Siezed Clutch

[ksbeta]

Howdy. Picked up a '71 240z a month or two ago to give my '70 a buddy. We don't get around to the local clubs often, so I could tell the green car was getting lonely. Only too happy to oblige.

The car hasn't been run in close to a decade, but otherwise the list of things it needs are far shorter than another will-not-be-named project I attempted earlier this spring. After getting it running (shop vac proved helpful for removing acorns from carbs), I found there was absolutely no resistance in the clutch pedal. Replaced Slave/Master cylinders, vacuum-bled the system and attempted to run once more. No-good. Looks like the clutch is seized.

I'm planning on replacing the motor (stock L24, head allegedly has a mild cam) & transmission (roadster 5-speed) this fall, so the object of getting it running was simply to enjoy the car as-is in the meantime without digging into it too much. That being said, I really don't want to separate the transmission or replace the clutch. So...

I came across this write-up for resolving the issue: http://www.chicagolandmgclub.com/techtips/general/604.html

I was going to give it a shot this Saturday. If the flywheel explodes, so be it. Any other non-invasive ideas? I've heard running a screwdriver in the clutch-fork and wiggling might free the rust as well.

[tlorber]

Interesting technique. You definitely want to be in 5th and not reverse when doing this-unless you don't like your "friend".

When you pull the tranny, you should go to the 311s.org site. Those roadster 5 speeds are tough to find and people pay good $ for them.

[Zed Head]

I would try driving it (start it in first gear) and getting on and off the throttle, with the clutch pedal down, to shock the clutch free. Same effect, just tapping it free instead of pounding it with a huge sledge.

I assume that you've confirmed that the slave cylinder actually moves the fork when the clutch pedal is pressed. New parts have been known to be bad.

[5thhorsemann]

I would just tow the damn thing behind a pickup truck in 5th gear, motor not running (make sure the brakes work) with the clutch depressed on a 20 foot tow rope. Once the disk pops loose pump the clutch a few times to clear the rust. FWIW

[Carl Beck]

The method described should work..

I just put the car on an empty street. Start the engine in 1st and get the car rolling about 15mph - then yank the E-Brake hard, while pressing down on the gas. Usually takes a couple to three or four trys. Of course you have to be ready to turn the key off if you run out of street...

FWIW,

Carl B.

[MotoManMike]

Is the clutch stuck depressed or engaged? If you try to push the car with it in gear will it move?

[ksbeta]

Hey Thanks for the input everyone. Mike - When the car is off, I can shift it between gears successfully, such that when I turn it on I'm in that gear. When the motor is running, any attempt to shift results in grinding, regardless of whether I'm pushing on the clutch pedal or not.

[olzed]

So have you bled the system again. Put a clear plastic hose into a jar with some brake fluid in it.Put the other end on the slave bleeder. Get an assistant to push the pedal down while you crack the bleeder. See any bubbles? You might still have air in there.

After a proper bleed and everything is good, there should be some resistance to the pedal.

[MotoManMike]

Gotcha. Ok so the clutch is staying ENGAGED. OLZED is on the right track for sure. Have a friend look at the clutch fork while you are in the car and not the results when you press the pedal down. I've had issues with using aftermarket slave cylinders where I actually had to adjust the rod that attaches to the pedal itself from the clutch master cylinder (thing filled with oil on the firewall) and have fun, that cotter pin has been the waste of many of mens afternoon I had to bleed the system, they rotate the threaded rod out toward the pedal itself so when you push the pedal the rod travels a further stroke into the clutch master cylinder. The old original Z cars had an adjustable rod on the clutch slave where most of the aftermarket ones do not. If the slide of the throw out bearing is stuck and will not slide on the transmission shaft, you may have to tap on the clutch fork with a BFH to get it to break free and slide again. GOOD LUCK!!!!

[ksbeta]

Tried it. Neither way worked.

Afterwards we put it in first and I started it while my buddy pushed it. Was able to successfully drive around the block a couple times that way, although I never could shift out of first. New clutch & transmission, here I come. Anyone have an '81-'83 ZX Non-Turbo 5-Speed lying around in the DC area? Or Dallas?

[Carl Beck]

OK - First - when your friend let the jack down - I did not hear you REV the engine While applying the HAND BRAKE. Secondly - as stated you may have to try that a couple of times.. Not stop at 1.

When the clutch disc brakes lose - you will feel pressure in the Clutch Pedal.

An Edit from the above:

I just put the car on an empty street. Start the engine in 1st and get the car rolling about 15mph - then yank the E-Brake hard, while pressing down on the gas AND HOLDING THE CLUTCH PEDAL TO THE FLOOR. Usually takes a couple to three or four trys. Of course you have to be ready to turn the key off if you run out of street...

Also - you have to make sure your rear brakes are properly adjusted - otherwise the E-Brake won't get enough grip to stop the wheels.

BTW - were you holding the Clutch Pedal to the Floor - when your friend dropped the Jack?

You don't need a new clutch and tranny - you just have to learn the process of breaking a frozen clutch disc free.

try everything again... Clutch Pedal To the Floor - REV the engine and Stop the REAR wheels with the E-Brake.

good luck,

Carl B.

[Zed Head]

Still haven't seen any evidence that you know that the clutch fork is moving and pressing on the springs on the pressure plate. You can actually see the fork and slave cylinder from the engine bay, you don't even need to jack the car up.

You might be spinning your wheels (pun intended!) until you know that for sure.