I recently replaced the trans filter and fluid in my 98LT.
After doing so it seems to slip in certain driving ranges but not all the time. When replacing the filter I matched the old with the new at the auto parts store. Also,how far up into the seal should the filter go?

 

The filter should go on until the body touches the valve body. Make sure it's not against the switch or the pan will not go on... unless you want to break something.

First check the fluid level with engine running and in Park. If you have to add some,do so and take it for a very easy drive so you make it through all the gears a few times. Check it again to make sure it is still full.

I've learned my lesson the hard way and I now run the vehicle with the drive wheels in the air after a filter change or a transmission install. I end up putting in less fluid than required the first time and end up having some situation like that happen almost every time.

 

This really only seems to be happening when I turn right or left at highway speed.
I checked the fluid level in park while running like you said but I seem to be getting an inacurate level while running ( looks like its over filled) but when i shut it off and let it sit for about 10+ minutes and check it it shows that it is on the line.

 

You have me stumped right now on this one. The only thing I can think of off the top of my head so far is that it may be just a bit low causing some foaming so it reads overfull while running.

 

Slipping while turning on the highway suggests the problem is related to sloshing in the pan. It should read way over filled when the engine is off. Sounds like there is some foaming going on while running, as TZ said. Add 1 quart of transmission fluid and drive it GENTLY to shift through all gears. Then park it and check the level again with the engine running. If it is still reading high while running and correct or slightly higher when off, I too am stumped.

-William

 

I will do as suggested and put in another quart when the Wifey gets home tonight from work and post results for everyone.
Thanks alot to everyone for the help,now to fix this darned hot/cold air thing ive suddenly obtained.

 

Turns out you were right I was 2 Qts low.

 

As long as you took it easy you should be ok. 3rd gear clutches are very picky about line pressure and the slightest drop under load will leave them burnt and worthless.

Don't worry about it. I've had something similar to that happen about 3 times already on 3 different vehicles.