I was driving home yesterday and noticed very slightly that the gear switching was a little rougher than normal. Today I brought my car back to work because the mechanic down the street was going to re-check the alignment he had done for me a few weeks back. Anyways, when I was backing out of my house the reverse shift grinded...usually i can get passed that grinding sound by going to 3rd or 4th and then reverse. In this case it didnt work.

The drive to work was rougher than usual, shifting to 1st or reverse (when needed) ... I am now at work with the car, and 1st gear is very STIFF to shift to; reverse will not go without the grinding noise. I am limiting the shifting, i will just try to get the home as quick as possible (or should i have it towed?) so i can check it out.

I am thinking the problem is the clutch plate...I checked the transmission fluid, and its full. I think when I engage the clutch, its not pulling the gear away from the flywheel (?) far enough...I think either way I cut it, the tranny will have to come out...

Any suggestions???!!!

Did you check the clutch master cylinder level?

Yes, it's full. (This is the reservoir on the drivers side behind by the brake master cylinder right?

Do you guys think bleeding/refilling the fluid would do anything for my problem...or might this be a REAL problem with the clutch itself?

Edited September 12, 200816 yr by mikewags

Sounds like a leaky slave cylinder to me. Check out the condition of the slave cylinder. (pass side of bell housing) Can you adjust this linkage? 280Z... probably not.

Edited September 12, 200816 yr by ZSaint

Try bleeding it. Sometimes air can get into the system even though nothing is leaking out. If you have to drive it you can put the car in 1st or reverse and then start the car. If you have to make a lot of stops you can do this each time. Shifting at as low an rpm as possible will reduce the chance for damage. You can actually shift without the clutch but if you don't already know how to do it now is not the time to learn.

Steve

Just how do you know it sounds like a "leaky slave cylinder"? It could be a few things:

1) As Steve stated, it could simply be air in the line. Bleeding the line will help if this is the case.

2) Leaking master cylinder. Check the firewall inside the car for signs of leakage. Cheap to replace. If the slave cylinder has failed, replace the master cylinder as well.

3) Leaking slave cylinder. Check the slave cylinder for signs of leakage. Cheap to replace. If the master cylinder has failed, replace the slave cylinder as well.

4) Cracked clutch fork.

5) Broken pivot ball.

6) Failed pressure plate.

7) Improper slave cylinder adjustment (yes, it is a non-adjustable slave, but it could be that the spring is not functioning or is absent). Try to wiggle the clutch fork forward and backward. It should only barely move. The throwout bearing rests lightly against the pressure plate fingers. If you can move the fork towards the engine, you may have found the culprit.

It sounds like you have had this problem for a while and it is finally fully manifesting itself. There are a few things you can do to diagnose the problem. It is getting harder to shift into first and reverse because your pressure plate disk is not fully disengaging from the clutch disk. This is caused by insufficient slave cylinder piston travel (see above for possible culprits).

I was experiencing the very same phenomena as you and after pulling my hair out for months I finally tracked the problem down. My ACT pressure plate failed. The rivets holding the rings that contain the diaphragm spring inplace had stretched. This allowed the diaphragm spring to move when acted upon by the throwout bearing.

Thanks for all the advice guys. These tips will definitely help in diagnosing this problem.

I drove the car home. I live about 10 miles from work, so I basically just would turn the car off at the red lights, shift to first, start it up and go. I found it easiest to go straight to 3rd after take off because 2nd was kinda rough. I was able to get home without any grinding or forcing of the shifter (which is good i think).

I am going to bleed the clutch fluid when I get off work tonight, via the slave cylinder. Hopefully there is just air or gunk in the line.

If not, i have the means to replace the clutch/plate assembly --- it's just a pain in the arse doing transmission work.

If you guys have any additional troubleshooting steps for the possible causes of this, feel free to let me know. Thanks again!

It sounds similar to the symtoms I had when my clutch plate was on the way out.

***UPDATE***

I bled the clutch slave after work today. There was some air in the line. I can now shift gears again without the resistance, and once the air was released; the clutch stiffened a bit *was loose before* ...

One last issue though. REVERSE gear grinds. It would do this before, although when I'd start the car and go 3rd or 4th THEN reverse, it wouldnt grind. Now, even when I go to any other gear prior to going reverse, it will make a wicked grinding noise. What does this mean? Last legs of the clutch, or a deeper transmission issue? Any way to fix this that I haven't thought of?

Thanks!

I'm still leaning towards a rapidly failing slave cylinder. That air got in there past a seal somewhere. Bleeding won't totally fix it if the cylinder itself is going bad.

Any suggestion on a good place to buy the slave? And if I replace the slave, I should replace the master as well, right?

I read on another post that you can adjust the slave cylinder...would this do me any good?

I don't think that '75 had an adjustable slave. I'm pretty sure that was just a 240z thing.