LS7 engagement is "delayed"
11-26-2012, 05:41 PM
#1
LS7 engagement is "delayed" So i've had my LS7 clutch in for a couple years now and i love the thing. It grabs right in the middle of the pedal travel, is smooth, and it still grabs real hard. I have not taken my car to a drag strip and I don't plan to, the only times I have driven the car aggressively has been a few local HPDEs which the clutch takes minimal abuse since I am not powershifting or anything like that (smooth = fast). Today I took the car out for the first time in a while and decided to give it a good romp in first and slam second. Well when I did this the clutch seemed to be "delayed" before it grabbed second. I don't think it was slipping as it doesnt smell and still grabs plenty hard. I also did the ol' 'throw it in 6th at a low rpm and apply full load' to test if it is slipping, and nope, it held fine. I'm thinking it might be time for Tick Master Cylinder..... Thoughts?
11-27-2012, 11:06 AM
#3
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I believe yours may be suffering from forced slow reaction.
Mine does the same, but there is also a 1/2 inch of master cylinder push rod clearance befor eit hits the piston, and, drum roll, an orifice needing drilled out.
The slave cylinder has to be removed for the orifice drilling as the orifice is in the the end connecting tio the m/cyl. Remove m/cyl, punch out roll pin retaining the hose in m/cyl, remove hose, and drill out, use 1/8 inch drill bit, the orifice in the hose end.
Clean out chips, lube O-ring, install hose end into m/cyl, install roll pin from removal, and install m/cyl onto firewall. Bleed system.
If there is alot of pedal rod slack, you can hack saw the rod, thread each end of the cut, add a union and two locknuts, and adjust out the slack once installed.
Mine does the same, but there is also a 1/2 inch of master cylinder push rod clearance befor eit hits the piston, and, drum roll, an orifice needing drilled out.
The slave cylinder has to be removed for the orifice drilling as the orifice is in the the end connecting tio the m/cyl. Remove m/cyl, punch out roll pin retaining the hose in m/cyl, remove hose, and drill out, use 1/8 inch drill bit, the orifice in the hose end.
Clean out chips, lube O-ring, install hose end into m/cyl, install roll pin from removal, and install m/cyl onto firewall. Bleed system.
If there is alot of pedal rod slack, you can hack saw the rod, thread each end of the cut, add a union and two locknuts, and adjust out the slack once installed.
12-05-2012, 09:45 AM
#7
This could be relative to fluid transfer between the slave and master as the pedal is released (like what you would see with old masters prior to the drill-mod or like what you would expect if you were seeing bleed-by within the master cylinder). Another possibility is that the SAC-mechanism in the LS7 plate is faulty and this is causing the plate to hang-up a bit.
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12-06-2012, 12:03 PM
#9
The SAC-mechanism can do some odd things. Originally intnended to maintain consistent engagement through the life of the clutch, if it miss-adjusts it can affect release and engagement. If the clutch was slipping the RPM's would jump but the car would have no increase in speed or forward momentum. This should be fairly obvious when it happens.
12-07-2012, 10:01 AM
#11
You can try restting the SAC-mechanism but it can miss-adjust again. The best option is to replace the clutch assembly with an option that eliminates the SAC-plate like our SC09 clutch/SC75 flywheel. If you decide to go this route let me know and I will be happy to assist you. Thanks!