NP 231 to 4R70W (Or AODE)
Derrick1970:
I struck pay dirt!
While searching for someone with the AODE to Dana 300 adapter available; I wound up contacting Kris at NorthWest FabWorks,
http://www.northwestfab.com/.
He wouldn't sell me an AA solution but rather a NWF solution:
For a little under $300 including shipping and taxes, Kris sent me a replacement input shaft for my NP231 (or NP242 in my case).
Note 1: Your NP transfer case needs to be post '95 to have correct gears
Note 2: Your NP transfer case needs to have 6010N input shaft bearing.
With input swapped - transfer case has to come almost completely apart - the transfer case now bolts to my 4R70W.
So, for less than 1/2 price of the AA - AODE to BW1354, I had a solution. And transmission didn't have to come apart (I feel comfortable rebuilding transfer cases; automatic transmissions - not so much), so add some additional savings. Sold the Explorer's BW4404 and Ranger's 1354 for more than price of NP231.
Note 3: 4R70W needs to be 4wd/awd model.
I splurged a little on the NP242 (output shaft solutions/6 pinion planetary), but the rest of my truck's drive train wasn't stock and I needed to do something about that anyways.
NP transfer case is same width as BW1354, so easily fits between rails of Ranger.
NP transfer case low ratio @ 2.72:1 is just a little lower than BW1354s of 2.48:1. (Really close to the 2.69:1 of the BW1356).
Sprockets in NP231 are ~40% larger than those of BW1354; technically same size as those in 1356 (I know BW1354's rarely fail from load, but extra capacity doesn't hurt given the 331 under hood has ~50% more torque than 4.0 did/4R70W 1st is lower than 5R55E/Low ratio is lower - max torque is almost double).
Don