OK...this is my first post here...and its a BIGGIE.

I have no clue to the solution to this...$1600 bucks later...
...and Im really, really, really ticked off about this.

I'll try to keep this short and sweet...but my frustration with this whole situation is making it difficult...so excuse me if I run on with this a bit...its tough to keep it short. I truly need some people who really know about E4OD's and what causes these problems...or personal similar experiences and what the solutions were.

That said....

Specs....1991 Bronco 351 E4OD 107K miles.

I noticed some slight "seat of the pants" slippage in the trans in October.
I changed most of the trans fluid....7 quarts...put in a new OEM filter.
No difference.

There also was an ever so slight whining...normal to some cars...a Jeep I had for years always had a very slight tranny whine and it never mattered...but this trans had NO noise at all previous to this stuff happening

So...
Tried adding 1/2 quart Lucas transmission additive....
No difference.

One night...I pulling into into a parking spot at a restaurant...the trans feels like it slipping like crazy and won't shift correctly from 1st gear into the other gears...1st to 2nd shift mostly...it slipped a lot. I felt something was definitely wrong with the trans....and unfortunately I pulled the truck into a position where I had to backup to make a turn....that was it...I couldn't back up. Now I was screwed. It was as if someone was holding the brakes on as I was trying to back up. The engine revved up normally...but no go...PERIOD. ..just like the brakes were locked. I couldnt backup...AND I couldnt go forward since I was blocked by other vehicles. We couldn't even push the thing backward (and no...the parking brake was not on)

Bottom line here....I had it flat-bedded to AAMCO trans.

I explain to the guys at AAMCO...the symptoms...and what happened....they call a couple days later and said its rolling fine right now. I told them it was definitely screwed up and to find and fix the probem. If it has to be rebuilt..fine.
They call back a couple days later....they say it needs a rebuild...OK...fine. Done.
So they rebuild it.

ONE WEEK after getting the truck back...and thinking it was fixed.... the problem comes back...only worse.. and with new problems.
Now the truck still will get stuck trying to back up in reverse (if you give it the opportunity...so I always face forward)...and now....when I come to a stop... running on a highway for a short run...maybe only even 3-4 or 5 miles...the 1st gear shift slips like nothing was ever fixed...just like it got that night when it locked up this very first time and I had to have it towed.
Now it also slips 1st gear until 2nd gear...maybe even a bit of 2nd gear too... just like it did before I pulled into the parking lot that night. Once 2nd gear kicks in...then it SEEMS to run fine on throught the rest of the gears...Im not even sure about this anymore. It still acts as if if the brakes were locked...it seems less so when it is cold...and I KNOW for a fact the actual brakes were/are working perfectly.. (all new hardware...drums...cylinders... everything. No old parts....even the brake cables)


...PLUS...(but wait...there's more)

Now my 4wd tranny whines when it is in gear...Hi or Low Range....and it NEVER did that before...plus the engines stalls out every 3rd or 4th time I try to backup....(assuming it will back up anyway).....oh yeah.....and NOW when you shift it into reverse...and it does actually backup...it "BANGS" bad...usually one hard bang....like I got hit from behind at 5 mph or something. Its nasty and scared the crap out of me the first time. I thought I hit another car!

NOW...I call the AAMCO guys back....tell them the problem is still there...take the truck back to them...and now...(in a nutshell version for here)...they are now telling me after 3 days of looking at the trans AGAIN that the rear end is shot...and that is causing the transmission shifting problem. Somehow it is "fooling the electronics into not working correctly". He was saying there were some type of sensors not working correctly.

I DONT BUY THIS...there are no sensors on the rear....possibly the output shaft has some type of sensors....but I know there are none in...on...or around...the rear-end of this truck.

If the rear was actually toast...it would whine...grind or do something noisy on a constant basis...or not move at all in ANY direction ever....and it doesnt. In my book...if a rear is dead...you know it for sure. There is no in between.
I thought about testing this with dropping the rear drive shaft and running in "front wheel dirve" mode and try backing up..to see if it locks up again...bt that is a pain in the butt...and I dont have time for that....but I dont know any other way.

The main issue is.....what is REALLY wrong with the tranny...and how do I fix it? I am having my doubts about these AAMCO guys and their sincerity and actual knowledge. BUT....I DO have a 12 month/12K warranty from these guys.... and I want to be armed with some good information when I go in there this week and twist their arms behind their figurative backs and say FIX THE FREAKING THING RIGHT.

So....fellow message boarders....Gimme some help PLEASE!......info...thoughts...whatever....etc.

I know most tech stuff about about cars and trucks and can do a lot of things myself...but transmissions I know next to nothing about in terms of how their guts actually work together and how one part interacts with the other one.
Tearing down the trans myself is not an option.


SOooooooooooo....

HEEEEEEEEEELLLLLLP!!!


Thanks everyone.

<---this is for whoever can answer this


CiscoKiDD