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

My research into swapping an AWD transfer case has been ongoing for a couple of weeks now. Lots of thank yous to those that have done various swaps over the years, and supplied the information! So... The choice has been made, and unless someone introduces some info that will outright show/prevent the swap as being unviable, the Multi-mode VF3AM version is the one. It has 2WD, AWD, 4WD, neutral, and low range. Given that the unit has both an electronic actuator and manual shift stick for the various operations, it should integrate and play very nicely with the stock electronics in the Tacoma... Still interested? Read on....

The stock transfer case is a good ole' VF2A that has complete electronic control over the shifting. The VF3AM, as mentioned above, uses electronic and manual actuation, and the split of these functions into their respective actions couldn't be more perfect for swapping into the Taco. The VF2A uses the electronicactuator to shift from 2WD to 4WD on the first phase, and the second obviously switches down into the low range. The VF3AM uses the same actuator to shift from 2WD to AWD, and the second phase locks the center diff for true 4x4. Both the actuators operate here in the same manner, on the same shaft, and supply the same signals to the ECU. So with the VF3AM installed into the Tacoma, the transfer case control dial will be shifting to AWD instead 4WD. The 4WD center diff lock shift will happen on the second dial turn, this would be low range on the VF2A. Pretty simple. The H-N-L shift is on the manual shift stick.

The resulting available combos will make the truck much more useful and FUN. AWD low range for backing trailers up and around into precarious places, perfect! 2WD for mileage or fire road drifting? Easy. You get the idea.

There are several relatively significant mechanicals mods that need to happen... those include swapping the input shaft for the manual transmission, possible driveshaft length changes, and some other odd things.... the results will be more than worth it.

Comments? Criticisms? Have at it...

 

Super cool. That’s all I got at this stage.

 

Alright, several transfer cases at $200 a pop were easily turned up at nearby salvage yards. I'll grab one of those, along with a new input shaft for the manual Taco VF2CB, and then see if they still jell together. If they do, I'll order up a sparkly new VF3AM unit from Toyota. If only there was a nice 4:1 six planetary gear set available!

For those interested, this document from Toyota shows much of the various tech inside these transfer cases.

http://www.testroete.com/car/Toyota...l Training/02 - Chassis and Drivetrain/13.pdf

 

Moving forward.....

 

Nice, any idea how much cutting may be required to fit the shifter yet?

 

The t-case shifter will sit directly behind the the transmission shifter on the RC62F. That should make for a fairly simple rearward removal of the sheet metal in the tunnel. I suspect a double boot with surrounding plate from a 5 speed 95 - 04 generation truck or 4-Runner will work well here.

 

Well that is not going to bolt up.... first hurdle encountered. Looks as though maybe 2/3rds of the bolt pattern would line up, maybe none? Toyota likey changed the case right after this model. Hmmmm, more research to do!

 

Would the thickness of an adapter plate cause issues with input/output shaft length?

 

Well, first I need to see if any of the case aligns, or check for a case in the next generation that can can be modified to accept manual control over H N L. An adapter plate will likely cause shaft length issues, so it will be last on the list.

 

@RedBeard1 has a lot of knowledge about this stuff. Maybe he can toss up a nugget or two?

 

Thanks, maybe he will chime in.

I'm thinking the 05 - 07 Sequoia t case with a manual conversion on the H N L might be the ticket. The center diff is a Torsen in that one, too!

 

If you had started this project in November 2018 I would have hooked you up with my 05' Sequoia... I think the ECM went bad on it so we donated it and got the 18' Tacoma.

 

Maybe I misunderstood, but couldn't you just use the electronic HNL actuator and add some switches? That way you wouldn't have to add a stick and cut the tunnel to fit. Don't get me wrong, I'm all for levers and love my MT, but it wouldn't be too difficult to use the actuators as-is.

If you find an electronic one that will work and want some assistance with the electronics, sourcing connectors, and making up a harness let me know. I would be happy to help.

 

4th gen 4runner with the v6 is the one you’ll want. It’s a direct bolt up to a 2nd gen taco tranny. It’s got awd and center Torsen

Input shaft is the same, and you’ll have to adjust the drive shafts as the case moves the flanges back ~1” because of the center locker

 

Yes, the H N L actuator could be retained and wired up with it's own switches and controller... but I'd like to have at least one transfer case lever. Thank you for offering to help with the wiring, quite nice of you.

The 05 - 07 Seqouia looks to have nearly the same transfer case as the 4th gen V6 4-Runner.

Driveshaft changes are good... I can build em' with double cardan joints and reduce the various vibrations these late models units seem to have.

 

What about the awd case out of a fj. Granted you wound loose 2wd, but can get that back by the add on the front axle.

Or get the correct fj case, swap inputs and do the twin stick

 

No problem this is an interesting project. Obviously all the hard work is getting the right T-case and swapping parts. Details like stick or electronic are minor preferences.

Going to ask a dumb question now since this is in the 3rd Gen forum.... You are doing this to your '19 DC 6MT right?

 

I really want to keep the 2WD option... primary reason is 2WD w/ a locked rear diff = dirt road fun. Most of the time I prefer AWD.... especially when power begins to rise.

Yes, this is for my 2019 6MT.

 

Completely agree. This truck with AWD and a good torsion center differential would be stupid fun in the winter. I'm guessing due to vehicle and tire size differences the diff. would need some adjustment/tuning if that is even possible.