Slave cylinder

[Detroit Bill]

I have been monkeying around with with my slave cylinder and I have discovered a few things. I did this with guidance but I think some could learn from it so I thought I would share.

Be aware if your slave is not set up and adjusted properly it will cause shifting problems (duh, right) But the clutch may feel correct.
Here was the slave setup in my car as it came.



Behind the piston of the slave cylinder was this spring.


With the spring in it is difficult if not impossible to adjust the clutch. There will always be pressure on the fork.

I removed the spring at which point the piston went too far back in the cylinder and the oil began to leak past the seal.




The seal is "blown up" by oil passing through the holes in the back of the piston. The rim was past the bleeder hole fluid would leak past when the piston went all the way back.



I put a button of weld on the back of the piston to lengthen it by enough to stop the leak and ground it to a measured length.

I then bled the slave and compressed it so I knew it was bottomed and then adjusted it with around 1/16" of play. When the slave cylinder settled it took up the slack.

I also changed the spacers and made a new slave clutch rod from a grade 8 bolt.

Here is a photo installed without the boot so I could easily see what was going on and adjust it.



There was a few effects from this adjustment.
1.) The car goes into gear, shifts and downshifts more easily.
2.) The clutch engages further from the floor telling me I gained fork travel
3.) A ticking I would get from the throw out bearing went away.

So if your Tremec does not shift as smooth as you would like you might want to check your slave setup.

I am going to make a new bracket to center the slave cylinder rod in the bore. But other that that I am very happy with it.

[rodneym]

Did you leave the spring out?

[Detroit Bill]

Yes, I left it out.

[patrickt]

Why isn't that the default set up from the factory?

[Detroit Bill]

The "factory" does not include a slave cylinder.

[twobjshelbys]

Yes, you need to get better alignment on the rod. Lengthening it helps but I can tell you from experience that the misalignment will result in premature wear of the gasket and it will leak.

[rodneym]

Bill,
You have pics of a black and unpainted slave. Did you go through one already?
I know this part. It's a GM/Isuzu part that Superformance installers seem to be fond of. It used to be made in USA, believe it or not. Now, China. They have good travel and they're cheap (~$15) but I eventually went with a CNC slave.
Good that you removed the spring. Mike Forte doesn't like pressure against the clutch, and when I made sure there was no contact (via return spring), the semi-frequent squeals went away. Some say the Mustang style contact is the way to go, but taking Mike's advice is what did the trick for me.
Using this setup "as is" has been a part of some mysterious issues for some.

[Detroit Bill]

Good catch. I bought a new one. It it a Duratec(?). I was hoping it did not have a spring. It did. For $15 I decided to keep it. It was made in China. I have not measured the actual travel yet. I am considering going with the CNC unit I am concerned it does not travel as far. I'll measure and decide before I make a new bracket.

[TimG427]

It looks like you have Teflon tape on the line, is that ok? I just installed a new slave cylinder and it's leaking from the line.

[patrickt]

Originally Posted by TimG427

It looks like you have Teflon tape on the line, is that ok? I just installed a new slave cylinder and it's leaking from the line.

Before you tape it, take it apart, wipe it off good, and blow it out with compressed air. Try not to get fluid on your paint....

[Detroit Bill]

Originally Posted by TimG427

It looks like you have Teflon tape on the line, is that ok? I just installed a new slave cylinder and it's leaking from the line.

That happens to be paste (I think). I have added a longer hose since that photo so I could rotate the hose further.

[patrickt]

Originally Posted by Detroit Bill

That happens to be paste (I think). I have added a longer hose since that photo so I could rotate the hose further.

You know what's funny is that Tilton goes out of their way to say "DO NOT use PTFE tape or thread sealer..." in their instructions, but if you install the wonderful Speed Bleeders they are quite happy to sell you a bottle of thread sealer to go with them and to use a hair dryer when you install them (I guess that's if your hair is wet). see: Speed Bleeder Installation

[trularin]

Originally Posted by twobjshelbys

Yes, you need to get better alignment on the rod. Lengthening it helps but I can tell you from experience that the misalignment will result in premature wear of the gasket and it will leak.

I'll second this comment. Happened to me as the clutch pedal bled down while shifting on I75 mid-day. Since then, aligned rod better and used hardened steel ( no flex ).

[Detroit Bill]

I have better alignment than is depicted in that photo. I may create a new bracket if needed to correct it 100%. I picked up a used Dake bandsaw for work that should make it easier.

vertical bandsaws: Work-A-Matic SXC - Dake Machine Tools,*SXC

I have a massive critical project going on at work that will make the Cobra take a back seat for a while.

For projects:

I want to get the side pipes re-coated (and O2 bungs welded in).
Rear main seal fixed.
Hesitation/stumble after 6,000 RPM shifts fixed, I may let a tuner go after this.
Then I'll go after the alignment of the slave rod.

[King- cobra]

Great info