91 ZF6 Clutch Hydraulic Issues
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91 ZF6 Clutch Hydraulic Issues
This is an Email I wrote to ZFDoc describing the issue I'm having ATM, any help would be greatly appreciated
I'm having some somewhat major issues regarding my ZF6 on my 91 Corvette that I believe to be hydraulics related. I first noticed a knocking noise from the trans about once per engine revolution with the clutch all the way depressed, but the car shifted fine and I avoided said noise by not pushing the clutch quite to the floor, but where it still fully disengaged the clutch. The next time I drove it I tried operating the clutch in the same fashion, but I would start hearing the knocking before the clutch was even fully disengaged and when I put the clutch to the floor it would labor the engine and reduce the RPM by a few hundred. Additionally, as I was hobbling the car home it became harder to put into first gear and as i accelerated onto the highway it felt like the clutch was slipping and I got a big puff of smoke enter the cabin and a burning clutch smell. I got the car home turned it off and fully depressed the clutch pedal 3 times and each time the range of the clutch decreased until the third time where the clutch would move about an inch before feeling completely locked up at a point. The next day I started the car up and just tapped the clutch and instantly I heard a catastrophic grinding noise that lasted for about 2 seconds before I shut the car off. So I pulled the slave cylinder off and there was fluid on the underside of cylinder but nothing major and no huge leaks when I unbolted the slave. When I inspected the slave cylinder rod it was completely moveable side to side as if it was broken off, and it felt terribly clunky and as if it was binding internally. I was not able to move the rod in at all by hand. When a friend depressed the clutch a few times I held my hand on the rod and it didn't even react. So clearly I need a new slave cylinder and per your website reccomendation I'll be replacing the master cylinder as well. The reason I'm contacting you is because upon removing the slave cylinder there was LOTS of metal shavings on the inside of the bell housing. I stuck a boroscope in there and found a few 2-3 inch spiral shaved shaving and many more tiny shavings but no visible chunks of metal. I was wondering what you believe resulted in the shavings, what exactly is getting shaved off and how bad of an idea it is to replace the hydraulics and continue driving the car until winter without cleaning the shavings or investigating further. Obviously, that would be somewhat of a bad idea, but qualified shops are backed up for weeks and I figure it's worth a try to get me through the year. For further context, the master cylinder fluid was below low and the fluid cap wasn't sealed at all it was bent half open. The car had an LUK clutch kit and clutch fork installed 5000 miles ago which up to this point had zero issues and felt great. The car drove around 10-15 miles since the original knocking noise.
I'm having some somewhat major issues regarding my ZF6 on my 91 Corvette that I believe to be hydraulics related. I first noticed a knocking noise from the trans about once per engine revolution with the clutch all the way depressed, but the car shifted fine and I avoided said noise by not pushing the clutch quite to the floor, but where it still fully disengaged the clutch. The next time I drove it I tried operating the clutch in the same fashion, but I would start hearing the knocking before the clutch was even fully disengaged and when I put the clutch to the floor it would labor the engine and reduce the RPM by a few hundred. Additionally, as I was hobbling the car home it became harder to put into first gear and as i accelerated onto the highway it felt like the clutch was slipping and I got a big puff of smoke enter the cabin and a burning clutch smell. I got the car home turned it off and fully depressed the clutch pedal 3 times and each time the range of the clutch decreased until the third time where the clutch would move about an inch before feeling completely locked up at a point. The next day I started the car up and just tapped the clutch and instantly I heard a catastrophic grinding noise that lasted for about 2 seconds before I shut the car off. So I pulled the slave cylinder off and there was fluid on the underside of cylinder but nothing major and no huge leaks when I unbolted the slave. When I inspected the slave cylinder rod it was completely moveable side to side as if it was broken off, and it felt terribly clunky and as if it was binding internally. I was not able to move the rod in at all by hand. When a friend depressed the clutch a few times I held my hand on the rod and it didn't even react. So clearly I need a new slave cylinder and per your website reccomendation I'll be replacing the master cylinder as well. The reason I'm contacting you is because upon removing the slave cylinder there was LOTS of metal shavings on the inside of the bell housing. I stuck a boroscope in there and found a few 2-3 inch spiral shaved shaving and many more tiny shavings but no visible chunks of metal. I was wondering what you believe resulted in the shavings, what exactly is getting shaved off and how bad of an idea it is to replace the hydraulics and continue driving the car until winter without cleaning the shavings or investigating further. Obviously, that would be somewhat of a bad idea, but qualified shops are backed up for weeks and I figure it's worth a try to get me through the year. For further context, the master cylinder fluid was below low and the fluid cap wasn't sealed at all it was bent half open. The car had an LUK clutch kit and clutch fork installed 5000 miles ago which up to this point had zero issues and felt great. The car drove around 10-15 miles since the original knocking noise.
