4R70W 4x4 or 2wd Does it matter?

[Twidgeon]

I'm looking into doing a explorer/mountaineer swap. Does it matter if the tranny comes from a 4x4 truck or 2wd?

 

[Nickm1024cobra]

Both will work. I believe it only matters when ordering the AA Adapter. 4WD trans you have to cut the output shaft on the trans, 2WD you have to change output shaft.

Cutting is easy, not sure on the changing of the shaft. Hopefully someone else will chime in and correct me if Im wrong. I had a 4WD trans and cut maybe an inch from the output shaft.

 

[sykanr0ng]

The tailhousing on a 2wd is different from the tailhousing of the 4x4.

You would need a 4x4 tailhousing to bolt to the adapter or transfer case.

 

[Broncobowsher]

Different tailshaft between 2WD and 4WD as well. Total transmission tear down to change that shaft. It is literally the first part to go into the transmission when building one.

 

[sykanr0ng]

Different tailshaft between 2WD and 4WD as well. Total transmission tear down to change that shaft. It is literally the first part to go into the transmission when building one.

/\/\ That too.
So you buy the 2wd 4R70W, buy the 4x4 tailshaft housing, buy the 4x4 tailshaft and then since you have it all apart and you are replacing the seals anyway while you're at it rebuild it.

 

[Twidgeon]

Thanks everyone!! That's exactly what I needed to know. There's a 4wd mountaineer and a 2 wheel drive explorer I'll be checking out this coming week. Hopefully the mountaineer is in good shape.

 

[wsager]

I thought that you used the ZF Advance Adapters adapter for the 4x4 4r70w, for the 2wd you use the 4r70w AA adapter (comes with tailshaft and housing). The 2wd is shorter, but costs about $100 or 150 more and requires the trans to be disassembled.

 

[Broncobowsher]

2WD is not shorter. From the bellhousing to the tailhousing flange both transmissions are identical. The 2WD output shaft is actually longer as it is the slip yoke is part of the output shaft.

 

[wsager]

2WD is not shorter. From the bellhousing to the tailhousing flange both transmissions are identical. The 2WD output shaft is actually longer as it is the slip yoke is part of the output shaft.

Even after both are converted?

 

[sykanr0ng]

2WD is not shorter. From the bellhousing to the tailhousing flange both transmissions are identical. The 2WD output shaft is actually longer as it is the slip yoke is part of the output shaft.

Even after both are converted?

These are the output shafts, the AA adapter adds a piece to the splined end of the shaft:

 

[sykanr0ng]

Another thread on this:

http://classicbroncos.com/forums/showthread.php?t=251312

 

[fordguy]

do you plan on running the dana 20

 

[Broncobowsher]

Even after both are converted?

From the tailshaft mating flange forward, no difference. (tailshaft sticks out behind the mating flange even though it is installed from in front of it)
The actual transmission case itself, from the bellhousing flange to the tailshaft flange, is exactly the same in 2WD and 4WD.

Now how long the different adaptors are, I don't know. I lost track at somewhere around 3 different ways of doing it.

 

[Twidgeon]

Yeah sticking with the Dana 20. I really haven't looked into the explorer/mountaineer transfer case.

 

[bronconut73]

Yeah sticking with the Dana 20. I really haven't looked into the explorer/mountaineer transfer case.

Well.....you could also bolt an NP-205 to that tranny with no adapter.

But it's a "big" transfer case

 

[Twidgeon]

Dang it!!! That's all I needed was more options What trucks have the NP-205? As far as the transfer case mounting goes, is there any need to alter the cross member?

 

[bronconut73]

Dang it!!! That's all I needed was more options What trucks have the NP-205? As far as the transfer case mounting goes, is there any need to alter the cross member?

If you want to run a NP-205 then do a classic bronco "Google search" you will learn a lot.

The 205 is very strong but not geared too low. It is big and will typically cause you to run your exhaust down passenger side.
But many have made it work very well for them.

You would see them in the 70's and 80's maybe even a few cab and chassis trucks well into the 90's. A lot of 70's trucks also had 203's and 208's....you don't want those....well maybe the range box off the 203 but that's it.

So....205 is great....but in regards to the crossmember..... it ain't a bolt on. Might be worth it to you though. Check into it. Lots of info here at CB on it,

 

[Broncobowsher]

If looking at the NP205 not any NP205 will do. It has to be a Ford version. Driver's side drop, others put the front driveshaft on the passenger side. Needs to be married, not a divorced transfer case. Last I knew they were only used '73 to '79. '80 is a whole new truck and everything changed.

 

[fordguy]

Yeah sticking with the Dana 20. I really haven't looked into the explorer/mountaineer transfer case.

both 2wd and awd have to be converted for dana 20. AA is one route, and the Zf adapter is another route. Someone mentioned a third, but I don't know that one. AA has everything in one kit. I had the 2wd and used the AA kit, but have sold that transmission. I now have an awd that I am going np205 on.

 

[fordguy]

the np205 will complicate things. completely new cross member will be needed. stick with the dana 20.