QuestionQUESTION: I have a 1980 Spitfire 1500. I replaced the clutch and the slave cylinder. With the engine off, I can shift into every gear. With the engine running, it will not go into any gear, and attepts at reverse cause a grinding noise. I can see the operating lever move when I depress the clutch pedal. What do you think is the problem?
ANSWER: Hi Tom,
From what you say it is obvious that the clutch is not releasing when you depress the clutch pedal. This fact does not pinpoint what is wrong so you need to do a few tests and tell me the history before you put in a new master and slave cylinder. I am guessing it didn't work before the cylinders were replaced or why did you replace them? How long has the car sat unused? When you installed the new cylinders, and bled the system, does the pedal have good resistance as soon as you start to depress the pedal? How much free play is in the pedal?
If the car has sat for a long time (6 mo. or more) it is very possible that the disk is stuck to the flywheel due to rust. If a pilot bearing is locked to the 1st motion shaft. The disk is rusted to the 1st motion shaft due to rust on the spline. Any or several of these can make it not shift into any gear when the engine is running.
Let me know about the pedal feel etc. and I will tell you a method I used with about 50% success rate to brake a clutch loose without removing the engine if it has been setting for a long time.
Howard
---------- FOLLOW-UP ----------
QUESTION: I originally dismantled the trans because it downshifted hard, and I thought the synchros may have been worn-- but they looked alright. After the car sat while I rebuilt the leaking brake MC, the clutch pedal fell to the floor. All the fluid leaked out at the slave cyl and emptied through the bell housing. So I replaced the slave cyl and the 3-pc clutch while at it. I now believe the hard shifting was related to a bad clutch. I had been driving the car almost daily in the couple months prior. I believe I need to better bleed the clutch (since I was able to shift after pumping the pedal a few times, and there is too much play in the pedal before it engages), and I now have a 2X4 holding the pedal down as recommended. In a day or two I'll rebleed the system, and hopefully that will solve it. BTW, I have never worked on cars till I got this, and am pretty much learning as I go along. I appreciate your knowledge and help on this, and will likely need more help in the future.
AnswerYou should not have more than about an inch or so free play in the clutch pedal.
What is the 2x4 on the clutch pedal for? Are you trying to bleed the clutch by yourself?
Clutch systems are sometimes hard to bleed all the air out because the clutch line is large enough to allow a bubble of air to drift upward each time you try to open the bleeder valve on the slave cylinder to force it downward.
We found several different methods that work well. One easy one is to fill the reservoir and just open the bleeder valve with a hose on the bleeder valve pushed down in a can or bottle. (Nothing on the clutch pedal) The fluid will drain into the container and you MUST watch the level closely so as to not let it get below half. Than close the bleeder valve and fill the reservoir and push the pedal down and let it up very slowly and push it down again and let it up very slowly. Repeat that several times and note the feel of the pedal and the free play.
The pedal should feel firm after the first inch of free travel. If you let the pedal up too fast, the spring that keeps the piston retracted will force the piston back fast enough to draw air in around it. This don't happen after the system is bled because then the pressure plate is pushing the piston back.
Even when everything is correct, you have to hold the pedal all the way to the floor to get the clutch released. The TR-6 suffered from the same problem and we found that BLM didn't allow enough travel in the slave cylinder piston to properly release the clutch. This is evident when a new disk is installed because a new disk is not perfectly flat until it gets a little ware on it. Plus the spring movement between the two half lining on the disk is also not been compressed much until it is in and used a little. BLM should have used a larger bore master or a smaller bore slave or used a different leverage on the clutch arm in the bell housing.
This is compounded if the installation of the transmission was difficult because the input shaft (1st motion shaft) can easily warp the disk if the trans is allowed to hang down or move too much when installing. It can actually warp the center hub of the disk so that the disk wobbles when released. Thus it drags and will not completely release.
It is important to keep all of these things on mind when installing a new clutch system in Spitfires or TR-6s.
good luck, let me know the progress.
Howard
