4 CLUTCHES changed in 18 months (TOB Melted) 90 240sx

[Peabody]

OK, I do not know what to do. This started after I had a NEW Jasper KA24E installed after my original KA locked up. I am the original owner and have never had any problems with clutches before the new motor.

I had a ACT EXTREME before the motor blew and it was to stiff for me, I have a ruptured disk and have leg issues. SO I had a ACT HD installed with the new motor. It was softer in the beginning but after time was firmer then the extreme. I drove it maybe 600 miles and then it would not go into gear. The TOB was melted onto the teeth and made an indention on the TOB where the teeth of the PP were. The PP was scorched up but the clutch itself was not worn out.

So I tried a Exedy Stage 1 and this thing was much stiffer then the ACT and it make a sound like the reverse sound in any gear and would get louder with higher RPM's. The clutch was also very notchy pressing in or out and got worst with more millage. After maybe 250 miles the clutch assembly came unbolted from the top from the hard force of pushing in the clutch.

Still Idiot me took it to the same shop because they were charging me $200 for the labor. They thought the trans output or maybe input shaft (I FORGOT) could be bad because I would hear a bearing whine when the clutch was out and as I pushed down on it the whine would go away.

After spending $800 for a new 5 speed and installing a RSD clutch everything was fine for about 2 weeks. When I would 1st drive the car in the AM it was fine and after maybe 10 miles the pedal would stiffen up a little and was notchy on release. The odd thing is if I turned the motor off the clutch if light as a feather and as smooth as silk. It only acts up with the motor running. I just drove it and noticed that the time it took to act up went from 10 miles to 8 then 6, ETC. Now it is stiff at 1st start and very notchy, sticky pedal going down and up. It is like you have no control, the clutch is either engaged or not.

I have changed all lines, fork, master & slave at least 2 times and even the Damper that is between the master and slave on 89 and 90 models. Most people bypass this and when I did then the clutches were acting MUCH stiffer and more notchy.

But only with the engine running the pedal is like this. I even can feel the pedal starting to stiff up when I bump the started.

I was thinking maybe the Flywheel is warped! This is the only part not changed. I think the idiots only had it turned 1 or 2 times.

The Jasper engine is under warranty and the Rep said the crank could be a problem and they want to check this with a run out gauge at a different shop. But that shop is very expensive and if the engine is fine then I will have to pay for another clutch job at $100 an hour.

My friend said he would do it for $300 & I could buy a new flywheel and try another RDS clutch. That clutch was great for me, I want a clutch that will catch 2nd but have a soft pedal. It is 15% more clamping over stock. I only have a header, performance Chip, Air Intake and exhaust.

Would a Bad flywheel eat up TOB & make the clutch act like this?

[rioredstang]

It sounds to me like they don't have the push rod in the master cylinder adjusted properly. If the push rod is to long it doesn't allow the compension port to relieve pressure on the TOB keeping rubbing the pressure plate all the time. As the fluid heats up it gets worse. The TOB should have a little free play in it. If not then the clutch arm and pivot may have a problem.Drive the car till it starts to get stiff then check for free play. I have seen the TOB bind on the transmission input shaft also.

[Peabody]

Well I have a new fork and the new transmission has a new pivot. I will check on the free play again, but with all 4 clutches I adjusted the play with the shop manual specs and did not have much freeplay.

This is just driving me CRAZY having to have the clutched looked at again. It might be worth the money to bring it to a Transmission shop because the cost of clutches and the labor is more then the value of the car.

But I do not understand why when I turn off the motor the clutch pedal is smooth and very light. They once the motor is running it acts totally different and is VERY STIFF and not smooth, it feels like it is getting stuck on the release and comes up 1/4 inch at a time, a ratchet feeling, like something is holding it down.

With the engine off it acts fine and starts to bind up with small bumps of the starter. So my FLYWHEEL theory has nothing to do with this?

[Chaotic_Warlord]

So let me get this straight, you have a new rebuilt engine, and new trans, new clutches, and you're stilling having issues. Check your slave and master cylinders, replace the hardlines with a steel braided hose, if you replace all the external parts then I don't know what the problem is.

[Peabody]

I had a steel braided hose made up and also changed the small hose from the Dampner to the slave.

New Master and slaves were changed 2 times.

Yes everything is NEW but the FLYWHEEL.

The clutches are fine for a few weeks and then get stiffer with more millage to the point now where it does not need any time to heat up and if stiff, ratchet release. But the second the motor is Killed it clutch feels like new, soft pedal, ETC. No Problems until the motor is bumped or started.

I am LOST!

[Cone Junky]

I would certainly have the flywheel examined closely. Maybe the donkeys that worked on it in the first place mounted it incorrectly and/or damaged it.

I think just the process of elimination points toward the flywheel.

[rioredstang]

Did you replace the pilot bearing when you did the motor? I had a machine do a crank once and for some reason they removed the pilot bearing. I did not notice till installing the clutch disk that it was missing. You could also check crankshaft end play. It still sounds like the throw out bearing is binding on the transmission shaft. I would get it up on a lift and let someone operate the clutch with the engine off, then with it running and watch clutch arm movement. Shine a light in the bell housing and watch the engagement.