I have a 1994 F150 with a 4R70w (AODE), and until recently it has done just fine.

I won't get into the particulars of why it went bad, other than to say that lending out your truck to a "friend" who has little respect for your belongings is NEVER a good idea...

That said, my truck ran like a Swiss watch when I lent it out. Now, when I put my foot to the floor the engine just spins, like it's disconnected from the tranny.

When I drive it like an old man, it shifts fine, up and down. When I go WOT, the engine just spins and disengages.

I've been told that the problem is probably in the valve body, and that the Electric Pressure Control Solonoid or the Transmission Shift Solonoid have gone bad, or maybe the screens have picked up enough trash that fluid flow has been reduced (easy enough), but before I dig in or shell out any cash, I'd like to hear from those who know this tranny, and have an idea what might be wrong.
Thank you all, in advance.

 

what you describe sounds like an internal failure. have you checked the fluid level? full and bright red?

check engine light or OD light flashing? check for trouble codes?

I would drain the fluid and drop the pan to check for debris.
If you have enough debris to clog the solenoid, the trans is toast anyway.

 

Thanks for your post...sincerely!
No codes, no flashing OD. Fluid is bright red and it's right at the fluid line.
I would ordinarily agree that this might be a "done deal" on the tranny, except for the fact that it behaves perfectly when I drive it gently.
Shifts are even halfway snappy, still.
I do not "love" these trannies (they remind me of the crappy Chevy 4L60 overdrive trannies), and have had other AODE derivitaves give me plenty of trouble in the past--even when well cared for. I much prefer the bulletproof E4OD and 4r100, where, as long as you keep them clean and cool, they operate for a quarter of a million miles (or more) with no trouble.
If I find that the tranny is "toast", I will most certainly be looking for an E4OD, or a ZF5 manual.
Thanks for any additional info you might have.

 

How will you get the E4OD to work in that truck? The computer only knows how to operate a 4R70W, it isn't going to be able to do anything with an E4OD.

 

The E40D did come in the 94 F150 because I had one. It was a SWB F150 XLT 4x4 with a 302 V8. It was a reliable truck. I traded it for a 2000 because of the wind noise on the interstate and the tendency for the front tires to cup which is characteristic of the dual axle design of those models. Ford cured those two issues with the 97 and newer models.

 

You could put a E4OD in it - you would need a computer for a E4OD truck, appropriate wiring harness, driveshaft, etc.

 

You are correct that I would have to get a computer for the E4OD, but I would either continue to run the existing computer for everything else (as many folks do), or just attempt to use a new MAF/E4OD computer for everything.

Currently, I'm hoping to just rescue the 4R70W at this point. I dropped the pan yesterday, changed the filter, and refilled with Merc V. It seemed a little happier, and I am now thinking I have trash in a screen somewhere, as I got it to "hook" a couple times under WOT. It's still not wanting to play nice, but it is definitely improved. I think I'm simply dealing with wear and infrequent maintenance, so typical of hard working machines. Still, I'd like to hear from anyone who's had similiar symptoms.

 

Bump?
I'm beginning to think, through some research that I've done on-line, that my issue might not be in the transmission itself, but perhaps a faulty MAF (Mass Airflow) sensor, or perhaps a faulty VSS (Vehicle Speed Sensor).
My truck popped codes for both, but I did not see the connection at the time.

Anyone have experience with this?

 

A bad VSS can confuse the computer big time.

 

Thanks for your post. At $22.00, it seems like an easy potential fix.
We shall see!

 

Let us know how it works out.

If it has to be rebuilt, there are companies that can beef it up. A coworker here in FL had his 94 Chevy trans rebuilt by Monster.

 

I replaced the VSS and shifting got a little better. It will now kick down at 3/4 throttle, but not WOT. The engine comes out tomorrow for a freshen up (new timing chain, oil pump, water pump, bearing check, re-paint and gasket replacement, etc.), so I'll have no opportunity for a test and tune for a week or so, but the VSS was not the magic fix, so I'll replace the MAF and see how it goes. Then into the valve body to replace and/or fully clean the solonoids and screens. What I'd give for a ZF5 right now! Damn, I love manual trannies...so easy...

BTW, I found a guy who is a good friend of a good friend, and he's already told me he'll do a complete rebuild for $400.00 if I supply all the parts, which ought to run me about $200.00.00-600.00, depending upon whether I go with a new converter, SFI approved flexplate and valve body mod. At that price, I might just go for it, because he does good work, and nobody else on earth is going to give me the same deal.

Thanks for your interest.