Transfer case swap. Multi mode 2WD AWD VF3AM + VF4AM

I’ve been following along

unfortunately I used the VF4B in both of my tacos and also deleted the ADD in both trucks so I am not much help. I absolutely love the full time AWD though. It is definitely worth the hassle no matter which case you go with.

I went full manual everything for the sake of simplicity and because I didn’t see a reason for keeping 2wd

 

No, the factory Toyota rear elocker uses electric motor and limit switches. Just my truck didn't come with one. So when I retrofitted the elocker in, I had to buy an aftermarket harness in order to control it. The one in particular I bought was from Dark Illusions Fabrication. Would be simple to have it control a center diff lock instead of a rear elocker.

 

From what I read in the FSM there are only two shift rails in the VF4AM so the locking isn’t a separate motor to control. There are limit switches for the diff lock but it’s for controlling one of the shift rails through three positions

I forget which rail has three positions, but one of them does. So it’s either the 2/4 shift rail that has three positions for 2locked, 4 locked, 4 unlocked, or it’s the H/L shift rail that that has three positions for Hi unlocked, Hi locked, and Low locked.

Either way, the center diff locking is integrated with the shifting so I think you’ll need to use one of the 4wd ecus that can control that shift logic. I think that would need to be either the Sequoia or v6 4R 4wd ecus and then feed them the appropriate control button signals. Sequoia uses three push buttons (diff lock, 2/4, H/L) where the 4Runner uses a rotary knob for 2H/4H/4L and a button for diff lock.

My application is a 2006 Tundra engine ecu so I don’t think I need to worry about the CAN connection because it’s all point to point wiring for the 4wd related controls and signals, but in your Tacoma you might. Or you might need to piggyback and run both as was suggested earlier.

I do need to spoof the ADD limit switches or have an ADD motor wired up and not connected because I’m using a solid front axle. My plan is to live with the front driveshaft spinning in 2wd mode.

 

the hi/lo rail of the full time case controls the center differential lock