My 1991 GMC sierra 1500 2wd 350ci developed an atf leak behind the flywheel cover 2 years ago. When driving, it would suddenly dump fluid out creating an oil slick on the undercarrige and up the tailgate. I just had the 700r4 tran rebuilt with the master rebuild kit/seals and a new torque converter. I was told that the pump looked good, ie no scoring on the input bushing.
After re-installing the transmission, it ran fine with no visible leaking for 55 miles, over the course of 3 days and 3 start-stop cycles. On the 3rd day, I noticed that part of the pan was wet, and there were drips from the flywheel cover pinhole.
I checked the level of the fluid to find that it read 3/4" above the full mark.(I was very careful when re-filling however having only put a total of 11 1/2 quarts total into the trans) Despite having my doubts that the trans was overfull, I lowered the pan and drained about 1 quart. After letting it cool overnight, I drove it up the street about 2 miles when it started smoking(dumping fluid over the hot exhaust) I looked under the truck to find a half/dollar size puddle forming at a rate of a drip per second.
The leak seems to be behaving exactly the same as it did before the rebuild.
I dropped the flywheel cover and located the drip to be coming from the seal at the torque converter input to the pump. Could a new seal be leaking? Could the pump be bad even though it passed a visual check?
My truck has 145000 miles, but the trans was new 100000 miles ago.
The fluid I'm using is pensiol ATF "for vehicles formerly serviceable by mercon/dextron atf"
I also put a bottle of Lucas trans in with my atf.
What should I look for now?
I'm sure its not leaking from the pan, and nothing was found in the pan. The fluid is dripping from the tab surrounding the torque converter seal.
have the same problem?
Tuesday, October 23rd, 2007 AT 6:06 PM