Leaked Some Trany Fluid while driving, now Trans Slips

While I was driving my WS6 across town a leak developed in the line to my tranny cooler and I lost about 1 quart of fluid. I noticed something was wrong when the tranny started to rev higher than normal before engaging the next gear.
As soon as I noticed this I started looking for the problem, fixed the leak, and refilled the trans fluid to a proper level. But the car is still having the same difficulty.

Can anyone more familiar with automatic transmissions tell me what I am likely looking at for damage? A full rebuild would be a catastrophy for my budget at the moment, so my fingers are crossed hoping this is something specific that won't require disassembling the entire unit to fix.

I know there are additives that could be poured into the trans to keep it from slipping. How long did you drive with the missing quart? Hopefully you didn't damage a clutch or a band.

From the time I first noticed the tranny acting up, to the time I reached the nearest available fluid, was probably about 7-10 miles. During which time I tried to take it easy on the car by lifting off the throttle when it was about to shift, to keep the over reving to a minimum. But now that the tranny is refilled, there is absolutely no change in behavior....perhaps by the time I noticed anything was wrong, the damage was already done.


Anyway, I was reading up on the 4l60e and I came across one article that claims that driving even a single mile, while as little as 1/2 quart low on fluid, WILL absolutely cause damage to this transmission because of "pressure spikes" that can break internal parts or blow out seals. But having never torn into a transmission before, I really don't have any idea what seals that article could have been talking about.

What was your procedure to refill it?

Are you checking it while the car is running etc.? Still might be a little bit low, needs to be exactly full, not too much, not too little.

I'd check the level again.

The level is definetly good now, I just rechecked a 3rd time, and its still right on the money...while hot, while running, after taking a short drive thought all the gears, reverse included, while on level ground. I even insisted on the Dex III that the manual calls for, even though the parts guy was telling me that its outdated and I should just use the more commonly available "new formula" (whatever he meant by that ... is there a Dex IV, now or something??)

Yea, that kind of fluid shouldn't matter.

So it's still hesitating to shift just like before? How bad is it?

It feels like an extra second or slightly over and probably better than an extra 1000rpm when making the 1-2 shift while driving very gently. The 1-2 usually seems to be worse than the 2-3. Not sure about the 3-4, I really can't get enough speed up for that one while circling my block, after refilling the fluid.

Could be damaged...I'm no expert.

No codes I'm guessing?

Dex 3 isnt outdated so dont worry about that. Its just that gm switched over to dex 6. I know this because when I did my stall I went to gm to get new fluid. They told me they dont carry that anymore and its all dex 6 now. So thats what I used.

As for the trans slipping I would originally say its because you lost fluid. I have been .5 qrt low before and ended up bouncing the limiter at wot.
BUT if your sure that the fluid is correct then who knows.
I will tell you one thing though. When I did my yank ss3600 I under filled it by like 5 qts. I drove it for 10 miles at full operating temp. It was even sizzling and gurgling. The converter was slipping and loose as hell but I didnt know if it was normal because it was first time driving a high stall tc.
I brought the fluid to the correct level and the trans has been fine. I put 10k miles on it with maybe 50 track passes. Still fine.
I have a hard time believing your trans got damaged by driving across town only .5 qrt low.