares, your clutch is knackered.

I'll try this now, cheers. Kinda what I feared so I'd better get it sorted.

If I drove it for a few weeks as it is while I get the money together, would any damage be done? Have access to another car so not a problem if it would.

[The Wookie]

vit4 said:

If I drove it for a few weeks as it is while I get the money together, would any damage be done? Have access to another car so not a problem if it would.

I know a chap that drove his Volvo 440 for about a year with a slipping clutch until it finally gave way on a dual carriageway,

However, be warned, the longer you leave it, the more chance there is of the plate wearing through and damaging the flywheel, requiring it to be skimmed or replaced which would be a significant extra cost. Although I believe on some cars, this can happen pretty much as soon as it starts slipping.

If it is because of oil contamination as mentioned, you're unlikely to suffer that sort of damage, however you do run the risk of whatever the source of the leak is progressing to a larger fault leaving you stranded.

Personally I'd park it up and use another car.