Freeing a Stuck Clutch

©By: John T. Blair (WA4OHZ)
dot_clear 1133 Chatmoss Dr., Va. Beach, Va. 23464; (757) 495-8229

Originally Written: September 2009

The following is a discussion of a common problem, a stuck clutch! This is especially true for cars that aren't driven all the time.

A fellow on one of the list I subscribe to wrote:

It appears that I have a clutch problem with my '78 Spitfire (this car has overdrive). A couple of weeks ago, while attempting to move the car it would not go into gear. Thinking it was a clutch master cylinder/ slave cylinder problem, I have replaced both items and bled the system. The car will still not go into gear.

Any idea of the cause?

clutch parts Let's step through the trouble shooting: 1. You need to be sure that the clutch release arm is trying to release the pressure plate. When you press the pedal does it have some resistance when you depress the clutch pedal?

If not it's probably a hydraulics problem. Check the clutch master cylinder for fluid, and bleed the slave cylinder.

Note: If the vehicle has a cable operated clutch, then it's possible that the cable has broken.

2. You need to confirm that the clutch was actually refusing to release?

Have a helper presses the clutch pedal, while you look at the release arm. Can you feel or see the actuating rod moving?

If there is no motion of the release arm,

a. For hydraulics systems, (assuming that the clutch master cylinder reservoir is full and the system is bleed) the problem could be the linkage from the slave cylinder to the release arm is out of adjustment, or the release arm is broken. Lets assume it not a broken release arm. But if the rest of the troubleshooting is OK, then it is probably a broken release arm , a disintegrated release bearing, or a broke pressure plate out, and the transmission will have to be removed and the various part of the clutch assembly examined.

Check that the activating (adjusting) rod is intact and moving. It may just be out of adjustment. Typically the release arm should be able to move about 1/16" when the clutch pedal is released. If it can move more that 1/16" it needs adjustment. I've seen them very loose, bent, or missing.

b. For clutches that are cable operated, then there is either too much slack in the cable or the cable is broken. Try to adjust the cable.

3. If all the above is fine, chances are that the clutch disk is stuck to the flywheel and the pressure plate. To try and break the bond that has formed, you will want to move the car into the open, ie. the street or your driveway. But you say how, I can't get it out of gear. You may have to pull the spark plugs to relieve the compression, put the transmission into a high gear, and get some friends to help you push!

Once in a safe, open area, reinstall the spark plugs. There are a couple of ways to try and break the bond that has formed:

a. Set the handbrake, block the wheels, and put the transmission in 3rd or 4th gear. Then depress the clutch while attempting to start the engine. With any luck this will work. b. Put the transmission in 1st gear, and start the engine. The car will lurch forward and if it starts you will start moving. Now depress the clutch and the brake pedals. Hopefully this will break the clutch free. You may have to repeat this several times.
Good luck.
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