Maybe you need to type more carefully, because that is not what you're making it sound like. The op here seems to be a novice mechanic and that could easily steer him in the wrong direction.

 

the front and rear seal are the same as older torqueflites ( 727)that use dexron and they run and last for years....The poster has described a leaking problem, not a shifting problem....Let me be clear, IF he has dexronIII with the additive that converts dexron to atf4, that DID NOT cause his leak....In my OPINION he can use straight up ATF4 and the leak will be the same..IF he did not get dexron and the additive then all bets are off....I would advise to ask "bobistheoilguy" or any manufacturer of dexron oils and ask if it is destroying seals...

Thanks for listening !

 

o boy, wheres master_tech when ya need him?

i dont think the wrong fluid would cause leaks that fast on its own, but i agree that getting ATF+4 in there should be a priority. That said the shop had it, unless you can be certain that they did not do a system flush on the trans i would suspect that they did that, and whatever chemicals and high pressure those systems use are notorious for blowing out seals and causing leaks.

 

Any tranny shop that rebuilt a 44/46re and put dexron in it can tell you how many trannys they had to warantee before they realized how bad it is. Typically on a FRESHLY rebuilt tranny if you put in dex/merc it will last only ~20k better yet one with 100+k on it. Although the seals are mostly likely the result of a pressure flush. The only "flush" that can be safely done is not a flush at all. It simply exhanges the fluid by using the cooler lines. As the old fluid pumps out it pumps new fluid in at the same pressure into the return line, usually a few quarts at a time. The key to the life of these trannys, talking 44/46re(or rh) is to be vigilant on changing the filter and fluid every 30k and adjusting the bands.