Thread: what will 1 quart of the wrong tranny fluid do?

I have to assume it's the wrong fluid, but very likely a type for an old gm vehicle I uswd to own.

Tranny started shifting hard about a year ago (1998 GP GT). Currently 190k. I basically kept it near home, changed fluid and filter, no change. Still runs pretty fine, it just hesitates between the last 2 gears. Up to 40mph it revs beyond 20000rpm. Between 45 and 40 it gets closer to 30000. Then shifts. Not a lot of thumping, but I don't fo far. You can nearly always smell burning tranny fluid to some degree.

I'm about to put a quart of Lucas Trans fix, but couldn't pump out some with my hyper tough drain pump. Maybe I had the tunes mixes up lol.

Anyway the Lucas may just prolong the agony. Not even sure if I should bother, as I giving serious thought to pulling the tranny out of a Venture I habe with a bad motor. But was wondering if I pulled out an addirional quart, and dumped the pennzoil fluid with the missing label in, is there a possibility I'd make things much worse? Or just regular worse? Or no change at all.

The fluid tjat's in there doesn't look new anymore. It's nowhere near hershey"s syrup but it ain't candy apple red anymore.

The trans originally called for Dex III. I've replaced my trans and used Dex VI and have had no issues other than high mileage. If you keep it in "3" does it seem to shift ok? If it shifts ok try bumping the shifter into "D" once you are over 45mph sustained. Based on what you posted it sounds like the 4th clutch hub might be toast.

I tried that today. I cam't say nothing has changed, but nothing is fixed. The car seems to rev higher, not quite 30k rpm, when between 40 and 45. The last shift up to 50 doesn't cause it to go as high as before. Mayne only a little above 20krpms.

To me ot seems fluid isn't circulating the way it's suposed to. Sometimes turning the car off for a minute then driving again registers an improvement. It would suck if this were a real simple problem and I was just too obtuse and just assumed it couldn't be fixed.

No one has tried to answer my original question though.