Clutch Issues, either slipping or won't disengage, maybe M/C?

[CG240Z]

Hopefully someone will be able to help me out on this. I have a 78' Z with an 83 5spd trans. I'm having problems getting the clutch adjusted properly. It's either slipping or won't disengage. I can't seem to find that happy median. Something that might be causing it is, even with the clutch M/C rod adjusted all the way out, the pedal still isn't returning to the pedal stop. I looked in the service manual and confirmed that the pedal height should be greater than what it is.

I installed a new Autozone M/C and clutch in the car and have read that the rods can be too short. So I pulled it back off and compared it to the M/C that was on the car, same length rod. Also, when I do have the clutch adjusted to where it somewhat engages/disengages, it only actually works the clutch at the last 2 inches of pedal movement. I bought the car non-running, but I'm assuming the clutch pedal should have an even feel the whole way. Not "nothing, nothing,nothing, engage".

Any advice would be great. This is one of the last hurtles keeping my build from getting on the road.

Thanks guys!

[EuroDat]

According to the manual, the pedal height should be 220mm from the floor. My pedal is about 205mm and the free travel is about 15mm. Im running a Close ratio ZX 5sp with a 2+2 (240mm) flywheel and clutch, so its a bit of a mix of several models. Im not exactly according to the manual, but it changes just fine with a smooth pedal all the way to the floor. That depends a lot on the pressure plate you are using.

The clutch pedal should always return to the stop position. If its not, the MC rod is holding it back or the anchor bush is seizing up. I take it the pedal moves freely. Is the M/C rod mounted in the top hole?

The M/C rod should be fitted in the top hole which is forward of the centre line of the pedal arm. The second "lower" hole is back towards the driver and used for the return spring. If these are switched, you can adjust the M/C rod out fully and still not reach the pedal stop. It does make a big difference and could be the cause of your troubles.

Other simple tests you can do are:

1. Measure the clutch fork to the front of the bell housing: Should be around 110mm.

2. If someone depresses the clutch pedal. The york should travel to approximatly 125mm.

Its about 15mm +/-2mm of travel at the end of the clutch fork. Given everything is adjusted right. The 110 and 125 could be a little different with your clutch.

3. You should be able to push the fork about 5 - 10mm into the slave from the rest position. This will give it enough travel to compensate for clutch disc wear.

4. Air is the system can cause a lot of probelms, but from your description. I think, if it has some air in the system, its not the primary cause of your problem.

Chas

Edited March 17, 2014 by EuroDat

[CG240Z]

Thanks for the help! Lots of useful information. Can't wait to get working on the car again and seeing if I can get this problem ironed out.