engine and drivetrain Clutch Wont Disengage - 5Spd Swap

[GoFaSSter]

Try the measurement as suggested. That should give some clues. I would also have your trusty assistant do the old pedal push bleed as well. Keep in mind you may be moving bubbles all the way from the master so you will need to pass a good amount of fluid - so to speak. Just because it works off the car doesn't mean it will push the arm.

Perhaps the wrong TO bearing came in the right box.

I faintly recall something about changing the tip on the rod.

I may have missed the answer, but did you do the measurement? It will help you to see if the slave cylinder is even engaging the arm.

[M3M3]

I may have missed the answer, but did you do the measurement? It will help you to see if the slave cylinder is even engaging the arm.

see post #29....

[GoFaSSter]

see post #29....

Dang it! Gotta get glasses...

[M3M3]

Dang it! Gotta get glasses...

i could loan you some of my spare tri-focals....

[Hans]

So you're saying that the arm is one inch in, and slave rod would have 1 1/2" of travel (2 1/2" total)?

[Hans]

Haynes suggests removing the cyl after bleeding and the pushing the rod back in all the way and release slowly. It also talks about pushing a blade between the cyl and the bell housing to scrape the rod as it extends to verify amount of travel (i.e., read length of scrape on rod.) It should move at least 20mm.

[NickVyse]

Been through this recently with my NK - turned out to be a dodgy pressure plate that didn't have enough travel to allow the disk to disengage. Mate had the same in the UK and Jaymic now only sell recon units due to too many returns. 

 

There was a suggestion of manufacturers using a combo of later BMW plates and disks that they believed worked for an 02, but this is just heresay. I'll try and get a pic of the dodgy pressure plate if I didn't throw it down the mountain in a fit of rage. 

[thehackmechanic]

On the assumption that human beings are not that different from each other and experience similar problems,  I just searched this forum for "5-speed clutch won't disengage" and found posts that traced the problem to (in decreasing order of frequency):

 

--wrong throwout bearing

--throwout bearing not correctly oriented on lever arm (flat tabs on throwout bearing should rest on the lever arm)

--clutch disc installed backwards

--disc sticking to the flywheel from sitting for a long time in a humid environment

 

So, if you've verified to your satisfaction that it's not a hydraulic issue (air in the line), and that the slave piston is extending and retracting, I agree with Marshall: Man up and yank the bitch. And join the club of this particular misery; I myself once installed a 245 that itself turned out to be bad and had to yank it out and heave it in the recycle pile.

[evanb]

We'll, got a chance to do the scrape test and the slave was moving about 26 mm. So that rules that out. Time to pull the trans.

So I'm looking for a wrong TO bearing, clutch disk installed backwards, mucked up installation of TO bearing/clutch arm/clip.

Could the pressure plate be too tight? I wasn't exact on that front, but only went maybe an eighth of a turn too far on any of the bolts. A few pounds too far.

Anything else to look out for?

[peterschop]

Did you have the flywheel resurfaced? If so, did they machine the shoulder in it?

[evanb]

I'm coming from an auto, so I got the flywheel second hand, and it was resurfaced with to spec, by a member of this board.

[Hans]

Hard to see how a few mm of flywheel would create that much free play. Ditto for plate bolts - although those are bolts that I would want to torque exactly. Maybe time to replace? And don't forget to tighten those in stages; I use a diagonal pattern to snug down evenly.

Somewhere in FAQ archives as I recall are dimensions for TO bearings.

 

We wait with bated breath. Maybe you should video the final opening of the mystery chest...err... bell housing.

[peterschop]

The flywheel should have a shoulder machined in of .015", that is where the pressure plate sits. If not put in, it would cause the clutch to slip. If too deep, it may not release. Just something to check when you remove the transmission and clutch.

[thehackmechanic]

DUDE, DISH!! WE'RE DYING TO KNOW!!

[evanb]

Haha sorry guys I've got the trans ready to come out but I have been unable to yank it myself. I'm hoping my dad we be able to give me a hand Wednesday, so I should be able to update then (with as many pictures as I can).