91 Explorer transmission issues.

[JohnB33]

I bought a 91 explorer and on the way home the check engine light goes on and off and the trans starts slipping to a complete loss. I checked the codes and it throws: 89 and 86 in that order. I figure typical failure and the codes are just representing this. What my question is , their is a three wired plug end on the drivers side. The plug was not plugged in. When I plugged it in it blows the EEC relay fuse. What does this plug control on the transmission? Seems I have a bad wire somewhere. I did test drive the vehicle a few days before purchasing and noticed the trans slipping. Just curious of what this plug controls. I havent had the chance to pick up a chilton on it yet. Thanks John

 

[MrShorty]

KOEO 89 and 86 indicate a fault in the 3-4 shift solenoid circuit and TCC solenoid circuits. That three wire connector is for those two circuits. The fuse blowing is probably due to a short in those circuits inside the transmission (probably a wire that got pinched or worn through). So, those two codes are from the circuit fault (either unplugged or the short).

One thing I would note, is that neither of those circuits has anything to do with the transmission slipping. On an A4LD, those circuits only control the timing of those two shifts. The slipping is from some deeper mechanical/hydraulic issue.

 

[JohnB33]

I knew the trans was shot. Just curious as in the actions of the wires. Thanks

 

[JohnB33]

So is the 91-94 trans the only one that will work in my 91? If not what years can I use? Thanks John

 

[FordFreak89]

Check these

If your tranny is slipping check your trans fluid. You might want get it flushed. It would help to know when it was last serviced and if it does it all the time or just certain gears.

 

[JohnB33]

Im not debating if my trans is broke. I wanna know what years will interchange with it. Ive owned it all of like 3 days. The tc looks to be messed up also. I pulled the trans today.

 

[FordFreak89]

just sayin it would help with the diagnosis and fixing

 

[JohnB33]

Thanks

 

[MrShorty]

So is the 91-94 trans the only one that will work in my 91? If not what years can I use? Thanks John

How best to answer this?? I would say, yes, only use an A4LD from a 4.0. Technically, an A4LD from an '88+ 2.9 L will also bolt up to your 4.0 with the right electrical configuration, but the 2.9 L A4LD isn't built as strong as the 4.0 A4LD. A 2.9 L A4LD can be rebuilt to 4.0 specs, but, since I expect you are trying to avoid the rebuild part, I would recommend you stick with locating a 4.0 A4LD.

 

[92exp4x4]

They used that trans up to 96 or 97 I think. MrShorty is correct. Even with the transmissions being the same, the cases are different for each motor. Ford did the same thing with the manuals too. You will need one from a 4.0 truck. Look at rangers and aerostar vans too.

You could consider swapping a 5 speed...

 

[Mettler]

This guy kinda has the same question that I was thinking about. Will a 5R55 work on a first gen?

 

[MrShorty]

My impression is that the 5R55E from behind the 2nd gen 4.0's is very similar in boltpatterns and dimensions to an A4LD. The main issue I see is the electronics -- the 5R55E is all electronically controlled where the A4LD isn't. Someone sells a stand-alone controller for the 5R55, but it's quite expensive. If one were willing to spend the money for the controller, my impression is that this would be doable.

Alternatively, you might look at the Frankentranny thread in the transmission forum. They talk about how to rebuild an A4LD using some 4R55E/5R55E parts to get past the weaknesses in the A4LD. Glacier's A4LD rebuild diary thread also mentions some of these upgrades/improvements.