Having transmission problem(s), '92 Chevy pickup

[Rumble]

Update:

I put in a couple 8-oz bottles of ATP AT-205 like some of you suggested. Have driven the truck a total of 80+ miles since, and it's driving/shifting without any issues. The erratic engine bucking-misfire is gone, runs smooth with good shifts. Will have to give it a few days/weeks to see if the strange intermittent leakage problem clears up, but I haven't noticed anything yet. I was skeptical whether this stuff would work, but so far I'm impressed!

 

[Rumble]

A few days after my previous post above, the erratic bucking-misfire returned. Here's the good news, I removed and cleaned all my spark plugs and found my #8 plug was severely corroded at the boot terminal connector. In fact, the boot terminal was nearly rusted away and barely making contact with the plug. So it looks like the misfire was due to this bad wire & corroded plug all along, and not the transmission. So maybe my trans is fine, although I can't explain the mysterious, intermittent fluid leakage over the past year. I've not seen any leakage in over a month though, so maybe that issue has cleared up. Apparently, these two issues were unrelated. Going to put in some new wires and plugs tomorrow (did cap & rotor tonight).

 

[kc8adu]

i remember some older transmissions would drain the contents of the converter overnight intermittently and leak out the vent or if the seal was bad the dipstick tube.
would make a huge mess.
was rare and mostly cars that were garage queens.

 

[CorvairGeek]

Originally Posted By: kc8adu
i remember some older transmissions would drain the contents of the converter overnight intermittently and leak out the vent or if the seal was bad the dipstick tube.
would make a huge mess.
was rare and mostly cars that were garage queens.


x2

The 2-4 accumulator cover o-ring will do exactly this on the 700R4/4L60/4L60E. It's on the passenger's side of the vehicle towards the bell housing. Right by the dipstick, which can do the same thing.

 

[Rumble]

Thanks for all the advice everyone. I'm going to replace the dipstick tube seal as soon as I can get one.

Drove the truck today after finishing the plugs/wires cap/rotor and it runs like new. I should have caught this bad spark plug wire sooner than I did. Now that I'm sure the trans is ok, I may invest in a diagnostic tool to keep up with any future problems before they happen. Never really planned to have this vehicle for 25 years, but new truck prices have gotten crazy over the years.

 

[andyd]

Just for grins, crawl underneath and check out the brake lines. Glad you fixed up the truck.

 

[zzyzzx]

I had a friend that had a mystery transmission fluid leak. Had the pan gasket replaced at least twice and didn't make a difference. I took one look at it and saw that it has this smaller pan vertically mounted on the side, which was leaking. Fixed that and that solved the problem. The guy was very happy about that; it was leaving a trail before. Moral of the story is the really look around for leaks all over. There really are all kinds of places on the casing where there are test ports, and then there are those spats for the accumulators. All of those can leak.