Hypothetical - 2.7 AWD conversion considerations

Coming from the Audi/Quattro world, reading that the Manual FJ Cruiser's have a Torsen based AWD setup got (forgive the pun) my wheels turning.

My taco's a manual 2.7, but most of my research so far has turned up info on the 6 speeds/v6's. I'm trying to minimize my assumptions so I still have some things I am wondering about:

1. Do both R155F & RA60F transmissions have the same T-case bolt pattern? (based on what I've read, I'm thinking this is the case)

2. If the bolt pattern is the same, the next piece would be matching the Manual FJ T-case input shafts to the 5 speed transmission (with the R155F having a different number of splines), right?

3. If the T-Case can be swapped in, the rear driveshaft would need to be shortened to accommodate the T-case's longer length. Would the front drive shaft need adjustment too?

Then this is where it really starts to get murky for me

4. Keeping the stock ADD system, and pending the electronics are working correctly, is this feasible?
• 2wd (Front axles disengaged via ADD, center diff locked and sends all power to the rear)
• AWD (Front axles engaged, center diff sends power to front and rear, modulating in real time based on conditions)
• 4WD (Front axles engaged, center diff locked to split power 50/50 front and rear)

This would essentially keep 2wd, add AWD, keep 4High and remove 4Lo. (for simplicity, ADD could be removed altogether by swapping in the FJ front dif/axle carrier, removing 2wd and just keeping AWD and 4Hi)

5. Could this be done with just the FJ Transfer case, a shortened drive shaft, and possibly the FJ Front Diff (if removing 2wd)?

6. What electronic considerations are at play here? (controllers, ecu's, traction control systems etc)

Bonus: Am I totally nuts for rethinking a setup in an already pretty capable truck?



So here is why it's appealing to me in the first place:

• my truck is a daily driver. 98% of the time, it will only see street use. This does include snow though, and Quattro saved my butt many a time in the past.

• I will very seldom use 4Lo.

• 2wd for good conditions preserves my gas milage, while AWD for intermittent/bad conditions (like driving on partly snowy/icy pavement) prevents the need to constantly toggle into 4Hi.


What do you guys think?

 

Your ideas, sound like my ideas.

This deserves the "think differently" bump.

 

You may want to PM Torspd, I think he was looking at the AWD for his Tacoma but not sure how far he made it.