RRXJeeper71

is it necessary to drain and refill a few times to really remove all the old fluid and get fresh new fluid through entire system, vs a shop using a forced flush system?
my xj has 96K, bought it 4 years ago with 81K I haven't really driven it much, sits a lot

jordan96xj

Yes. And it wont remove all the old fluid. Each time you do it you'll have more new fluid and less old fluid. But because the two are mixing between every drain/fill its a bit of a math problem to say how many times it would take to get the majority of the old fluid out.

For example, if the old fluid was contaminated and really need to be totally removed. I don't think drain/fill would be cost effective, or effective in general.

But if keeping well maintained fluid in good condition is the goal, than drain/fills work well.

BruceB

If you are using conventional Dex/Merc and want to use synthetic can you still use the drain fill method? Does mixing conventional and synthetic produce any problems or is it not advised?

cruiser54

Np problems.

BruceB

thanks Cruiser!

tech

No mixing conventional and synthetic trans oil is ok they will not cause any problems . I'm doing the same , I'm on my 2nd drain and fill using synthetic trans oil .

Parker Scholz

You should be fine. I put that shaeffer's in not knowing what was in there before and it shifts alot smoother. Im going to drain & fill once more to dilute the old stuff some more.

Parker Scholz

In case anyone was wondering, it's now been 3 years and I still have that fluid in there. Odometer is at 248,000 now (I don't drive very much). Transmission shifts like a dream and the fluid still smells and looks the same as it did coming out of the bottle.