13 replies to this topic

[deanmoke]

Moke
1980

I have just fitted a rebuilt 998 engine which has a brand new clutch. I'm having trouble getting into gears intermittently though. I'm using all the clutch hydraulics and actuating parts from my old engine (there wasn't a problem on the old engine). I can easily select gears for most of the time but every now and then, I can't select any gear at all and only achieve in crunching the gears instead. The gearbox wasn't from the old engine and has an unknown history so I don't know if this is a clutch or box issue.
Any suggestions?
Thanks,
Dean

[Ethel]

Try pumping the clutch when it plays up.

Is there no discernible pattern, only happens when warm or cold, for example?

Unlikely to be the gearbox if it's all gears, clutch or primary gear most likely. Hydraulics favourite: even if they were fine before a new clutch might be that bit stronger and it's likely the slave cylinder piston is operating further up or down the cylinder.

[Guess-Works.com]

I'd favour the clutch to be the cause...

If it's crunching into gear, all gears, try reverse as well.... crunching into reverse usually indicates a clutch issue, in that it's not fully disengaging, this could be down to a problem with the clutch installation, worn out plate, rods or hydraulic system...

[deanmoke]

I'd favour the clutch to be the cause...

If it's crunching into gear, all gears, try reverse as well.... crunching into reverse usually indicates a clutch issue, in that it's not fully disengaging, this could be down to a problem with the clutch installation, worn out plate, rods or hydraulic system...

Thanks for all your suggestions.
It happens at all times, cold and warm. Clutch plate is brand new.
I was suspecting the hydraulics myself and have ordered a new slave and also a new actuating arm and associated clevis pins. I also have a second hand master that I will fit if the other parts don't fix it.
I will let you know how it goes.
Thanks,
Dean

[deanmoke]

Right, I have now replaced with brand new parts from Mini Spares.

Clutch master
Clevis pin connecting master to pedal (there was loads of play on the old one and it was a bugger to get out)
All pipework/hose to slave cylinder,
Slave cylinder.
Return spring and attaching clips
Throw on push rod
Throw on arm
Both clevis pins on arm.
Have bled out system with new fluid.

I adjust the return stop and throw on as per Haynes manual instructions. Can't get into gear, just crunching when I try.
When I bring the return stop out by a few turns, I begin to see an improvement and can now select some gears (bite is on the floor and when I select reverse the car begins to move without lifting the clutch pedal). Another couple of turns of the return stop and it's starting to look normal but (judging by the noises) the release bearing is now in contact with the clutch.
What is going on here? I'm lost for ideas.
Dean

[deanmoke]

PS: I've got a pushrod in my parts bin that has been extended by about a centimetre. Will fitting that help me out at all?
Thanks,
Dean

[ado15]

PS: I've got a pushrod in my parts bin that has been extended by about a centimetre. Will fitting that help me out at all?
Thanks,
Dean

This is a bodge fix that shouldn't be needed of all the other parts are in good condition. It tends to be a fix for when the release arm is either bent or worn. With all the replaced parts the longer one should never be needed.

From your description, it suggests there is insufficient travel to release the friction plate. Since you have replaced all the external parts, the only things left are the plunger and release bearing.

Daft question, but you did fit the friction plate the right way round?

Edited by ado15, 29 September 2010 - 09:59 AM.

[Ethel]

It's pre verto then?

Wind the throw out stop fully out and set the return stop. Bother about readjusting the throw out if and whe you get the clutch working.

[ado15]

Another thought (take advantage, I don't do it often!)....

I assume all the parts are the same type? i.e. all Verto or all Pre-Verto?

[deanmoke]

All pre-Verto parts have been fitted.
I have tried backing off the throw out stop so that it doesn't bottom out on the casing but it doesn't make a difference.
Plunger was not replaced but looked fairly new. Release bearing was replaced along with the clutch.
Clutch plate. I don't think so but I've run out of ideas and taking a closer look at the clutch will be next on my list if I can't find anything else (can they be fitted the wrong way round?)
Dean

[ado15]

I don't think so but I've run out of ideas and taking a closer look at the clutch will be next on my list if I can't find anything else (can they be fitted the wrong way round?)
Dean

I don't know, but as you say, ideas are running thin!

Was the friction plate sliding freely on the primary gear spline? If this was sticky for some reason, it could cause it to drag. I've never come across this, but you never know.

[bmcecosse]

Set the stop to a 10 thou gap - with the arm held back by 'hand pressure'. You may indeed need the extended rod - would only take seconds to try it! We often had to 'bend' the arm to get good clutch action on pre-verto clutches. The extended arm is just another way.

Edited by bmcecosse, 29 September 2010 - 01:30 PM.

[ado15]

You may indeed need the extended rod - would only take seconds to try it! We often had to 'bend' the arm to get good clutch action on pre-verto clutches. The extended arm is just another way.

But this would only be because the ball at the bottom of the arm and the plunger it sits in were worn. With all good components, this is not necessary.

[pogie]

Are the flywheel or crank new to each other? I had an issue with a new crank and flywheel that gave the same symptoms as you are having. On fitting the new flywheel it moved too far up the crank taper and ended up touching the C washer of the primary gear thrust ring which in turn was causing the primary gear to become clamped to the crank.

To test this you need to remove the starter motor and observe the flywheel and back plate through the starter motor hole while an assistant presses the clutch peddle. If the clutch system is ok, you will see the back plate move away from the flywheel and clutch plate.

To test if the primary gear is clamped, with the clutch pedal still depressed you need to try to spin the clutch plate (you may need to use a screwdriver to push on the plate as it's difficult to do with fingers alone). If the clutch plate does not move round but can be wobbled from side to side, the primary gear is clamped and you will need to get 10-15thou machined off the recess in the middle of the back of the flywheel where the C washer sits to give it enough clearance.

HTH