I just today changed my Tranny fluid/filter/gasket on my '90 Camaro. Transmission worked fine before.I drove it home (about 15 miles) and down the street to wall mart. On the way back, there was a clunk, and I lost overdrive. 1,2,D still work, but overdrive works like neutral.

This is a common problem I see, but I can't find a definitive answer on this. Could I have messed something up when dropping the pan and replacing the filter? Or is this just coincidental and means a rebuild?

 

does the tc lock up?

 

I'm fairly certain it does. It did drop when i was in "D" at speed

 

I've read that sometimes, on transmissions with many many miles, when you switch out the fluid, all of the little particles that made friction around all the parts were the only thing holding the tranny together.

Now without the additional friction helping out, you'll start losing gears and such. Imo, it's time for a rebuild.

If you have a service manual (an invaluable resource) you can order a rebuild kit online, and do it yourself. That is what me and my uncle did, and everything turned out great.

Just make sure to have another car to drive while you do this.

 

I had a similar situation. I didn't lose overdrive, but after changing fluid & filter, I now have slow shifts between gears.

 

I called a Chevy Transmission specialist my grandfather knew, and he said it sounds like some stuck valve or something gunked up. He said to take it to speed and mash it a few times.

I took it out on an access road at about 50 in D (OD still Failed) and mashed it 3 times, then put it in OD and it caught and drove alright. Even from the next stoplight it accellerated just fine in OD.

However, now I have a new problem. It drives fine, but when I come to a stop in "clunks" down from 2-1 in OD, and scares me because it feels like i got bumped by the car behind me. It does this 75% of the time. I heard this being normal in D but not in OD. How would I go about fixing this?