HELP: LS3 + T-56 + LS7 clutch - issues
04-23-2016, 01:27 AM
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HELP: LS3 + T-56 + LS7 clutch - issues Hi good folk,
I have an LS3 in a kit car, it is mated to a T-56 (circa 2005) and an LS7 clutch. It is all brand new, well it's now 2,500kms old.
The slave cylinder I have is whatever came with the gearbox, OE unit, are there different types/sizes of slave cylinder? I thought they were all the same on these boxes?
The master cylinder is a Tilton 7/8 and the clutch line is -4.
I have issues shifting gears at high RPM. At low RPM everything is fine, but above about 3500 (and it gets worse as RPM goes up) I have to seriously push HARD to push past the synchro to get in to 3rd and 4th. Even the 1-2 shift is not right at high RPM.
I can stop the car and go from 1st to reverse without issue, no crunching, no issues whatever. If I'm sitting still in neutral I can clutch in and go straight to reverse no problems.
It's like the high RPM centrifugal forces are changing clearances or something, and I can't figure it out.
I have bled the system a lot of times, and I don't believe there is any air in there. The friction point is up near the top of the pedal, nowhere near the floor. The box came from a VZ Commodore down here in Australia, same era as a Pontiac GTO.
I wouldn't even post here with this info, I would just be out there pulling the gearbox out to check everything, but unfortunately due to chassis design the box cannot be dropped - the engine/box have to come out as one unit and that has flies on it!
It's been suggested to me that I should drill a hole in the bellhousing to check the throwout bearing clearance, and possibly also a larger cutout and place a 1mm washer on each bolt under the pressure plate as it may be over-throwing the clutch.
Can anyone offer suggestions please, particularly around slave cylinder variations?
Cheers
I have an LS3 in a kit car, it is mated to a T-56 (circa 2005) and an LS7 clutch. It is all brand new, well it's now 2,500kms old.
The slave cylinder I have is whatever came with the gearbox, OE unit, are there different types/sizes of slave cylinder? I thought they were all the same on these boxes?
The master cylinder is a Tilton 7/8 and the clutch line is -4.
I have issues shifting gears at high RPM. At low RPM everything is fine, but above about 3500 (and it gets worse as RPM goes up) I have to seriously push HARD to push past the synchro to get in to 3rd and 4th. Even the 1-2 shift is not right at high RPM.
I can stop the car and go from 1st to reverse without issue, no crunching, no issues whatever. If I'm sitting still in neutral I can clutch in and go straight to reverse no problems.
It's like the high RPM centrifugal forces are changing clearances or something, and I can't figure it out.
I have bled the system a lot of times, and I don't believe there is any air in there. The friction point is up near the top of the pedal, nowhere near the floor. The box came from a VZ Commodore down here in Australia, same era as a Pontiac GTO.
I wouldn't even post here with this info, I would just be out there pulling the gearbox out to check everything, but unfortunately due to chassis design the box cannot be dropped - the engine/box have to come out as one unit and that has flies on it!
It's been suggested to me that I should drill a hole in the bellhousing to check the throwout bearing clearance, and possibly also a larger cutout and place a 1mm washer on each bolt under the pressure plate as it may be over-throwing the clutch.
Can anyone offer suggestions please, particularly around slave cylinder variations?
Cheers
