My mom's got a '91 Bronco Eddie Bauer with a 351W and the Auto with overdrive. It went out last year and would like it back out. The Trans went by it acting like it was in neutral, but in drive or reverse. 4WD and Low would do the same thing. I would just like to know the best sources for a good transmission, and how bad it is to do a driveway swap. The car itself has only 87,000 miles on it.

 

First thing you'd need to identify is whether or not you have an AOD or an E4OD.

This thread does a good job of helping you figure that out:
https://www.ford-trucks.com/forums/1...ifference.html


I'm not sure what the best source is for a new transmission, but from what I've read/heard, if a deal online looks too good to be true, it probably is.
Another thought is to have a local shop rebuilt it.
Lastly, you can find one in a junk yard and have it looked over.


Swapping out an automatic is really quite simple. When I converted my automatic to a manual, I had the auto out in only a few hours.

Unbolt the transmission from the crossmember. Remove the upper and lower bolts on the crossmember and remove it. Depending on your rust level, soak the bolts in lots and lots and lots of PB Blaster first.
Drain the transmission of oil.
Disconnect the front and rear driveshaft from the transfer case.
Disconnect the shifter from the transfer case, if it's a manual shift.
Unbolt the transfer case from the back of the transmission and remove it. It's held on with six bolts. If it doesn't come off, give it some love. There's nothing else holding it on. (Note that they are separated and do not share oil, so nothing will pour out).
Disconnect the oil lines going to the transfer case.
Remove the bolts that hold the transmission to the engine and remove the transmission.
Reverse to install.

Only thing to note is that the transfer case, and especially the transmission, are HEAVY. Get a transmission jack and make your life 100x easier. I got a decent one at Harbor Freight for about $100. Plus, the jack has a strap to wrap around and stabilize it, so it doesn't fall.

The Bronco has a lot of room to work underneath, so it's pretty easy getting to things.
Just be ready for lots of ATF getting every where. I trained my transmission and lines, but the torque converter holds a lot, and likes to keep draining.

 

Does it still hold in park, or does it roll? If it rolls, the problem is in the transfer case. If it holds, it's the transmission.

 

yes, it holds in park.

 

Then the transfer case is working and the transmission is not.

 

What kind of tans fluid should go in it, and I should change the t case fluid too, what fluid for that?

 

Also, I have an E4OD.

 

The transfer case and transmission are separate, so you don't necessarily need to change the T-Case fluid unless you just want to be on top of it.

But, both just take ATF.

Ford does makes a specific Transfer Case Fluid, but most say they just use ATF and never have an issue.

 

That's wrong. The transmission takes MERCON V ATF. There are many, many other ATF specs that will destroy this transmission. Do not use any old ATF.

 

Yes, you're correct. My apologies, as I worded that incorrectly. I didn't mean they take ANY ATF, I just meant that they both take ATF (without specifying which kind).
Poor wording on my part.

 

Have you checked the transmission fluid level?