Changed oil & filter in AOD and trans started to slip after the change?

slvrchvy1 · 07-26-2002

Hello! I have a 1990 mustang GT, and my problem started when I changed the transmission oil and filter. The trans started to slip after the change, when before it shifted great. ( note: the trans oil was changed because it was old and dark brown.) Now, it got worse, if I shift from PARK to OD it does a loud CLUNK! and shuts off. But, if I shift from PARK to 1ST quickly it stays on, I just have to work the gears from 1ST to DRIVE. ANY ANSWERS???????? Thanks!!!!!!!!!!!!!!!!

Vortex · 07-26-2002

Not to sound like a smart@$$, but did you put enough fluid in it? some people dont check it with the car running. If you put a new filter in, it shouldve gotten better....
again, not to undermine you. I dont know how much you know about cars... just citing the first thing that pops in my head.

slvrchvy1 · 07-27-2002

Thanks for the tip, But, yes I did check the fluid and its ok.

**74stang2togo** · 07-27-2002

There's a funny thing about automatic transmissions. They seem to be tempermental. I had the same problem with a Chevy Suburban. I seem to recall the filter having come back out and messing up the fluid pressures in the trans. this resulted in screwy shifts and other problems. If you have the time/patience I would drain it again, just to double check the filter. I know this will be problematic (have to get new fluid and gasket again) but it may be the answer to your problem.

fvpnt0pony92 · 07-27-2002

did you check the fluid after running it through the gears for a while because after doing this the fluid level may drop and youll have to add more. this is what it sounds like to me anyway.

just make sure not to overfill it!! this will make your tranny very upset with you!!