clutch saga

I'm not sure if a long post is the best way to introduce myself, but here goes anyway. I'm a new owner of a 1999 G20, which came without rust, but with clutch problems. The pedal needed to be pressed completely to the floor in order to shift and sometimes it wasn't possible to get the clutch disengaged. The previous owner was adamant that the clutch was good - "I had a new clutch put in 20,000 miles ago" – and that “something else” must be causing these problems. Whatever. I figured I would bleed the hydraulics, replace the master and slave if necessary, and pull the transmission if all else failed.

The bleeding went well for a couple minutes but eventually there was a kind of a whoosh and the pedal fell to the floor. After that, no amount of pumping made a difference. I figured it was time for a new master and slave. (This post by Robj80's post made up for the failure of the FSM to mention that the clutch pedal box needs to come out in order to remove the master cylinder: http://www.g20.net/forum/showthread.php?83614-clutch-master-install.) I bench bled the new master and installed it, only to watch as the reservoir slowly drained to empty. Where was the fluid going? Dripping on the ground, leaking from the hose the runs from the reservoir to the main body of master cylinder. Repositioning the clamp on the end of the rubber hose didn't stop the leak, and it also didn't help when I used a worm gear clamp in place of the original pinch clamp. (Getting a new clamp tightened down in that small space was a challenge.)

So I removed the new master cylinder and discovered that the copper crush washer under the fitting for the reservoir hose was defective - marred by several large burrs and imperfections that prevented the fitting from being tightened properly. Ridiculous.

After I got the leak from the master stopped, I bench bled it, installed it again, and connected it to the new slave. The bleeding went well at first (again) but then it started to feel like someone had jammed a brick under the clutch pedal. There was no give in the pedal at all. Investigating, I was surprised to see that the slave cylinder pushrod was fully extended and that there was no spring tension pushing back on it. Isn't pressure from the pressure plate supposed to move the pushrod back into the slave when the pedal is released? I could force the pushrod back into the slave by hand, but after pressing on the clutch pedal, the lever the slave pushrod presses against would not move back into the fully retracted position. The way in which the original bleeding operation firmed up the pedal and then with a whoosh fell to the floor made me think that maybe the release bearing had been pushed all the way off the input shaft. In fact, I had noticed when I removed the pedal box that the previous owner had adjusted the clutch pedal pushrod all the way to the most extended position – maybe with air out of the lines this actually pushed the throwout bearing too far forward?

At this point I realized nothing was going to get fixed until I pulled the transmission. (15 minutes of glaring in frustration at the slave cylinder didn't seem to produce any telepathic results.) After removing the transmission I could see that in fact the throwout bearing was no longer on the input shaft - it had fallen off the lever assembly and was jammed sideways into the pressure plate. I could also see why the lever assembly wouldn't move back into the fully retracted position. The bell housing was saturated with clutch dust and the part of the bellhousing in which the clutch lever pivots was completely clogged with grease and soot. The lever could barely move. (Since the friction disc wasn't too badly worn I think that all that dust and soot in the bellhousing must have been left over from the clutch job 20,000 miles ago that the previous owner told me about.)

I ordered an Exedy clutch kit and cleaned out all the grease and dust form the bellhousing. Using new clips, I got the new throwout bearing clipped into the lever and the whole thing moving properly on the input shaft. Progress! Much to my disappointment though I couldn't get the new friction disc to slide freely on the input shaft. (RidiculousX2.) Not wanting to wait for a new disc from Exedy, I got a friction disc from my local Infiniti dealer and that fit fine. (After the job was finished I returned the friction disc to Exedy and they informed me that some kind of defect caused the friction disc hub to be off by nearly a millimeter - enough to render it useless.)

With the new clutch and hydraulics in place and working, the car is great fun to drive!

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I learned a few things doing this clutch job:

- Robj80's post about how to remove the clutch master saved me a lot of grief - http://www.g20.net/forum/showthread.php?83614-clutch-master-install.
- When removing the clutch pedal box on my 1999 P11 I found that I could get a good view of the top bolt on the pedal box if I looked at it through a space just to the right of my fuse box. From that angle I had a straight shot at the bolt with a socket on a very long ratchet extension. Seeing the bolt makes it easier to remove than trying to do it just by feel.
- Using a swivel adapter also helped in the removal of the clutch master and the pedal box, and re-installation was made easier by jamming the nuts for the master into my socket with strips of paper. I also wouldn't try to remove the clutch master without a long magnetic pickup tool.
- He's no EricTheCarGuy, but this video was a helpful demonstration of transmission removal on a Sentra: http://www.youtube.com/watch?v=hHkLtu0OIyI. (There are 4 parts to the video altogether.)
- I didn't remove the front center beam or the front of the exhaust when pulling the transmission. I liked having the center beam in place as a secondary support for the engine, and I didn't feel like battling with rusty exhaust hardware. Leaving the cross member and the exhaust in place caused an inconvenience, because with these things in place access to the top bolt on the rear transmission mount was blocked by the Y brace thing that supports the intake manifold. There is a cut-out in the Y brace that I think is supposed to make it possible to reach that top bolt, but the cut-out just wasn't deep enough. I persuaded it to be a bit deeper with a high-speed grinder.
- I read a bunch of worrisome posts about trouble with the starter bolts. The starter bolts look similar to bellhousing bolts - that is, they look like the bolts that hold the transmission to the engine. Unlike these bolts however, they pass right through the engine. Looking at the transmission from the driver's side fender, the bellhousing bolts at the 1 o'clock and 2 o'clock positions are actually the starter bolts. I didn't have to remove the battery cable or solenoid wire in order to remove the starter bolts - I just left the starter resting in place once it was unbolted.

-Dan