Clutch Adjustment T25.

[T3TE]

I have got an '81 2WD diesel bus which was slipping clutch while being driven so I replaced the set but even now it starts to move when the clutch is almost fully released which I hate.

I want it to start moving when clutch is released just a little. I looked for adjustments in the master and the slave cylinders but didn't find any. Please share how can the clutch be adjusted in these vehicles.

Cheers!

[Ian Hulley]

There is a tiny bit of adjustment on the plunger rod in the master cylinder apparently, to take up the slack so to speak ... I didn't notice it on my '89 petrol though (?) .

Ian.

[California Dreamin]

It's been a long time since I've looked at one of these but as Ian has said I also thought the plunger rod had a threaded section with lock nut for 'fine clearance' adjustment.
Basically, there should be a small amount of cleance between the rod and master cylinder plunger to ensure the plunger piston can 'FULLY' return to it's resting position and IS NOT effectively being propt open (partially depressed) when the pedal is fully released.

Martin

[T3TE]

Right I will check the MC..... I have a old slace cylinder although it is rusted pretty badly but the rod seems to have threads on it with a lock nut... wouldn't that be for adjustment?

Thanks.

[Aidan]

your slave cylinder doesn't sound original - a photo of it would help, there is no adjustment in a T3 slave cylinder and the pushrods from the two different designs are not interchangeable
a new slave is around £40 from gsf or brickwerks
there should only be 1/2mm of free play at the pushrod at the master cylinder and adjustment is an a*** of a job - usually it's slack due to wear in the pedal/clevis set up, ovalised hole in the pedal/sloppy pin and loose action, which really is refurbished pedal set time

[ajsimmo]

When you had the box out to do the clutch, did you check the cross-shaft in the bellhousing was moving freely?
Could be partially seized and tight, just holding the clutch release bearing under slight pressure, hence the old clutch slipping. New one (with a bit more meat on it to fill the sandwich) clamps up ok but only needs a small amount of pedal pressure to release. If this is the cause, it won't be long before new clutch starts slipping. The fitter should have noticed it when fitting the new release bearing (assuming it's had a new one), but still worth a mention...
Be worth dropping the slave off and working the arm by hand to check it's moving freely.

[T3TE]

I will take a picture and post it here...

I did check the cross shaft my self at the time of replacing the clutch and it was moving freely.

I discussed it with a very experienced vw mechanic and he says if I shorten the length of the rod of the slave cylinder I will be able to achieve what I am looking for which is that the car should start moving right when I release the clutch even a little bit. Alternatively, He says to replace the two 13mm bolts that hold the slave in place with longer ones and put washers/spacers between the plate and the cylinder and it will have the same effect as shortening the rod.

Just a little back ground... since I have toyota 3C-TE motor, I have a 2L/3L Toyota clutch disc, pressure plate and a Toyota release bearing which is welded onto a dead VW release bearing... the input shaft has been extended to accommodate the adapter plate and splines replaced with Toyota ones.

[kevtherev]

Why on earth didn't you reveal this piece of information in the first post?

[T3TE]

Hmmm... probably because it has been about three years now and I did not have such problems with my first clutch set. The adjustment issue has come up after replacing the set.

[T3TE]

Please find the old slave cylinder rod pictures attached.


It appears as if rod has been extended for some reason; I have not been using this cylinder. I replaced it with a new standard one two years ago. I just took it out of my old parts since I was considering replacing my newer rod with this older longer one but the specialist mechanic says that I need to shorten the rod and not extend it.

Please advise.

[Aidan]

a longer pushrod will give you quicker throw and hence better disengagement
when it comes time for a new clutch release fork (crossshaft) get a RJES VW pattern one as that has extra splines for cast arm so you can add an extra 15% into the equation easily, ditto if you have a diesel arm, fitting a petrol arm will give you extra 15% throw

[ajsimmo]

I have a 2L/3L Toyota clutch disc, pressure plate and a Toyota release bearing which is welded onto a dead VW release bearing... the input shaft has been extended to accommodate the adapter plate and splines replaced with Toyota ones.

Why on earth didn't you reveal this piece of information in the first post?

^^^WHS^^^

Slave pushrod length is now almost irrelevant, as it depends on the space between the two halves of the Heath Robinson release bearing. Last one I saw done like this (2.8 Ford V6 bodge) had lasted less than 100 miles before being recovered to me to be fixed. Had ruined the bellhousing oil thrower, seal and input shaft tube, sheared the badly welded tube between the two bits of release bearing, and spun/destroyed the spigot bearing. Best fix was throw it all away and return to standard DG setup, then LPG to recoup the cost. Drove lovely from then on.