Rear main puking, clutch slipping, brand new clutch - ZR-1 Net Registry Forums

FailureCoach · 02-09-2021

Ok I tried to search, but came up empty. I bought a 1991 with 31k miles, records, but.... Apparently a Corvette shop in Florida put a new clutch, flywheel, and balanced it, at least according to their sublet line on the invoice. The older gentleman declined the rear main repair, I believe he was declining in health,and maybe didn?t catch that?s why the clutch was slipping in the first place. So now I have to fix this. Can I buy just a new clutch disc, or do I need a new kit? Not trying to be cheap, just don?t want to throw money away if I don?t have to. Second, best source for the rear main? Jerry?s Gaskets has the whole plate, but states old stock, and seal should be changed. Thanks for any input. My 8th C4, first ZR1, it shares garage space with my ?02 Z06. I?m not new to Corvettes, but I don?t want to screw this one up.

Ccmano · 02-09-2021

The rear main seal is fairly straight forward to replace as it mounts to a removable cover. JerrysGaskets has a brand new seal and cover assembly on his site. You'll need the cover gasket as well. The disc is the only thing that should need replaced if it wasn't driven too long that way. Everything else should clean up just fine. Ultimately you won't know til you get in there.
H

FailureCoach · 02-09-2021

Quote:

Originally Posted by Ccmano

The rear main seal is fairly straight forward to replace as it mounts to a removable cover. JerrysGaskets has a brand new seal and cover assembly on his site. You'll need the cover gasket as well. The disc is the only thing that should need replaced if it wasn't driven too long that way. Everything else should clean up just fine. Ultimately you won't know til you get in there.
H

Thank you. I?ll have to look for the new seal on Jerry?s Gaskets, I only saw the old stock one in the housing. I?m going to call Eisman tomorrow to see if they know what clutch kit they used. The car hasn?t had more than 100 miles since they did the work, if I recall. I just want to have what I need, once I tear it down. Thank you for the input.

Corvette95 · 02-10-2021

Correct me if I am wrong, but if the shop used hydraulic fluid/grease to remove the pilot bearing that will damage the rear main seal as would driving the pilot bearing in too far? This would account for the problems? (just noticed after I replied that the former owner declined the rear main repair, but my reply still stands as help in the clutch replacement)

Ccmano · 02-10-2021

Grease or hydraulic fluid to remove the pilot bearing wouldn't damage the rear main seal but it could push in the oil galley plug in the end of the crankshaft which could cause an oil leak in that area. It would become immediately visible once the flywheel was removed, assuming one is looking for it. While possible, I'd say that's one of the more remote possibilities.
H

FailureCoach · 02-10-2021

Quote:

Originally Posted by Ccmano

Grease or hydraulic fluid to remove the pilot bearing wouldn't damage the rear main seal but it could push in the oil galley plug in the end of the crankshaft which could cause an oil leak in that area. It would become immediately visible once the flywheel was removed, assuming one is looking for it. While possible, I'd say that's one of the more remote possibilities.
H

That doesn?t sound like fun. I?ll have to go back, and look over the shop invoices. I suppose I won?t know much until I get in there. I just hope it goes smoothly. At the end of the day it?s all just nuts, bolts, and money, right?

rkreigh · 02-17-2021

if someone uses the old mechanic trick to pack the pilot bearing with grease and try and pound it out it will push out a crank oil galley plug

you would notice the loss of oil pressure. Look over the clutch disk and if it's hot and glazed don't use it.

I have good pressure plate disk if you need it.

I upgraded to a new stage II I'm dying to try out.

02-09-2021	#1
FailureCoach Join Date: Feb 2021 Location: Canal Winchester, OH Posts: 6	Rear main puking, clutch slipping, brand new clutch Ok I tried to search, but came up empty. I bought a 1991 with 31k miles, records, but.... Apparently a Corvette shop in Florida put a new clutch, flywheel, and balanced it, at least according to their sublet line on the invoice. The older gentleman declined the rear main repair, I believe he was declining in health,and maybe didn?t catch that?s why the clutch was slipping in the first place. So now I have to fix this. Can I buy just a new clutch disc, or do I need a new kit? Not trying to be cheap, just don?t want to throw money away if I don?t have to. Second, best source for the rear main? Jerry?s Gaskets has the whole plate, but states old stock, and seal should be changed. Thanks for any input. My 8th C4, first ZR1, it shares garage space with my ?02 Z06. I?m not new to Corvettes, but I don?t want to screw this one up.

02-09-2021	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Rear main puking, clutch slipping, brand new clutch The rear main seal is fairly straight forward to replace as it mounts to a removable cover. JerrysGaskets has a brand new seal and cover assembly on his site. You'll need the cover gasket as well. The disc is the only thing that should need replaced if it wasn't driven too long that way. Everything else should clean up just fine. Ultimately you won't know til you get in there. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-10-2021	#4
Corvette95 Join Date: Jan 2006 Location: Decatur, AL Posts: 1,119	Re: Rear main puking, clutch slipping, brand new clutch Correct me if I am wrong, but if the shop used hydraulic fluid/grease to remove the pilot bearing that will damage the rear main seal as would driving the pilot bearing in too far? This would account for the problems? (just noticed after I replied that the former owner declined the rear main repair, but my reply still stands as help in the clutch replacement) __________________ Corvette95 Registry and Forum (************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454 Last edited by Corvette95; 02-10-2021 at 07:19 AM.*

02-10-2021	#5
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Rear main puking, clutch slipping, brand new clutch Grease or hydraulic fluid to remove the pilot bearing wouldn't damage the rear main seal but it could push in the oil galley plug in the end of the crankshaft which could cause an oil leak in that area. It would become immediately visible once the flywheel was removed, assuming one is looking for it. While possible, I'd say that's one of the more remote possibilities. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-17-2021	#7
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,087	Re: Rear main puking, clutch slipping, brand new clutch if someone uses the old mechanic trick to pack the pilot bearing with grease and try and pound it out it will push out a crank oil galley plug you would notice the loss of oil pressure. Look over the clutch disk and if it's hot and glazed don't use it. I have good pressure plate disk if you need it. I upgraded to a new stage II I'm dying to try out. __________________ 95 390 LPE ZR1 (505 rwhp) LSV = Lingenfelter Super Vette Twin Turbo 2003 Z06 (800 RWHP)