FJ case in a 3rd gen tacoma

Not sure how well this will work but here's the AutoDesk Fusion 360 file for the template I made.

https://drive.google.com/file/d/1UG5l5f6IKYaqSfCc4CaG5ifd5xIHL9CQ/view?usp=sharing

I ran the dowels long so that you could cut them to length. Not everyone is going to grind their shift rods the same, so make sure you measure and cut the dowels as needed.

 

Figure out an elegant solution on existing electricals?

 

Sure did!!

 

Ahhhhh
Option 1, hard to beat it.
NICE

 

Haha yep, it's "temporary" ... I took the actuator apart to clean it and see what makes it tick, and in doing so I screwed up the timing of the gears/limit switches. It doesn't "shift into 4wd" anymore, but at least the dash isn't lit up all the time.

 

Hoping I dont have to grind for my install to my r156f

 

I’ll have to take a look at the 3rd gen schematics, it should be easy enough to over ride with a manual switch or existing transfer case logic.

 

Thanks, I'd really appreciate another set of eyes looking at it. Especially yours lol!

 

It doesn't look like the ADD controls have changed much between the 2nd and 3rd gens other than the CAN bus communications. I am not sure how to defeat that signal from causing a trouble light on the dash, some more research is needed here. Since your ADD actuator is stuck in "4wd" mode, you can divorce the feedback from the ADD actuator by using a toggle switch to simulate 4wd or 2wd condition of the actuator sleeve. Make sure you unplug the ADD plug under the truck to kill any erroneious feedback from your ADD actuator.

 

Based on my experience developing 2lo mod on the 3rd gen, you cant just spoof the ADD signal from the front diff actuator on a 3rd gen (unless you like throwing codes).

Based on what I found, the 3rd gen seems to check every one of the feedback lines (during mode changes and startup). So you need to spoof them all. A single error in any of them, or not seeing proper resistance of the motor, or any motor current leakage to ground results in work stoppage.

For the transfer actuator, the ECU even looks for the progression of signals, and cant be spoofed straight from 2hi to other modes. (The ADD can on the other hand just be simple spoofed to give electrical 2lo).

The below thread is the best I have been able to figure out, to allow for removal and spoof of both actuators, and provide ECU spoof of 2hi and 4lo as desired. (Without a microcontroller, which is beyond my skills to make reliable)

Drawbacks - 1 ecu spoof activation requires power cycling the truck to operate the spoof, because the ECU is looking for that signal progression.

Drawback 2 dash lights are not easily controlled in any meaningful way (the dash signals are CAN controlled).

This is literally everything of use that I have learned for 3rd gen (to spoof both actuators)...
https://www.tacomaworld.com/threads/4wd-ecu-spoofer-for-fj-transfer-case-install.693450/

 

wow, just when I think Toyota would not get any dumber with their designs they go ahead and do that. Hmm, well I would still go ahead and if you have an fj case installed, to leave the ADD collar locked in and be done with it. My trucks been that way for thousands of miles with no downsides. If you need the traction control in different modes it would required some figuring out of what reach terminal reads feeding into the ECU as a shift is performed. This can easily be done using an oscope. Unfortunately I don’t have any 3rd gens around here or I’d love to take a dive in. You could simulate the whole operation with a one shot using a small microprocessor.

 

Damn. I need you in my life
I have an intermediate axle shaft from the manual FJ so I'll be swapping that in pretty quick.

I was talking to one of my buddies who drives a lot of 1st/2nd/3rd gen dodges and he was saying some of the dodge trucks have a similar system, and they've made kits to shift that collar manually. Might be a cool option for someone that wants to retain the "factory design".

 

I had this on my old Dodge and absolutely loved it. It was from 4x4Posilock if I remember correctly. Cable actuated. 2LO was a breeze. I suspect these computers would have a shit fit if that system was installed on these trucks.

 

Super interesting, and kinda tempting.

It definitely would freak out, but in my case, the ADD actuator can keep my tcase actuator company in the passenger seat until I figure out a way to spoof them both!

 

https://4x4posi-lok.com/

They dont list any for Toyotas. But its just a fork that slides over the actuator. You might could find one the right size and figure out a way to make it work.

 

I messaged them years ago and they didn't have any interest in designing one for Toyotas

If you know someone in the south jersey area that wants to be a guinea pig I'd be more than happy to hack up a newer taco

There is also a company that makes manual e-locker cables (though this is for the 2nd gen, since 3rd gen is a solenoid and not an actuator motor like previous), I have to wonder if they'd be interested in designing manual shifting for ADD.

https://www.chilkatdesigns.com/

 

I don't know of anyone out that way, so hopefully someone pipes in.

That's not a bad idea, although I do like the design of the posilok system better. But unless I find a huge downside to the FJ intermediate shaft, I won't be trying to make this system work.

 

I think you won’t. Maybe a slight wear on the chain over time, but nothing significantly noticeable that couldn’t be fixed during a normal overhaul. Just have to remember to grease the front driveshaft a little more. It was never a big deal for me because i shot all the zerks at the same time when I grease everything. The thought of the 4wd working every time you need it and not relying on 20 switches and a computer to process them is worth that peace of mind

 

That's my thinking as well, even if I have to replace u-joints once a year, it's still totally worth it. I'm sure wheeling is 10x harder on your drivetrain than any kind of wear this would ever put on it. I was told I would loose some fuel economy but I've never cared about that.

 

What was the final parts list for this? I have a manual TRD Sport I'm looking to do the swap but what else is needed besides the automatic transmission FJ transfer case?

Also, was the ADD figured out so it's always locked in? What's the point in a manual transfer case if the front differential still has an electrical component