2nd Gen 5.0 with 5R55E?

[compworks]

Howdy, all! Haven't posted on here in a while, but I'm back.

Now for a little late-night absurdity: what do y'all think about replacing the 4R70W auto trans in the 5.0 Explorer with the 5R55E from the 4.0? I'm considering it as a project for my next vehicle, and since I accumulate a lot of city miles, I figure the extra cog might help with fuel mileage.
I've done a little research that suggests that the 5R55E would bolt up to the 5.0; I know computer issues are another story, though. I haven't seen any evidence that such a swap has been attempted, much less successfully completed.

Any advice is welcome, as well as comments that I'm off my rocker. But what's new about that?

 

[vroomzoomboom]

where did you find that it would bolt up to a 5L? i have never seen that, unless you get a adapter plate made. that and i am not even sure the converter would match up to the flex plate. also the starter is on the opposite side

 

[compworks]

where did you find that it would bolt up to a 5L? i have never seen that, unless you get a adapter plate made. that and i am not even sure the converter would match up to the flex plate. also the starter is on the opposite side

I didn't find anything that specifically said that it was possible; you're probably right about needing an adapter plate. And since I'm not a total expert on car mechanicals (haven't ever messed with a trans or engine swap), why does it matter what side of the car the starter is on? Just curious.

 

[vroomzoomboom]

the small issue would be having to move the electrical around to the other side. the big problem is will it clear the exhaust manifold, and pipe.

 

[JK080]

Howdy, all! Haven't posted on here in a while, but I'm back.

Now for a little late-night absurdity: what do y'all think about replacing the 4R70W auto trans in the 5.0 Explorer with the 5R55E from the 4.0? I'm considering it as a project for my next vehicle, and since I accumulate a lot of city miles, I figure the extra cog might help with fuel mileage.
I've done a little research that suggests that the 5R55E would bolt up to the 5.0; I know computer issues are another story, though. I haven't seen any evidence that such a swap has been attempted, much less successfully completed.

Any advice is welcome, as well as comments that I'm off my rocker. But what's new about that?

The 5R55E has a 5th gear ratio of .075.

The 4R70W has a 4th gear ratio of .070.

The real benefit to fuel milage would be a swap of a 4R70W in place of a 5R55E.

I would leave in the 4R70W, its a better tranny anyways and none of the headache of a swap.