Thread: Transmission flush. Yes or no?

The only way to get all the fluid out is to drop the pan, change the filter, put the pan back on, fill with about 15 quarts of trans fluid, take the return line off the trans and stick it in a bucket, run the car until fluid stops flowing, put line back on, refill to proper level, enjoy fresh fluid.

I would just drop the pan and change the filter.

A powerflush from a shop would be fine as well. Anyone that tells you that their trans went out shortly after a fluid change was either having issues already, or the trans was already on it's last leg.

Heres the deal... From everything Ive seen with used cars if there has been (meaning there is proof) that the car has had its trans flushed on a regular basis, then a trans flush is fine. However, If it has NEVER been flushed, do NOT flush the trans as you will literally be flushing out lubed up vital seals and will cause them to fail. There is no need to get ALL the fluid out of your trans as without a flush itd be nearly impossible (like trying to get all the oil out of your engine/SC...).

We have literally had numerous customers accuse us of selling them bad cars due to trans failure when the first thing they do is go and get it flushed...

Always reset the trans or unhook the battery after a flush or pan drop. I'd guess that's where most people go wrong. Nothing magical about old fluid.

this thread is SO HELPFUL was thinking of doing the same

I see some good, questionable and stuff in this thread.

Reality is, a flush doesn't hurt a trans. It replaces the clutch material laden fluid with fresh detergent filled fluid. If there's an issue or odd feeling that is causing you to consider fluid replacement/trans service, then keep in mind you have a pre existing issue. Don't blame a service or flush if things head south.

I do a trans service via pan drop, filter replacement once a year or every 30K miles. It keeps the fluid nice and clean. Doing this service typically needs 6.5-7.5 quarts of fluid. If you leave the pan off overnight, you'll put in closer to 10 quarts. Trans holds 13 quarts when dry. This would mean residual oil, converter, valve body and channel plate are holding another 3 quarts.

All a flush does is run more fluid through the trans to bring the amount of dirty fluid down. It's not that you are totally draining it all and then putting in new, you are pumping new into the old and draining off a good amount of the mixed fluid. Ensure with any flush that a filter is done. And speaking of such, when is the new filter put in? Before and you are still filtering all the old fluid through it, after and you are using even more fluid to do the job.