New 4 speed - clutch slipping

[jjames]

just pulled the transmission - everything looks fine.


The throwout bearing doesnt have any wear on any surface (as I would guess it would if there was contact with the retainer bearing).

I test fitted a short type TO as well - it wont work - so the long style is the type needed.


As for the installation of the TO bearing, guess I could use the training on that - when i removed the old one, i just installed the new one by aligning it on the fork and then sliding the input shaft and transmission back into the bell housing.

[Wrenchbender Ret]

I wanted you to look up in side before you pulled it to see if the bearing was backed up against the bell housing.
There are 2 kinds of diaphragm type clutches used. The older model has the fingers parallel with the disc & flywheel. It uses the long TO brg. The later model often used as a replacement has the fingers extended rearward & are about even with the outer surface of the pressure plate, commonly called a beehive clutch. It uses the short brg. There is hardly any way you could have gotten it in wrong. The brg. slides on the trns brg. retainer. The fork goes in the grooves. Some brgs have a lump or pin to keep it from turning.

[jjames]

Well i think have it figured out (thanks for the suggestions!)


I put it all back together again with the long bearing and then did just what you suggested. From underneath I checked the play between the bearing and the pressure plate (its the type that has the fingers angled towards the rear).

Once you tighten the transmission down, the retainer bearing presses the throwout bearing against the pressure plate. The book (factory manual) mentions that you need 1/16th to 1/8th play between the plate and the bearing.

In my case I have none and it would seem that the bearing is being pressed hard enough to engage the clutch (hence the slipping).


So, now my question is, what can i do?

Option 1 - This is a new transmission (M20), i guess the retainer bearing is just a little thicker than the 3speed i had. - Can I change the retainer bearing to a thinner one?

Option 2 - I already tried using the short type bearing, its too short (at least with the current fork and fork ball that I have) - Can I get a different clutch fork, fork ball and shorter type bearing?

Option 3 - Is there some sort of adapter or spacer plate to move the transmission back a little?

Option 4? - ???

[raycow]

The bent finger pressure plate is supposed to be used with a short bearing. I have no clue how you got that setup to work with the old transmission. Even more mystifying is why it worked with the old transmission and not the new one.

You don't have any choice on forks, but there is an aftermarket ball stud made for dealing with problems like this. I think McLeod might have it. If you don't have any luck finding the ball stud, you might want to see if the bearing retainer has enough material so it can be machined to clear the throwout bearing.

Also, you may have another problem that hasn't presented itself yet. What year is your bellhousing?

Ray

[jjames]

The bell housing is stock - '71 3speed with an inline 6. (I think1)

Last owner put in a new (not so mild) 350 - but left the 3 speed.