Clutch problems.......advice?
Clutch problems.......advice? Bought this car as a roller with engine and trans out. Rebuilt the LT1, installed new clutch (parts store OEM replacement), new hydraulics from WS6Store.com, flywheel milled, everything torqued to spec. The trans shifts fine with the motor off, but when it's started, it goes into forward gears hard, will not go into reverse. Also it engages almost right off the floor. Has anyone else had this problem with an OEM replacement clutch? I see where it is a common problem with the aftermarket performace stuff, but I didn't think it was an issue with what I have. I just wanted some opinions before I convert the master cylinder to an adjustable.
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Joined: Oct 2008
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From: Rochester, NY
I've got a theory or two as to why it wasn't working right, but nothing that I could really prove, and the only real fix for me was to make my MC adjustable.
In your case, I'm willing to bet that the uncompressed thickness of your friction disk is just a hair to thick for your hydraulics to disengage completely, so its dragging a bit and causing the clutch to engage completely right off the floor board.
Wish I had more correct advice for ya, and hopefully someone who does might chime in. It does, however, sound like you know your stuff and you've done your homework on LT1 clutches, so assuming you've looked the whole system over and are confident you've got everything bolted together right, I'd say your best bet is to do the adjustable MC.
LT1 flywheel shims don't exist, you have to make your own if you decide to do this. There are a handful of guys out there that do, but I have never ever heard of someone having problems with clutch engagement, and a flywheel shim solving the problem on an LT1. LS1 flywheel shims exist, because they're necessary for those cars.
I had the same problem as you a couple years back except with a Spec clutch. After I bled my hydraulics 100 different times in different ways, bought a new OEM clutchfork, bought a new OEM flywheel, retorqued my pressure plate bolts, and tried just about everything imaginable my clutch still wouldn't disengage right.
I've got a theory or two as to why it wasn't working right, but nothing that I could really prove, and the only real fix for me was to make my MC adjustable.
In your case, I'm willing to bet that the uncompressed thickness of your friction disk is just a hair to thick for your hydraulics to disengage completely, so its dragging a bit and causing the clutch to engage completely right off the floor board.
Wish I had more correct advice for ya, and hopefully someone who does might chime in. It does, however, sound like you know your stuff and you've done your homework on LT1 clutches, so assuming you've looked the whole system over and are confident you've got everything bolted together right, I'd say your best bet is to do the adjustable MC.
LT1 flywheel shims don't exist, you have to make your own if you decide to do this. There are a handful of guys out there that do, but I have never ever heard of someone having problems with clutch engagement, and a flywheel shim solving the problem on an LT1. LS1 flywheel shims exist, because they're necessary for those cars.
I've got a theory or two as to why it wasn't working right, but nothing that I could really prove, and the only real fix for me was to make my MC adjustable.
In your case, I'm willing to bet that the uncompressed thickness of your friction disk is just a hair to thick for your hydraulics to disengage completely, so its dragging a bit and causing the clutch to engage completely right off the floor board.
Wish I had more correct advice for ya, and hopefully someone who does might chime in. It does, however, sound like you know your stuff and you've done your homework on LT1 clutches, so assuming you've looked the whole system over and are confident you've got everything bolted together right, I'd say your best bet is to do the adjustable MC.
LT1 flywheel shims don't exist, you have to make your own if you decide to do this. There are a handful of guys out there that do, but I have never ever heard of someone having problems with clutch engagement, and a flywheel shim solving the problem on an LT1. LS1 flywheel shims exist, because they're necessary for those cars.
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I'm going to try the adjustable master cylinder mod and see if that fixes my problem. Obviously the clutch is dragging, I haven't even driven the car yet, just fired it up in the garage, so I shouldn't have any syncro problems unless I leave it the way it is. I know the clutch fork is on correctly, the pivot point was also in correctly. The only thing there could be wear on either of those parts, but they looked good to me. I'll post when I get the mod done. I am going to try to get to it this weekend.
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Verdad Gallardo Yes the plastic cup is on the end of the slave. I would have to check the Helms manual for the torque spec, but whatever it says is what I used. It was 2-3 months ago and I can't remember the spec.
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Joined: Apr 2008
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not doubting your work. sometimes clutch installs do bring out "wtf" issues.
I do know if TQ is to much on PP bolts you will have disengagement issues.
other causes which have been covered
bad hydraulics or in need of bleeding
bent clutch fork
clutch fork not on correctly
lose clutch fork pivot ball stud
bad/deformed/bent TO bearing
clutch itself is bad (bent hub/spline or warped disc)
unfortunately pulling the tranny to inspect from there is likely in your future if the adjustable does not resolve your issues.
FWIW stock hydraulics have always worked for me and the only cause for disengagement issues was when I got careless with the air gun on install of PP bolts which wound up being WAY to tight as a result
good luck
I do know if TQ is to much on PP bolts you will have disengagement issues.
other causes which have been covered
bad hydraulics or in need of bleeding
bent clutch fork
clutch fork not on correctly
lose clutch fork pivot ball stud
bad/deformed/bent TO bearing
clutch itself is bad (bent hub/spline or warped disc)
unfortunately pulling the tranny to inspect from there is likely in your future if the adjustable does not resolve your issues.
FWIW stock hydraulics have always worked for me and the only cause for disengagement issues was when I got careless with the air gun on install of PP bolts which wound up being WAY to tight as a result
good luck
Thanks for the info. When I get home I will check the Helms manual torque specs to make sure they are correct. I did inspect the clutch fork and the pivot stud and didn't see anything that made me think there would be a problem. I did also torque the pivot stud to the spec in the Helm manual. The hydraulics are new pre-bled assembly from WS6store.com. Clutch, PP, and TO bearing are all new, not that that means I couldn't have a bad one. Thanks for the help.
TECH Regular
Joined: Oct 2008
Posts: 492
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From: Rochester, NY
As for torque, 22 is the official number for stock disks, however if you go a little over 22, it won't hurt anything.
Example: Spec calls for 30 ft lbs on their LT1 clutches (Valeo pressure plates).
When it comes to pressure plate bolt torque, you just need to be careful not to tighten them so much that it distorts or cracks the aluminum pressure plate. This would cause disengagement problems.
Ok, the torque spec in my Helms manual was 22 ft lbs and that is what I used, so I am good there. I did the adjustable master mod and it seems to have fixed my problem. I haven't got it on the road yet, as it's raining here now and I have to drive through the yard to get it out of my shop. It does go into each gear smoothly now just sitting in the shop. Hopefully my problem is solved. Thanks for the advise.
i made my stock master adjustable... cut about 3/4" out of the rod, used a dye to thread it, used a 2" threaded rod to join the two, adjust as needed. I spent about $10 making it, as opposed to spending $180 on McCleods adjustble master, which is exactly what they do to theirs..
