so we rebuilt the 727 in my 81 d150, got her bolted up fired up the truck but only had reverse, so we dropped the pan & the fluid was like pepto, what im thinking is the line in the radiator cracked an water got inside the trans, now am i screwed?? folks said i will need to rebuild it AGAIN??? we left the pan off all night an plan to dump NEW fluid in along with a NEW trans cooler.. is there any thing i should dump in the trans that might help?? i was told dump some lucas in, i knw i might have to change the fluid a few times to get EVERY thing out but am i safe or am i going to have to do a rebuild???

It's doubtful that water inside is the cause of not having forward gears; you have two separate problems, water and distress in the rear clutch.

well pulling it back out & taking it to the builder tomorrow, the trans had a 3 clutch set up.. he put a 4 clutch set up inside so im thinking thats the problem... pulled the valve body an cleaned it an no go...

I had the same issue w/ a trans a while back. Mine got in via the fill tube somehow. I still had all forward gears it just slipped like heck. I drained it at the track and refilled it. It still slipped some. The only way to do it right is to pull the trans and drain the converter too. OR unbolt the trans line from the cooler, start the car, put it in N and run the car until you see nice fluid pumping out. I pulled my trans, drained the covert, dropped the pan, and used a leaf blower to get all the water out...might have been overkill.

We have bought several Neons over the years with broken tranny coolers. We just get as much fluid out with the cooler output line as we can, refill with fresh fluid, run in place for a few minutes and repeat. Usually takes 5 or 6 times before the fluid looks completely red as it should.

As long as the tranny hasn't been driven very long with the coolant in it, the tranny survives. The water itself doesn't seem to do the tranny any real damage. It's the driving and slipping while it is in there that kills it. I don't know of any additive that claims to deal with water ingestion. We don't add any.

I know of several of these cars that are still daily drivers years after doing this procedure.