clutch install, won't disengage

[illdrift]

dnegative - This is with the car on the ground

allencr - With the alignment tool, I could turn the discs before I tightened the cover. Was a bit difficult to pull out after everythings tightened.

I went and put a washer behind each of the bolts, to space out that diaphragm cover, and see what would happen. I think you're right about one or both of the discs being run out. If i rev up the engine, it's much easier to select gears, presumably the centrifugal force is straightening the discs somewhat. Especially reverse, that's the worst gear to select, but if I rev >3000rpm it's much easier.

Also, as I take my foot off the clutch pedal, at a low rpm, the clutch kind of shudders as it grips. The washers are stopping it from locking completely, the clutch mostly slips with the washers in.



Is it possible to get the run out fixed?

[allencr]

...I could turn the discs before I tightened the cover.
OK, assuming then that the bearing isn't seized and its inner race isn't binding on the trans shaft. If the shaft friction welds itself to the bearing, it's a bitch to remove.
If i rev up the engine, it's much easier to select gears, presumably the centrifugal force is straightening the discs somewhat.
NO. The disks are not rotating when the clutch is disengaged/pedal on the floor and not dragging on the pressure plate & flywheel. Yours just drags easier when it slips & gets heated up.
Is it possible to get the run out fixed?
Yes. Hit it. High spot, low spot whatever to straighten it out so it'll spin true as possible. Mallet, hammer, palm, block of wood, whatever

Good luck.

[andrew_mx83]

- With the alignment tool, I could turn the discs before I tightened the cover. Was a bit difficult to pull out after everythings tightened.

That may be a clue, the alignment tool should slide in and out freely still once everything is torqued up.
Sounds like it may not be getting pulled up squarely, are you doing the bolts up in an alternating pattern over a few passes?

[lexsmaz]

As Andrew said it sounds like there is definitely an issue there, I would be pulling the clutch out again & spinning the clutch plates on a mandrel or on the input shaft spline & see how they run for trueness & If they look good take the clutch diaphragm to a good clutch place & get them to check it out, as the fault probably lies there ..

[illdrift]

Finally pulled the gearbox yet again.

Engine side clutch disc looks alright, but pressure plate side clutch disc has a mad warp in it, a big high/low side. Probably be 2-3mm out on the high side when the discs are slid next to each other on the spline.

Thank god for progress and thanks for the help

edit:

any tips for getting the gearbox in with minimal damage?

[allencr]

Before tightening it down, with the disks still free to slide a bit, move the alignment tool up & down and side to side, to make sure it's centered & stays there when tightening PP down the rest of the way. If tool doesn't slide out freely, try it again.
In gear so turning the main shaft can line up the splines quickly.
Some have recommended using slotted bolts(heads cut off) in the block for alignment.

[illdrift]

Used a hammer and wood to straighten the disc. Sanded the spline ring on one of the discs which was a little tight. Put the clutch together, the alignment tool slid out a lot easier this time. Cut off some bolts to use for alignment (good idea!). Used a jack this time to hold the height of the gbox steady and slide n (was using some props to hold it near height before).


Went for a test drive and.....

It works! Can easily select gears at a standstill


Thanks again for all the advice, didn't realize how easily those clutch discs can be bent (didn't take much force to straighten them)