how bout this swap so i can have 2wd?

any one use a v6 transfer case on a v8 truck?
reason for asking is i could potentially have 2wd mode for economy.
i have replaced the actuator o-rings on a v8 case and a v6 case & they look the same, save for the detent shaft & 4wd sleeve in the v6.

or better yet the fj case with a shifter?
any thoughts?

If you were local I've got a busted v6 transfer case sitting in the garage that you could try this with.

Contact Wyatt at RST and ask him. They do twin stick case swaps out of the FJ and it’s really involved. Requires a Tacoma front diff along with an FJ case and a good amount of interior trim work to fit the twin stick.


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A-Ha's Build.

I'm not so sure the V6 and V8 transfer cases aren't identical. I know the actuator is since there's one shifting beautifully in my V6 right now (labeled as a V8 model). I believe the only difference is that the dash switch has no 4HI setting (because that's default). The shift computer might be different but that could be something as similar as a jumper (never cracked one open). There's also no ADD on the V8 models.

I've never looked closely so I don't know if there's a space issue between the different types of front diffs. That's the only reason I can imagine they bothered with a full time 4wd in the V8. Anyone with a V8 care to chime in?

How much mileage do you think you're going to gain by getting rid of the Torsen, and adding an ADD front diff?

all good responses, couldnt find that on the search, not sure if itd get much better mpg but thats a hope any way. also missing the 4wd stick from my 91 and rwd burn outs are so fun, just love this truck so much more than all my other 4runners, i love the idea of the lefty inchworm case with gears instead of chains and 4.7 instead of 2.1, thanks again for directing me to aha's build thats just what i needed!!!

obsessed with 4runners since 2005

When I contacted Toyota, they said there are two models for the t-case actuator. Both models fit the v6, but only one fit the V8. Which means you can go from V8 to V6, but not necessarily the other way.

I want to correct this. Toyota was wrong. The V8 actuator, WILL NOT work on the v6. I am now looking for a V6 transfer case. 🤬

Want to bump this thread in case anyone can help. I went to replace my v8's leaky seals today and found that my planetary gear was grenading on me. Looks like the available salvage yards are asking 500 for the v6 model and 650 for the v8...
Wondering if i can swap over the actuator motor, rods, housings?

Just wondering...is it worth "saving" $150 to crack open the t-case and go through all the cleaning/sealing hassle?? Not to me. I jumped through hoops thinking I was smarter than Toyota engineers. I manged to replace my actuator from the outside (took new motor assembly and installed onto old t-case and shift rods). I wouldn't wish that on anyone. It was stupid, took twice as long as it should, etc. I got it all timed correctly and it shifts OK. But....cracking it open to install the brand new actuator assembly correctly would have been way smarter. And....that actuator is totally the weak link in the system. No way would I go through the hassle of putting a used actuator on a used T-case.

Just my $.02

I too have been day dreaming of this option. While changing my oil I was starring up at the oil pan and noticed how tight the space is between the extension tube and the oil pan. It’s just not physically possible to put the ADD in there. I think Toyota just chose to go with the full time 4wd option as an easy way out. In order to make this pipe dream a reality it’s going to take more than just parts. I haven’t done any real homework to speak of so don’t quote me here but rather help me walk through this thought process.

In order to get an ADD carrier in this tight space we’re going to need more room. The engine will need to go up a few inches (how much? TBD) with some creative fab work for the motor mounts and tranny mounts. The motor mounts are mounted at an angle to the block so it’s not as simple as adding shims. The mounting distance will need to be retained while they move upward. For the engine to go up we’re also going to need to install a body lift.

I hadn’t considered the concept of different actuators as a problem I just figured that Toyota would be too conservative to create a separate part for the v8. I also assume that the 4wd module will allow for the addition of the v6 switch to be simply swapped in for 2wd selection. Maybe the v6 actuator is more for the Torsen diff to send the power to the rear wheels?

I haven’t looked at the undercarriage wiring harness to see if there is a plug for the ADD or not yet but I’m not going to wait for the next oil change to investigate that either. I have a v6 switch with the 2wd option and I wonder how it will behave if I were to attempt to plug it in? I was going to pick up a v6 carrier as a doner not only for this possible option but I also plan on re-gearing to 4:56 and figured I could use the diff and swap the extension tube out. I may test this concept if I can locate the harness. With the switch installed and the ADD diff plugged in I could then determine if 1) the 4wd module will allow for this and 2) if the v8 t-case actuator will function and 3) if the ADD would engage. If I get a green light then I could go back to the original dilemma of making some room for the ADD. If it doesn’t go well then it will most likely be more involved than it’s worth.

Worst case scenario, there’s two guys here on T4R selling cvs kits with manual hub lockouts for around $2K as the last ditch option. Not that I want to spend that kind of money for this option but maybe it’s the easier route for someone else.

Cant wait to hear all of your thoughts on these crazy theories of mine.

I'm not sure that you would need ADD. The V6 transfer case doesn't spin the front driveshaft when you're in 2WD. You would likely need different length driveshafts front and rear.

Forgive my ignorance here, but all this effort really is to only stop the weight of the front drive shaft from turning. The front half-shafts and differential will always turn in Toyota's ADD configuration. All this cutting and hacking is to conserve a short stub of driveshaft from rotating. Would that even register as "fuel economy" compared to getting lighter tires?

Reasonably speaking, switching to full manual hubs would actually remove the entire front drive train from rotating, allowing the wheels to freely rotate.

Once we're cutting engine mounts and some-such, there'd better be a serious gain on the other side of the journey or the truck could end up a 5000lb paper weight.

Based on coast down tests I've run in different configurations with my '94, which has ADD and manual hubs, the biggest drag of the front drive train is the front drive shaft along with the ring and pinion. Part of that is because those parts are turning ~4 times faster than the CV components, making any friction 4x more significant.

Doing coast down tests, I couldn't really tell the difference between hubs unlocked (CV's stationary) and ADD unlocked with hubs locked (CV's turning). I could tell the difference when I engaged 4HI with hubs unlocked so that the drive shaft and ring/pinion were turning along with the CV's.