Hey guys, I am taking a look at a friends car and am a complete tranny noob,so any input is welcome.

I believe it is a 4R70W, though I am unclear on the difference between that and the AODE.

So here's what we have going on:

The problem started several months ago, when he tried backing out of his house and the truck went forward instead. He said the the days leading up to this he noticed an unusual sound coming from the tranny (unclear on what kind of sound).

He brought it over the other day and what we have are the following symptoms:

1) what sounds like a rattling from the torque converter
2) The truck going forward in all manually selected shift positions other than park and reverse.
3) Reverse does not move the vehicle (though when the problem first presented itself, he reported going forward in reverse)
4) When driving, it does not appear to shift out of 2nd

I haven't had time for anything other than a preliminary examination, and am hesitant to do more than that without a little more research done as I have never been inside a tranny. The fluid color and smell are normal, though it is very much overfull (yes, checked withe engine warm and running). Manually moving the manual shifter yields the same result (i.e. shift selector cable disconnected)

How to proceed?
With the small amount of understanding that I have here, my thoughts are:
1. Limp mode? but why?
2. Valve or solenoid stuck?
3.Bad MLPS?
4. Forward clutches fused together?

Beyond that, I really don't have much of a clue. How can you help? Tell me how to proceed in the troubleshooting process. How do I narrow it down?

Thanks for reading!

 

The fact that the torque converter is making noises makes me think that maybe the pump is being affected by that, but why would that lead to going forward in neutral?

 

I am not well versed on the ford transmissions, but i once had a gm th350 have forward in 1-2-3 and neutral. It was due to a bad forward clutch pack that had friction welded itself. So it couldnt slip when the apply piston released, giving it forward n neutral. However, it would not go anywhere in reverse since it was trying to go both directions at the same time. Basically a poor mans transbrake lol.

 

what motor, 2wd, 4wd, what is trans code on driver door jamb

 

1. No. 2. No. 3. No. 4. Yup.

Take it out and rebuild or replace it.

 

It is a 302 4wd. I am out of town and can't look at the door jam at the moment.

 

Can you tell me why you think that? Any way to verify it is not something else before pulling the thing apart?

And if the clutches are welded together, would it stay in gear without hydraulic pressure? With the engine off, I can move it as though it were in neutral.

again /noob here

 

Because NOTHING but a welded together forward clutch can cause it to still be in gear when in neutral.

Yes, there is! Run this test: Put the trans in neutral. If it drives forward the forward clutch is welded together and the trans needs to be rebuilt or replaced. NOTHING else can cause this.

And if the clutches are welded together, would it stay in gear without hydraulic pressure? No, it also needs other clutches to engage. Once the engine is off those release and you can roll it.

 

Ha! What a snarky reply! Thank you for the info.

 

I dont think snark was intended, I think he was trying to save a lot of useless chasing of issues, judging by the credentials.....
"Mark - Former Ford Automatic Transmission Engineer 1988 - 2007"

 

In college, I minored in snark.