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Pulling the T56 from the GTO this week and looking to get a rebuild here locally in Houston. Anyone know of a good reputable shop that will do a good job and not try and sell me all the other parts that are not needed? Seems to be in good shape except the syncro's. Hard to shift.
Looking forward to being back out at COTA with everyone if I can get this gear box taken care of.
Not sure of a Houston "shop" which is why we started doing our own. Joe Dederich is in Dallas.
If we knew each other better we might give it a go - but I wouldn't want any hard feelings.
Is the clutch fully disengaging? What do you mean hard to shift?
We would tell you make sure you have a steel 3/4 fork and fresh billet keys if it already doesn't. You'll want to make sure somebody takes a good look at the sliders when they look at the blocker rings. We have had good success shimming them a couple thousands snug; maybe only 2 if you keep the old bearings.
I’m partners with the AJ Foyt Racing gearbox tech in Motorsport Driveline Tech. We be glad to take this on and are in the Houston area. Call my cell 832-8six3-2314Quote:
Originally Posted by BlueGoat
The more I think about how it was acting, I think Fbody is right. Might be the clutch not engaging fast enough. We had to replace the clutch at TWS and never could seem to get it adjusted as good as it was before. At COTA last year I remember now that I had to let the RPM get down a bit before it would allow me to change gears slowing me down quite a bit. Trying t research now and see what Centerforce clutch and pressure plate was in it before. No real markings on either one of the old ones to purchase the same one.
Do you still have a stock master cylinder? Tick makes an aftermarket piece with a Tilton cylinder. Lots of LS based Camaros and Corvettes had shifting issues, mine included. Only fix was that Tick master.
At the risk of saying something incorrect or stupid ...Quote:
Originally Posted by BlueGoat
Here goes anyway.
My 94 Vette had what was effectively a restrictor in the stock hydraulic line.
I think it was there to limit how quickly the clutch could engage to
protect the drivetrain. They were prone to clogging after 15-20 years of
service if they weren't flushed occasionally. Usually the slave cylinder
would leak as some point and the new ones always came with the lines
attached, somewhat of a self solving problem that people didn't always
realize they had. The issue is that with a lot of shifting, a ridiculous amount
of clutch dust gets drawn into the slave and mixed with fluid. And, on the
Vette at least, it was a major pain to bleed the stupid thing to get clean
fluid all the way through the slave.
I wonder if the stock Camaro clutch hydraulids is the same.
If you double clutch and find that it shifts easier, that points to synchros. If it's the same or worse then maybe clutch/hydraulic issue.Quote:
Originally Posted by BlueGoat
I could be completely wrong.
- Josh
The Tick/Tilton MC is a brute force solution to fixing clutch disengagement issues the right way...Quote:
Originally Posted by Supercharged111
They are; LS/t56 stock clutch lines do have an orifice restrictor to prevent driveline shock issues.Quote:
Originally Posted by 39PitCrew
Commonly when people do clutch jobs on ls/t56 cars and run into post-job disengagement issues, it's always one or more of the following:
1. Insufficient bleeding of clutch
2. Not measuring disengagement free play/distance before reinstall-ing trans.
3. Factory orifice restrictor in stock line makes 1 and 2 worse
Anyways, BlueGoat, your issue could be as simple as #1 or as worse as pulling the trans to get to #2. Do you have any dead play in the clutch pedal? If so you need to re-do #1
For #1, to bleed these things right you need to use a MityVac from the top in addition to bleeding from the bottom first. The way I do it now is I buy two pints of good brake fluid.
Burn the first pint by bleeding the clutch the traditional way by having a helper depress the pedal and you open the bleeder from the bottle.
After you've done that your clutch is full of fresh fluid but likely still has air in it, especially if there is still some dead play in the pedal.
Run to the parts store and get a MityVac, use the cone adapter on the vacuum hose and shove it into the little hole at the base of the MC reservoir and put some vacuum on it. You'll see some air bubble start to stream up. After the bubbles slow down, yank the hose and refill the reservoir, keep doing this until you don't get any more bubbles. Finally apply vacuum one more time. Then reach in the car and pull up on the clutch pedal as hard as you can and you'll get some more air bubbles to vacuum out all over again because the stock MC is great at hiding air bubbles.
Took me a while to figure that out.
If you're confident that your clutch really is bled and there's no dead play in your pedal, you will want to pull your trans and measure your engagement distance/play and shim the slave cylinder. If you're running a bone-ass stock clutch and a stock flywheel that hasn't been cut, you probably don't need a shim. Most other scenarios do demand a shim, and most people don't realize this until the trans is back in the car, so they just pony up for the tick/tilton MC as a brute-force bandaid.
I myself ran into this during my LS swap; had a brand new stock flywheel and PP, but an aftermarket friction disc that was thinner than stock, so I needed a shim between the slave cylinder and the trans.
http://www.tickperformance.com/tick-...im-kit-3-pack/
https://www.youtube.com/watch?v=IsJ805umImg
For #3, the cheap/easy solution is to pull the line off from the MC in-car and perform the drill mod if you don't want to pull the trans to replace the whole hose:Quote:
How to determine if a shim is needed for your setup:
During each and every clutch install you perform on a newer GM vehicle, you must measure to see if a shim is necessary for proper installation. This is done by taking two simple measurements (see worksheet):
1) Measurement "A" is the distance between the surface of the bellhousing that meets the transmission to the tip of the pressure plate fingers. To get an accurate measurement, the clutch must be torqued properly.
2) Measurement "B" is the distance between the throwout bearing surface to the transmission surface that meets the bellhousing. To get an accurate measurement, the slave spring must be removed and the bearing must be fully seated at the bottom of it's travel; resting on the slave's base.
Once you've got your two measurements, make sure that measurement "B" is ~3/16" to 1/8" LESS than measurement "A". If you come up with more than 1/8", add an appropriately sized shim between the slave cylinder and the transmission in order to get the measurements where they need to be.
Your “A minus B” measurement should be 0.125 to 0.200 for adequate bearing travel and to allow for clutch wear. If there is no difference between the two measurements, or if "B" is greater than "A", there could be a problem with clutch engagement which could result in premature clutch slip and eventually a total failure. Contact your clutch manufacturer before proceeding with the install.
https://www.youtube.com/watch?v=sT9_YR9IiC0
https://ls1tech.com/forums/manual-tr...od-review.html
Anyways, if you do end up pulling the trans, invest in a remote slave bleeder hose that is long enough to reach the MC reservoir (forgot the length)...
https://www.speedwaymotors.com/T56-R...der,41385.html
...and ditch the factory line and make your own using 3AN hose/fittings and these adapters:
https://www.summitracing.com/parts/rus-640281
...but you lose the factory quick disconnect, which you can make your own or just do the drill mod on a new stock line and just use that to make it easier to deal with in the future.
You can also follow my whole saga on this here:
http://www.aicmctexas.com/showthread...ghlight=clutch
I also had another issue where the LT1 clutch pedal was shorter than the LS clutch pedal, so I got a RAM adjustable MC which is nothing more than a stock MC with the rod modified with a threaded rod end.
My C5 Z06 developed the issue on its own. I replaced slave and master with new GM parts and remote bleeder, no change. Replaced clutch and shimmed slave within spec, now it's much worse because the pressure plate is stiffer. Install Tick master, can bang gears again and shifts are smooth. There are many cases where ditching stock master is the only fix. Corvette is plagued by having 3 orifices whereas F body only has 1 that is easily drilled out. The Tick can be had in a factory 7/8" bore if you ask them nice, otherwise you get the 3/4" bore. I was worried about it over centering the clutch, but it doesn't feel that way in the car.
Forgot to mention Corvette had a self adjusting pressure plate which is why the master was not adjustable. Pretty sure the F body was the same way as well as anything that came after it. If a non self adjusting pp is installed, some form of adjustable master will be required.
You gotta keep a mityvac strapped to the dash then