Clutch Mystery

[terryp]

Hello
Having started the car, there seems toi be a problem with the clutch which is very strange........

Basically I cannot engage a gear with the engine running, which would indicate either the clutch not actuating or the plate stuck to the fly wheel.
If I start the car up in gear (which I can) the car just very very slightly begins to edge forward but I can brake and the engine doesn't stall. I then let the clutch up and it pulls away and I can feel the bite point. This would indicate that the clutch plate is not stuck and that the clutch is actuating.
The Clutch slave cylinder was old (I fitted new rubbers) but its not leaking. Master Cylinder was new. I assembled the engine / gearbox / clutch in the chassis about 18 months ago

So whats going on???????

Thanks
Terry

[normanjsmith]

Terry

I think your crankshaft bush/bearing is dragging.

Norm

[terryp]

Thanks Norm, is there anything I can do?

Cheers
Terry

[fatboyoz]

Norm,
My Elan's clutch is doing the same thing as Terry's. Could you please elaborate as to which bearing/bush you are referring. Are you referring to the spigot bush in the end of the crankshaft?
Cheers,
Colin.

Terry

I think your crankshaft bush/bearing is dragging.

Norm

[normanjsmith]

Colin

Yes, that's the one. Early cars with a 4 bolt crank had a sintered bush. I think the change to a sealed roller bearing came with the 6 bolt crank.

Norm

[normanjsmith]

Terry

If you're lucky it may come good after some use seeing it hasn't been used for some time. If not, I guess you have no alternative but remove the engine and replace the bearing.

Norm

[terryp]

remove the engine and replace the bearing.Norm

GULP!

[rgh0]

It could also be the clutch plate dragging slightly when the pedal is fully depressed due to air in the system or it just needs adjustment to remove to much free play. If the clutch plate is stuck on the splines it can also drag on the flywheel face when the pressure plate releases

Normally a failing and dragging bush or bearing between the flywheel and input shaft will make a noise you will hear

cheers
Rohan

[terryp]

Rohan
No Noise
If the clutch plate is stuck on the splines , how can I free it up?

Thanks
Terry

[rgh0]

normal driving it should free it up if its stuck on the spline. It also could be a damaged facing on the clutch that has come loose or something wrong in the throw out mechanism inside the bell housing and that is causing the dragging but it would be strange for this to happen just as you were doing slave cylinder repairs.

I would checking its bled ok and the arm is moving fully as you depress the clutch and the adjustment does not have to much free play. I would then drive it and exercise it. If it is still dragging then you really need to pull the engine to find out what's gone wrong inside.

cheers
Rohan

[miked]

Bit of a stab in the dark but seeing there is no noise could it be the 1st gear synchroniser ring worn in the gearbox not doing it's clutch type grip thing (worn out) to allow engagement. Don't know what the pedigree of your gearbox is but is seems like your clutch is doing all the right things when you engage with the engine stopped. Does this make sense? The moving foward bit contradicts but as said could that be incorrect adjustment and low bite point not allowing full clearing.
I say this as I had temporary box in my Plus 2 that had synchro rings worn to hell and I struggled to get it into first gear when stopped. I used to engage 1st while the car was still on the move as I was that bothered about getting it in at traffic lights and failing. When you say engaging a gear do you mean just 1st or 1st and 2nd or all of them.

Or a bit of both, drag and worn ring?
Mike

[terryp]

Thanks Rohan

All the best
Terry

[terryp]

Bit of a stab in the dark but seeing there is no noise could it be the 1st gear synchroniser ring worn in the gearbox not doing it's clutch type grip thing (worn out) to allow engagement. Don't know what the pedigree of your gearbox is but is seems like your clutch is doing all the right things when you engage with the engine stopped. Does this make sense? The moving foward bit contradicts but as said could that be incorrect adjustment and low bite point not allowing full clearing.
I say this as I had temporary box in my Plus 2 that had synchro rings worn to hell and I struggled to get it into first gear when stopped. I used to engage 1st while the car was still on the move as I was that bothered about getting it in at traffic lights and failing. When you say engaging a gear do you mean just 1st or 1st and 2nd or all of them.


Mike

Mike
Any gear! Gearbox is original to the car but the car had only done 32000 miles when it had been laid up in 1986 with a rusty chassis. I've now replaced the chassis , rebuilt everything over a 2.5year period.
I'm a little frustrated with this!

Thanks
Terry

[terryp]

Just tried it again but pumped a bit and pushed as hard as I could into the carpet and was able to engage gear so it looks as if its either air in the system or the slave cylinder.
I'll try again on Sunday when my bleed assistant (wife) is available
Thanks to all
Terry

[alan]

it could also be the bearing knackered on the input shaft of gearbox.
I had this problem many years ago