Tail Shaft on ZF6 leaking
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Burning Brakes
Joined: Mar 2003
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From: Bowling Green KY
Tail Shaft on ZF6 leaking
The tail shaft of my ZF6 on my 92 Vette is leaking. Anyone ever had that happen? :confused: If so, any ideas if it is hard to fix? Any info would be appreciate
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Joined: Apr 2000
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From: Texas
Re: Tail Shaft on ZF6 leaking (Brian Blum)
Past the driveshaft yoke or where the tailshaft mates with the body of the transmission?
If it's past the yoke, just pull driveshaft, pop the seal out and replace. Be sure to jack the rear of the car up higher than the front so the tranny lube doesn't run out when you do this. While it's out, examine the yoke for signs of excessive wear. Sometimes the seal will wear a groove in the metal. If that's the case, the yoke will need to be replaced.
If the leak is where the tailshaft mounts to the transmission "body", there's a gasket in there that may be the culprit. Unfortunately that's not usually the case. The ZF uses steel bolts threaded into an aluminum body to hold the tailshaft in place. Combine that attachment approach with the constant flex of the c-beam and what usually happens is the bolts pull the threads out. I had this happen on my '96. 4 of the bolts stripped out the aluminum threads :( To repair, I pulled the tranny and used a Time-sert kit. There used to be a Tech-tip on this written by Hib Halverson who had the same issue on one of his ZFs Depending on which bolts are stripped (if that's the problem), you may be able to leave the tranny in the car. Unfortunately all mine were at the top which left virtually no room to drill the holes larger for the installation of the Time-sert.
If it's past the yoke, just pull driveshaft, pop the seal out and replace. Be sure to jack the rear of the car up higher than the front so the tranny lube doesn't run out when you do this. While it's out, examine the yoke for signs of excessive wear. Sometimes the seal will wear a groove in the metal. If that's the case, the yoke will need to be replaced.
If the leak is where the tailshaft mounts to the transmission "body", there's a gasket in there that may be the culprit. Unfortunately that's not usually the case. The ZF uses steel bolts threaded into an aluminum body to hold the tailshaft in place. Combine that attachment approach with the constant flex of the c-beam and what usually happens is the bolts pull the threads out. I had this happen on my '96. 4 of the bolts stripped out the aluminum threads :( To repair, I pulled the tranny and used a Time-sert kit. There used to be a Tech-tip on this written by Hib Halverson who had the same issue on one of his ZFs Depending on which bolts are stripped (if that's the problem), you may be able to leave the tranny in the car. Unfortunately all mine were at the top which left virtually no room to drill the holes larger for the installation of the Time-sert.
