I have an ‘02 Trans Am and just got a new clutch kit from Spec, and a new slave from Tick. When measuring for a shim, Spec states that measurement B should be .175 to .225 less than measurement A, but Tick says that B should be .0625 to .125 less than A. Does anyone know which of these measurements I should be following? I want to make sure I don’t screw this up and wear out my clutch.

 

As long as the slave is not so close it's always pressing on the fingers...which should be near on impossible, it really doesnt matter a damn where it sits.

All this shim stuff is nonsense.

There is literally no position the slave could end up ( other than above ) where it would wear out a clutch. And if it was this close, it would slip very early.

 

Stevie, I have to disagree. These things are extremely sensitive to the slave being positioned too far from the clutch fingers. Lots of issues not being able to fully disengage the clutch which absolutely sucks. It needs to be in the correct range, I’ve dealt with it countless times

 

This.....

 

So, how far should the release bearing be from the pressure plate?

Thanks.

 

So I emailed Spec and Tick a got responses from both of them that matched up in the end.

The Spec Rep replied with the below..

• "With the bearing pushed all the way back, the optimum gap between the bearing and fingers is .200” This is where the bearing works best and allows for the fingers to rise as the clutch wears."

The Tick Rep replied with this..

• "The correct specification is .100-.300". We prefer to be with the .150-.200" range for optimal usage. So the SPEC numbers are correct. With or without the shim you will still be in spec. I would however recommend going with our .055" shim to make the measurement optimal at .201"."

The Tick website has just been updated, and the old distances of .0625 and .125 have been replaced. So the most optimal distance to be at is .200"

 

It's a simple linear motion slave.

It will not care whether it starts fully compressed, or 5, 10 or even 15mm out. As long as there isnt so much travel as to push it beyond the seal. But if the clutch is that far away, then that is one hell of a mismatch of parts used, if it is even possible.
And this is the whole point/benefit of such a hydraulic setup...it's fully self adjusting so the release will always be in close proximity...ie touching the fingers.

 

I'm not saying that you are wrong, but how else do you explain a clutch not fully disengaging?

 

Without seeing the car and install, it would be impossible to say.

But whether the slave starts at rest, say 5mm out, 10mm out, 15mm out....the slave doesnt know any different. It still requires the same amount of fluid movement to move it from that rest position, to fully extended, which is ultimately all that matters.

There seems to be a massive obsession with changing masters and all sorts over there in the US on these cars. Which seems bizarre really. Because certainly on any Euro, Jap or other car....the master is a fit for life deal from the factory. Very very rarely do they ever need changed, yet on LS cars people want to change them all the time ? Makes no sense that GM could have got something so wrong on one group of vehicles, over so many years of production.

Slaves do suffer more wear and tear but these usually do get changed at clutch changes. But unless the clutch itself was a totally wrong fitment for the vehicle...the fact the hydraulic slave/system is basically self adjusting, should mean no shimming or any other nonsense is ever needed.

 

So your argument is that since foreign cars don’t require any adjustment, that there’s no way LS cars do?

Riddle me this then. If it “just works”, then why have people gone to such lengths and effort to make these measurements, shim their slaves when they didn’t have to do anything at all and it just worked fine in the first place? Why do clutches come with *specific* instructions, in bold, to make sure you have the correct air gap?

I guarantee you, if you put a slave in with 15mm of air gap between the TO bearing and clutch fingers, you’re gonna have a car you can’t put in to gear, and you’re going to be taking the transmission right back out to get it moved in to spec. The only reason you’re saying it “just works” regardless of air gap, is because you’ve never done it, otherwise you’d know better.

I don’t know how else to say it other than you’re just wrong on this one.

 

Except if there was a 15mm gap from new install....by nature the hydraulic system/spring will move the bearing in contact with the fingers so there is now zero gap.

There is no adjustment needed in a properly designed hydraulic system. That's why they use them.

And if you ever did get a clutch with a 15mm gap....I'd have to ask is that clutch actually designed for that application in the first place ?

Why there are so many clutch problems over there vs the rest of the world...is a really good question

 

I don't know what else to say, other than you have to do your due diligence and measure on these cars. If you don't, and you're out of spec, and you put it together anyways, you're gonna have a bad time, that's just all there is to it and that's proven.

 

Hello, just a quick question, there should be about 0.200" clearance between the throwbearing, before it bottoms out on the hub, Correct? So, when the clutch wears, and pressure plate fingers moves outward, the bearing has enough movement, so the clutch fully engages.

Thanks.

 

Yup..