HELP! Desperate! Clutch Problem
Thread Starter
Racer
Joined: Apr 2002
Posts: 353
Likes: 0
From: Tuscaloosa AL
Update on the clutch problem
Well guys, here's the latest on my clutch problem. I bought a new slave cylinder tonight at O'Reilley's (it's a Girling piece) and re-bled AGAIN - I used almost 2 full pints of fluid! I tried about 4 different push-rod lengths and strangely enough, I got my best results from the shortest one?!?!?!??!?! This happens to be the stock replacement piece. While it will now engage reverse without grinding if I hold the clutch in for 7 seconds, and it will allow me to shift between gears with the motor running, it is still grabbing very low, and the shifting is pretty hard. I am going to try SHORTENING the rod a little bit more (I really don't get it why shorter is working better), and if it is drivable, I am hoping the break-in period will work out the hard shifting. What do y'all think? 
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Originally Posted by Mark L. Warner
I was thinking that since a longer push-rod pushes the slave cylinder in deeper in the released state, then it would generate more range of travel when you depress the clutch pedal. Is this not right?
A longer pushrod will just move the TO bearing a little closer to the pressure plate springs, so that less clutch movement is wasted in making up that slack.
The problem is, you don't have enough slave piston movement, and that is a result of a bad bleed, or a leak, or possibly a problem with the clutch pedal linkage or master pushrod not pushing the master piston far enough in to begin with.
Try gravity bleeding the system. This is tough to do because the reservior isnt' very tall and the fluid can drop quickly and introduce air into the lines. To combat this, I cut the bottom off a 500ml water bottle (dried it out well) and wrapped electrical tape around its neck until it wedged into the clutch reservior tightly. Then I filled this up, giving me about 5" of fluid height to work with so I gravity bleed it longer in one shot (by cracking open the bleed valve) without having to jump up there and keep topping off the reservior.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
As far as it "breaking in" the hard shifts are because the clutch is barely disengaging, so the intermediate shaft isn't slowing down right away, which makes it hard for the synchros to grab a gear.
I drove mine like this with a dying master cylinder for 2 weeks, where the fluid level would drop a little and pull some air in, and I kept topping it off, but I basically had a spongy clutch for that time... and hard shifts.
That wore out my synchros bigtime, and the magnetic drain plug was completely packed with metal shavings. It couldn't hold any more.
After the master replacement, and a good flush, I have full clutch travel again, but the synchros are shot I think, and it shifts hard. After pushing in the clutch, I can't shift into first right away, I have to wait for the intermediate shaft to pretty much stop before the wornout synchros will grab it. This really sucks at stoplights.
I drove mine like this with a dying master cylinder for 2 weeks, where the fluid level would drop a little and pull some air in, and I kept topping it off, but I basically had a spongy clutch for that time... and hard shifts.
That wore out my synchros bigtime, and the magnetic drain plug was completely packed with metal shavings. It couldn't hold any more.
After the master replacement, and a good flush, I have full clutch travel again, but the synchros are shot I think, and it shifts hard. After pushing in the clutch, I can't shift into first right away, I have to wait for the intermediate shaft to pretty much stop before the wornout synchros will grab it. This really sucks at stoplights.
Thread Starter
Racer
Joined: Apr 2002
Posts: 353
Likes: 0
From: Tuscaloosa AL
Guys thanks very much for all the input. The more I read your replies, and the more I think about working on it last night, I think the only reason the shorter push rod seemed to work better, was because it was right after I rebled it. I guess I just need to bleed it some more. I think the root cause is slave cylinder plunger travel, and as such, the push rod length shouldn't matter. I was even thinking about more dramatic problems like somehow having the wrong clutch fork or the pivot was wrong or a wrong throw-out bearing. But in all of those cases, while they can cause shifting problems on their own, they have nothing to do with how much travel I am getting at the slave cylinder. So..... next up I will replace the flexible line and bleed, bleed, bleed.
