jeff73

Anybody know what the travel is on a t-56 throwout slave? I have a ls7 clutch behind a 09 truck motor and was checking bearing to see if it needed shimmed and found out that when it is installed in the car that it has about .300 of an inch preload when fully depressed. That is I would have to machine the flywheel that much just so it would not engage the clutch when the slave is fully depressed. Any body else ever have this prob?

stevieturbo

are you saying the release bearing is hard against the fingers and actually pressing against them to release the clutch, without the pedal being depressed ?

Or something else ?

Something I always meant to measure was slave travel, never did get around to it though

jeff73

Yes. That is exactly what I am saying. I have double checked my measurement a couple of times and get the same. Everything is factory gm parts. I have never heard of having to shim the bellhousing out to get the right spacing, but that's what the measurements are telling me.

Darth_V8r

iTrader: (4)

I do t know if this will help but here goes:

When I did my clutch measurements, I cracked the bleeder and fully compressed the slave and got that measurement back to the trans/bell mating surface.

Other was clutch fingers to trans/bell mating surface.

Fully compressed slave measurement was .105 less than clutch finger measurement. If I didn't compress the slave, I got negative numbers like you're describing.

So, 2.5-3mm Slave free play based on that measurement. Slave max travel is 13mm. Fully disengaged on my clutch was 11mm best I could tell from measuring at wonky angles.

So figure 8mm travel needed to disengage tge clutch plus the free play.

All that to say - did you absolutely fully compress the slave when you measured?

jeff73

Sure did. Cracked the bleeder, did everything I could think of to find more travel in the slave. I have about .750 of travel which the guys at d and d performance said is right. I got the clutch from Mike at Eastcoast performance 3 years ago and found out He passed away, so I Can't ask him,(good guy). I ran the clutch a couple of months last year after I went through the trans. Had a slight hang up going into 3rd which is why I took it out and decided to check the clutch spacing. Could not find anything wrong inside the trans.

kingtal0n

iTrader: (1)

In alot of cars, the slave uses a pin, or certain length rod to press into the clutch fork. You might try changing the length of this pin/rod.

if you have a TOB hydraulic, then I think you can change the size of the TOB to adjust distance. In both cases I would think, differing TOB thickness by .3" sounds like alot though. Almost sounds like the clutch master isn't full resetting back to zero.

you are on the right track, do not let the TOB ride the pressure plate or it won't last nearly as long, do whatever it takes to fix.

stevieturbo

So slave/bearing/bearing holder are all correct and used for their intended application ? Given it's an LS clutch fitted to a truck, there has to be potential for a mis-match somewhere

Have I seen someone else mention the rear flange on some cranks might be different ? ( not in terms of bolt holes, but actual flange depth ? )

Exactly which trans and bellhousing, I think some bellhousings were a different depth ? ie those on later cars that had a proper bearing for a spigot bearing vs older cars that used the needle roller deeper in the crank ?

Potentially their slave could be taller ?

stevieturbo

Buy a cheap USB camera so you can poke it in there and see exactly what's happening too if it is still together.

nmass399

Post up the measurements of everything you have so we can take a look at it. I have a stock bellhousing and an aftermarket I can measure with a motor plate sheild and stock tob/slave. Measure that crank flange to, I don't think it's different but I can check an ls1 flange while I'm at it

nmass399

Also what bellhousing are u using?

Darth_V8r

iTrader: (4)

I don't think the truck crank is offset differently than any other LS crank. But it almost sounds like it somehow is sticking out too far. Is there possibly a defect on the flywheel preventing it from going all the way on?

jeff73

Ok, first I have had a dumbass moment. I am using a vernier scale that measures inside and outside on the same scale and I was recording measurements on the outside when I should have been using the inside and the difference is .300 of and inch. That being said I have .300 of an inch from the block to the crank flange surface and 3.088 of total clutch and flywheel height which gives me a total height of 3.388". The distance from the bellhousing surface to the TOB fully retracted is 3.336" which still gives me .052" of preload on the clutch fingers, which means I need to come up with .232" to get room for clutch wear. the bellhouse is 5.560" tall and the TOB is 3.460". The TOB and bellhouse are from a 2002 Camaro.

nmass399

ok measurements i got is crank flange to block mating surface = .3125, Tob fully extended total length from very bottom edge to tip of the bearing = 3.5625, Tob fully extended mounted on f-body t56 = 2.9375. tob distance fully pressed was around .750. Was using tape measure so its gonna be off by a hair.

nmass399

You needed to measure the tob mounted on trans instead of the full measurement of the tob from what i can see.

jeff73

well I think I found the rest. Completely disassembled the TOB and found quite a bit of the grease they use on the shaft in the bottom. Cleaned it out and used caliper on the o-ring put it back together and it would go clear to the bottom. That should give me the space I need. I hope that was it. Thanks for all your help!

Darth_V8r

iTrader: (4)

that makes sense. Something was acting as a slave shim and closing that gap up.