4L80-E drains fluid on the pavement overnight

I'm stumped. I can't find the leak. I replaced the gasket...re-sealed the wiring harness connector. No fluid visible on the pan or around it.
The fluid is draining from the top and dripping onto the rear tranny support
cross member, then drains down the crossmember to a hole and onto the street.
I ran the truck for about an hour and climbed under it...no signs of any leakage. Half hour later, still no signs of leakage. Thought I had it fixed.
Went out this morning and found a puddle under the truck. It is dripping pretty steadily now.
This is a 92 K2500 with 454 (7.4L) extended cab, long bed with 187,000 miles on the truck and 110,000 miles on the tranny. No slippage or any other reason to replace the tranny. I'm about to drive it into the dessert, strip the VIN and leave it for dead...but I wuv my truck.
Do these things have drain back valves? I can't find one.
Any help?
Nate
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do you think it is the seal on the tranny were the shaft goes in to the torque converter??
Bill
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pull the dipstick when it's leaking
it will probably be WAY over full.........the converter is draining back into the pan and it probably coming out the vent tube

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Here is one for you. Do you have the trans dip stick that has the little lever the locks down? They had found that these trans were blowing oil out the dip stick tube so they started to use dip sticks that have a lever that squeezes a rubber bushing sealing the dip stick tube. If yours just has the standard dipstick maybe you are blowing the fluid out the dipstick tube and it is pooling someplace and then slowly draining... I suspect that the tail shaft seal is actually leaking (seal the the drive shaft goes into). I have seen this leak and run back the tail onto the rear mount. The real bad part is that this causes accelerated degradation of the rubber mount. So when you do find you leak check the rear mount.
Good luck,
mark
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Sorry guys. Based on my post, you're all on the right track. The same track I was following. But one minor detail was overlooked on my part...sometimes new parts CAN be bad right out of the box. The new pan seal was leaking. Gawd I feel stupid. Got a new pan gasket from the dealer (Freakin expensive seal I might add) that has the crush collars. Will install this weekend after all the tranny fluid leaks out to below the pan level so it won't be such a messy job...LOL
The seal has started to disintegrate in many spots. It looked fine the other night after a cruise. But it apparently failed in the rear, right above the motor mount (should it be called a tranny mount?) where it is hard to see. I assumed, since it was a new seal, the leak was coming from above. I always look like an mule (PC cleanup tool) when I assume. The oil then dripped off a lip of the seal, preventing it from getting the pan itself wet. Last night there were six spots where I can see the seal has broken...mostly near a bolt hole...and beginning to squeeze outward. 8 dollar gasket from NAPA (comes with a filter)...money thrown into the wind. I could take it back and bitch...but I think I'll just get on with my life. NAPA doesn't have a history of supplying bad parts so I won't blame them.
Thanks for the input and sorry for wasting your time.
Nate
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From your description, it sounds like you overtorqued the pan bolts. It is critical that the pan flange is flat at the holes and that you torque the bolts properly. Dave

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I had a thought...if I torque them to the specs, which are based on having crush collars...will it be too much torque on a rubber gasket without crush collars? Either that or my torque wrench is out of calibration.
Nate

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. Re: 4L80-E drains fluid on the pavement overnight Thu, Sep 18, 2003, 3:08pm (CDT+5) From: snipped-for-privacy@spamcantfindmenvbell.net (Nate)
I had a thought...if I torque them to the specs, which are based on having crush collars...will it be too much torque on a rubber gasket without crush collars?
Either that or my torque wrench is out of calibration. Nate .
Too much torque without the collars
Scribb Abel
In a pinch...............wet boogers make for a good adhesive.......when allowed to dry for a period of time.
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