What kind of transmission fluid goes in a 1990 Pontiac Bonneville & what kind of

Head down to your local parts store, I prefer CarQuest. Ask for a Transmission Filter Kit, Grey Silicone (Sealant), and regular DEX/MERC transmission fluid. 6 quarts should be enough. u should spend somewhere around $30.00. And u just performed a professional automotive repair.
 
probably Dextron. owners manual or parts store could tell you.

I don't remove trans oil pans anymore unless they're leaking. I've never seen a clogged filter, except in a ruined trans. If you want to flush trans fluid , Try this :

Auto trans fluid is pumped thru the radiator (seperate cooler inside). Remove either of the hoses and point it into a bucket. put a hose on the fitting you took it from, and point it into the bucket, too. Weight them down, one of them will spray like a garden hose.

start engine, run it until fluid stops spraying. add 2.5 or 3 quarts and repeat. after about 11 quarts, fluid coming out will look new. Make sure to use the right kind of ATF- owners manual. No need to put it in gear.

The transmission has a built in pump. even when it stops spraying, its still plenty oily inside to not hurt anything. I've done this dozens of times
 
Back
Top