Solution to Clutch Problems

[vandy0419]

I got my solution!!!

The guy I am going to end up having install the clutch is going to order me a Corvette Master Cylinder :-) This hopefully will solve the problem, its more of a matter of whether or not the lines match up the same.

[WopOnTour]

There seems to be TWO distinct issues as I see it, and NOT just with aftermarket clutches, although they MAY amplify some of the issues.

1. Poor release- making it difficult to shift at times. Some people comment that they must pump the clutch pedal TWICE to make a shift.Often mistaken as a transmission problem.

2. Poor apply/hold - especially at launch or immediately following a shift-resulting in excessive apply slippage and cumulative damage/wear

Poor Release
I'm wondering if the bottoming out rod isnt deflecting the master cyl mounting. It just inserts into something like 20ga sheet metal and locks into place by giving it a 1/4 turn. If that sheet metal is being bent out when the rod stop makes contact, it would push/move the cylinder piston AWAY from the pedal.(somethings gotta give) Once the pedal is released, the master cylinder is going to stay there and now the piston is going to start moving LATE in the pedal stroke. Perhaps an adjustable rod?? or maybe that sheet metal just needs to be bent back, reinforced somehow and THEN a stop added somehow to prevent over-travelling.

Poor Apply/Hold
I'm almost certain that quick connect fitting contains a "damper" valve designed to slow the return/release of fluid from the actuator, slowing the apply of the clutch as a method of tq managment. If you're power shifting, you'll almost always get slippage. If you delay slightly before you put the power on- no slippage.
Now that valve is SUPPOSED to provide unrestricted flow in the apply direction, but I wonder if it's still a restriction. I'm going to take a look at the Saab's clutch hydraulics to see if they are identical or significantly different - they LOOK different in WIS (Saab's Workshop Information System) If there was some way to eliminate that entire "quick coupling" system (and the valve?) and go to a steel braid line- I'm pretty certain clutch performance and shifting ease could be improved.

Wop

[djt81185]

any way u recommend for inspecting the rod? I know once my clutch went weird and its engagement point and feel changed after that permanently...ppl have even commented how my stock clutch felt different...and I have always had trouble engaging first at a stop unless i double clutched it now that I think about it..I've had to double clutch it in almost since the day I bought the car...I'm trying to remember exactly what happened but I forget.

[Tibbett]

Originally Posted by WopOnTour

If there was some way to eliminate that entire "quick coupling" system (and the valve?) and go to a steel braid line- I'm pretty certain clutch performance and shifting ease could be improved.

Wop

I'm getting ready to go out and start working on my car some (more weight related stuff) and I was going to take a look at the setup because I told George I would last night. It seems to me that maybe an SS line and removal of the valve might be in order and I'll see what it'll take to do. If I can get the stuff soon I might go ahead and do this just to see what the results are..

[mgm1979]

here's a question...the problems that are being experienced are with Stage 4 clutches, right?

If we went with Stage 3, think the problems would be the same?

Hope I'm not sounding like a dumbass here...

[vandy0419]

Originally Posted by WopOnTour

Perhaps an adjustable rod??
Wop

Wouldn't this be the point of the Vette Master Cylinder? The one off of the vettes is adjustable, yet if you try going the cheap way and get one off of the camaro, trans am, etc, it won't work because it isn't adjustable for those cars.

[Blu_Redline]

Originally Posted by WopOnTour

2. Poor apply/hold - especially at launch or immediately following a shift-resulting in excessive apply slippage and cumulative damage/wear

Poor Apply/Hold
I'm almost certain that quick connect fitting contains a "damper" valve designed to slow the return/release of fluid from the actuator, slowing the apply of the clutch as a method of tq managment. If you're power shifting, you'll almost always get slippage. If you delay slightly before you put the power on- no slippage.
Wop

I think this hits the nail on the head. I have experienced 2nd gear clutch slippage several times... but only on a WOT pass and doing a power shift. The confusing part was always having the car shift normally on a subsequent run with no slippage. And that was because I never power shifted right afterwards, trying to be careful of a bad clutch, and the clutch felt OK.

[AlphaJaguar5]

Additional Left out Info: (sorry lol )

"The LUK production clutch has to be pre-set in a press to engage the self adjusting fingers,. If that process is not followed after service the clutch can drag and not disengage properly. Virtually all of the repairs I mentioned do not cause the clutch to slip other than a displaced matter cylinder with a binding shaft…"

[socalsilverRL]

exactly...let the clutch engage...then WOT

[sheek360]

good job alpha!