Spec 3+ before shim too low with shim too high
03-31-2009, 05:10 PM
#23
Pics of the two different TOB/Slave Assemblies Here are the shots I mentioned yesterday that indicate the difference in the two Slaves. The bearing with the black-backing/spacer is the one that was purchased from a local GM dealer by one of our customers. The one without it is the one that we had on the shelf. They have the same casting number on the part and they were bought using the same OE part number. That being said here are the differences between the parts.
The OE shim is .165" thick; this is .050" thicker than the shim we provide with our kits. The compressed height difference, with the respective shims in place is .075" meaning that the bearing's compressed height is .025" different without the shim.
These number make it clear that several issues could arrise. If you installed the shim we provide on a slave using the black spacer fitted by GM the clutch geometry would be much taller than needed (nearly .190" taller) leading to a clutch that releases high and that potentially slips as a result of the bearing riding the diaphragm fingers.
If you installed it without our shim then you would still have a height that is still .075" taller than intended. I have not been able to find a confirmed date for the addition of the black spacer by GM. It seems that the dealers are unaware of any change. Pair this with the same part numbers (evidencing no change in their parts system) for both slave/bearing assemblies and you see how chaos could insue! I am still digging for more info and will update you all as it is available! Thanks!!!
The OE shim is .165" thick; this is .050" thicker than the shim we provide with our kits. The compressed height difference, with the respective shims in place is .075" meaning that the bearing's compressed height is .025" different without the shim.
These number make it clear that several issues could arrise. If you installed the shim we provide on a slave using the black spacer fitted by GM the clutch geometry would be much taller than needed (nearly .190" taller) leading to a clutch that releases high and that potentially slips as a result of the bearing riding the diaphragm fingers.
If you installed it without our shim then you would still have a height that is still .075" taller than intended. I have not been able to find a confirmed date for the addition of the black spacer by GM. It seems that the dealers are unaware of any change. Pair this with the same part numbers (evidencing no change in their parts system) for both slave/bearing assemblies and you see how chaos could insue! I am still digging for more info and will update you all as it is available! Thanks!!!
03-31-2009, 05:17 PM
#24
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WOW I didnt know my little problem would bring this all out. Im glad that spec is looking into it. My slave didnt have a shim behind it.
04-01-2009, 08:42 AM
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DAMN i just did my clutch last Sat, but it seems to work fine, but its my first clutch other then stock what it came with..... but no problems so i guess im lucky?
04-01-2009, 01:58 PM
#26
If your slave didn't have the black OE spacer then the issue of incorrect height on the part of the slave and bearing assembly wouldn't be the cause. If you pull the kit check the stack height as this will evidence whether the clutch is relative to the issue you are experiencing. Stack heigh is measured from the mounting surface on the back of the crank to the diaphragm finger peak (with the disc in place and the plate bolted to the flywheel). Thanks!
04-01-2009, 02:45 PM
#27
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Now that the clutch is feeling good Im not pulling anything apart for a while haha. Im satisfied with using my homemade shim for now. I will probably need to replace the clutch assembly one day and plan on buying another 3+ setup. I will try to get the new bearing from you so this problem doesnt come back up.
04-02-2009, 03:40 PM
#28
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My TOB did, too. I couldn't get the 1/8" gap with the stock TOB, but I did with the Spec TOB. FWIW, I just got the car started the other day and have not driven it, yet. So, I don't know how mine is going to turn out.
04-04-2009, 09:50 PM
#30
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I don't have a spec clutch but I am also having some problems shimming my clutch. Ive measured it several times tonight and keep coming up with with a gap of .260. Does this seem unusually large to anyone? I have a Monster stage 5 bolted to a eagle crank in a 6.0 block.
04-06-2009, 08:21 AM
#31
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Why don't you guys use the shim? IIRC, it's 1/8" (.125") thick and would bring both of your guys' measurements within tolerance. I've heard the Monster clutches don't need shimmed, though. Has your flywheel been turned down?
