"Unserviceable" tranny leak on 4R70W?

[arkiejim1]

Greetings! I've been reading this forum for years but never asked a question, so I just registered today. I've searched all over but can't find anything that appears to address my issue. '97 F-150 2WD 4.6L with auto tranny...I THINK it is a 4R70W. Started POURING out fluid two or three months ago. Took it to my mechanic...they replaced the seal at the rear of the extension housing. Great for a month or so then started leaking again, so took it back. This time they said it was not the seal but leaking at the rear of the transmission proper and that Ford told them it was not servicable. New tranny required...$3,500. For a '97 with over 200,000 miles??? Not happening! They put the ext housing seal back in and no leak at all for about another month, but now it has started again. Took 5 quarts of fluid to drive 100 miles last weekend to pick up a used stair-stepper my wife found on Craig's List, as it wouldn't fit in our Expedition. This is a second vehicle and she won't let me replace it or spend much money on it. WAH! I LOVE my truck and don't know how I will get by without one! I used to consider myself a pretty good "shade-tree" mechanic, but I've never messed with a tranny before. Plus, I've finally gotten to where I can afford to pay someone else to get their hands dirty. <grin> My question...is it really true that the rear of the transmission body doesn't have a replaceable seal or bushing? Mechanic says there has been too much play due to bad CVC joints or something over the years and it has too much wear. Thanks in advance! Jim Smith aka arkiejim1

[Klitch]

I'm not the expert by any means, so I wont pretend to have an answer.

I will suggest, heeding Darrin Burch's advice, the man knows what he is doing. I have a trans built by him. It handles my hound like a champ, with my heavy foot that scares the hell out of me.

Second I will suggest considering a pull and save option, or a "realistic" priced remanufactured unit if price is the main pull in this situation.