Hey all, Have some big time questions about my 3s auto trans fluid. My car has 114k on it and i last changed the trans fluid at about 50k. Now lately I've been told when going to get oil changes that my fluid is really dark and needs to be changed. I learned from this forum that 3s have notoriously rough transmissions so i don't want to let this go. Here's where my series of many questions come into play. First off has anyone done a fluid change themselves? I really don't have the money to pay $100+ at a garage. this brings me to my next question...i've done some reading and some garages use pumps to ensure they get out all the old stuff and put in all new stuff. With an older transmission does this technique run the risk of knocking out some sludge or shaving and wrecking my transmission. If i were to do it myself my plan was to simply drain the old stuff..if there is a single plug like some cars....and replace it with new. Now i know this doesn't truly get everything but i figure newer fluid has got to be better then old dark stuff even if it's not totally flushed. I guess my final question is..do i leave it alone? I've heard some talk that on old cars if the transmission isn't doing anything funny leave it alone. I'm just so nervous that the fluid will break down and i'll ruin the whole thing by taking this route.

Sorry for the long post but I know you guys know your stuff

Thanks.

 

I can't comment much on the ATX since I have a MTX. Doing a drain and fill should be fine. If you wanted to get more of the old stuff out do a DnF, drive for a week and then do another one. Unless there's an issue with the old fluid I don't really think a flush is necessary (I could certainly be wrong though).

I certainly wouldn't just leave the transmission alone because you think changing the fluid will break it. The transmission fluid is supposed to be replaced. It's oil and gets both dirty and broken down and eventually doesn't do it's job as well. I've had two transmissions die on me while on the interstate (both in cars that didn't have regular maintenance such as transaxle fluid changes) so I'd suggest it.

Changing it is pretty easy on the MTX..... drain, replace plug, remove fill and fill until it pours out the opening. In the ATX I believe there's a filler spout in the engine compt. I imagine draining is the same way.