spec stage 3, release point?
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From: waterford MI.
spec stage 3, release point? well, in the middle of swapping dads spec stage 3 that got prematurely worn. Im sure partially due to him learning how to drag race/burnout. but Im worried that the .115" shim is also partially to blame.
had installed a brand new flywheel at the same time. the release point was only about 1-2" pedal travel. it felt great and was easy to shift very fast while driving. but, I think the thick shim might have been compressing the fingers a little bit ALL THE TIME. which would make the pressure plate lose some of its clamping force. so im goin to swap out the stock spec shim .115" for one I made out of .033" sheetmetal. well, actually two of them for a total of .065". should lower the release point to near the middle of the pedal travel.
ok, long story short, just wondering what other people's thoughts are on this? or if you have a similar experience. or if your spec stage 3 and .115" shim has the same release point and havent had any issues and its lasted to alot of abuse? not ruling out the possibility that dad just killed it all together, and nothing mechanically is to blame.
but at this point, cant believe its a problem either.
chris
had installed a brand new flywheel at the same time. the release point was only about 1-2" pedal travel. it felt great and was easy to shift very fast while driving. but, I think the thick shim might have been compressing the fingers a little bit ALL THE TIME. which would make the pressure plate lose some of its clamping force. so im goin to swap out the stock spec shim .115" for one I made out of .033" sheetmetal. well, actually two of them for a total of .065". should lower the release point to near the middle of the pedal travel.
ok, long story short, just wondering what other people's thoughts are on this? or if you have a similar experience. or if your spec stage 3 and .115" shim has the same release point and havent had any issues and its lasted to alot of abuse? not ruling out the possibility that dad just killed it all together, and nothing mechanically is to blame.
but at this point, cant believe its a problem either.
chris
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From: waterford MI.
weird. so when you installed the trans, it slid all the way in until the bellhousing was touching the trans? or did you have to use the bolts to pull it the rest of the way on? I did. i havent installed dads new one, cause we havent made up our mind (his mind. ) which one he should get. I thought Id just be able to replace the clutch disc since it still engaged very smoothly and isnt warped. and it JUST started slipping. but when I pulled it apart, NO F'n WAY. there are deep grooves in the flywheel and press. plate from the aggressive clutch disc.
where is your release point though and how many miles do you have on yours? are your #s dynojet or mustang? dads car makes 417rwhp on a mustang dyno so it could be just a handfull of HP less then yours N/A on a dynojet.
where is your release point though and how many miles do you have on yours? are your #s dynojet or mustang? dads car makes 417rwhp on a mustang dyno so it could be just a handfull of HP less then yours N/A on a dynojet.
Iroc, you need to make sure that you crack the bleeder on the slave if you are having issues getting the trans to bolt up. Using the bolts to pull the two parts together can cause more damage than good. You should not need to do this to get the trans back on. Let me know if you have any further questions. Thanks!
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From: waterford MI.
Originally Posted by SPEC-01
Iroc, you need to make sure that you crack the bleeder on the slave if you are having issues getting the trans to bolt up. Using the bolts to pull the two parts together can cause more damage than good. You should not need to do this to get the trans back on. Let me know if you have any further questions. Thanks!
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From: Port Charlotte, FL
Also, too many people blindly just shim, leave shims out, etc. You need to MEASURE the air gap between the throw out bearing with the slave collapsed and the pressure plate fingers to determine what size, if any, shim is needed. To do this, you leave the bellhousing on the back of the motor, lay a straight edge across it and measure from the face of the bellhousing (bottom of the straight edge) to the fingers. From there, you collapse the slave (push the TOB all the way in- which on the F body will require you to crack the bleeder) and measure from the face of the trans to the face of the throw out bearing. The bigger measurement should be on the bellhousing to flywheel and GM spec is .125-.150 (1/8" or a touch over) for the gap (difference between the two).
If this is too tight, it can cause premature slipping as the clutch wears, reduced pressure plate clamping force and in extreme cases- can even hurt the thrust bearing in the motor.
If it is too loose, it can cause release issues- clutch dragging, not going into gear, high RPM shifting issues, etc. and in extreme cases may be bad enough to push the slave apart as the clutch wears.
This is actually a very critical measurement when doing clutch installs and for proper clutch operation, yet nobody ever discusses it and it is rarely mentioned in clutch manufacturers instructions- when I feel it would cut back on a LOT of clutch complaints/problems if the customers knew to measure that from the beginning. Granted, the clutch should be manufactured to fit and work properly without the customer having to worry about this, but I have seen quite a bit of variance from clutch to clutch.
Joe
If this is too tight, it can cause premature slipping as the clutch wears, reduced pressure plate clamping force and in extreme cases- can even hurt the thrust bearing in the motor.
If it is too loose, it can cause release issues- clutch dragging, not going into gear, high RPM shifting issues, etc. and in extreme cases may be bad enough to push the slave apart as the clutch wears.
This is actually a very critical measurement when doing clutch installs and for proper clutch operation, yet nobody ever discusses it and it is rarely mentioned in clutch manufacturers instructions- when I feel it would cut back on a LOT of clutch complaints/problems if the customers knew to measure that from the beginning. Granted, the clutch should be manufactured to fit and work properly without the customer having to worry about this, but I have seen quite a bit of variance from clutch to clutch.
Joe
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From: waterford MI.
cool. some very good info there man. thanks alot. will do that for SURE and report back. might not happen till next week though. the spec stage 3 came with a TO bearing and the shim, so I put it on assuming it was needed. but from now on, i'll measure all clutch's. where do you typically see the LS7 clutch's at out of the box Joe? what about the spec stage 3?
oh yeah, so I can open the bleeder, and push the tobearing all the down to the fully seated/shortest dimension, then snug the bleeder back up right? it would be nice if there was a window in the bellhousing for us to just look up there at. damn modular transmissions.
and your too tight scenario is exactly why I posted this question. Im thinking mine WAS too tight with the .115" shim supplied with the kit.
chris
oh yeah, so I can open the bleeder, and push the tobearing all the down to the fully seated/shortest dimension, then snug the bleeder back up right? it would be nice if there was a window in the bellhousing for us to just look up there at. damn modular transmissions.
and your too tight scenario is exactly why I posted this question. Im thinking mine WAS too tight with the .115" shim supplied with the kit.
chris
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I honestly have never used or installed an LS7 clutch. Quite a few stock clutches, a few Spec 2, 3, 3+ and Twin Disk, a couple Hayes clutches, etc. They all vary a bit from clutch to clutch from what I have seen. Some not enough to worry about, others are way too much.
Joe
Joe
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We suggest the use of our shim on all F-body cars using our single disc clutch kit. Have there been cars that didn't need it...sure...but this is very rare. Let me know if you need anything else. Thanks!
Edited because of miss-wording. JLA
Edited because of miss-wording. JLA
Last edited by SPEC-01; Sep 27, 2007 at 10:46 AM.
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From: Port Charlotte, FL
Originally Posted by SPEC-01
We suggest the use of our bearing on all F-body cars using our single disc clutch kit. Have there been cars that didn't need it...sure...but this is very rare. Let me know if you need anything else. Thanks!
As for the "rare cars that didn't need it"- I agree, but this is why measuring before installing can save a lot of headaches down the road.Oh- BTW- I got my clutch back- thanks!! It looks like it will do the trick. I'm waiting on a couple trans parts and then I'll let you know how it works out.
Joe
Originally Posted by Irocss85
where is your release point though and how many miles do you have on yours? are your #s dynojet or mustang? dads car makes 417rwhp on a mustang dyno so it could be just a handfull of HP less then yours N/A on a dynojet.
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From: waterford MI.
well, update. I learned that the press plate bolts are torque to yield. learned the hard way. 
anyways, back to the topic, I didnt bother trying the supplied .115" spacer, cause I thought it was way too tight. and I was right. with .065" spacer in there, there was 0 clearance. so I removed one of my shims (.034" sheetmetal cut to fit) and now I got .129" clearance. I'll report back later where the releast point ends up after break in and everything. remember it was only 1" down (pedal barely pushed in) before, and I feel this led to the premature wear on the clutch. we'll see how this one goes. the new one is a spec stage3+. wont get too many street miles, the car is hardly driven. but we'll break it in the right way before hitting the track with it.
chris
anyways, back to the topic, I didnt bother trying the supplied .115" spacer, cause I thought it was way too tight. and I was right. with .065" spacer in there, there was 0 clearance. so I removed one of my shims (.034" sheetmetal cut to fit) and now I got .129" clearance. I'll report back later where the releast point ends up after break in and everything. remember it was only 1" down (pedal barely pushed in) before, and I feel this led to the premature wear on the clutch. we'll see how this one goes. the new one is a spec stage3+. wont get too many street miles, the car is hardly driven. but we'll break it in the right way before hitting the track with it.
chris