2LO Mod

Has anyone heard of this mod?

I've only been wheeling a few times, and I'm starting to build up my truck so that I can explore more remote areas. But with a manual transmission I can see the benefit of having 2LO so that I don't burn up my clutch. A good example would be wanting the control to go slower around steep switchbacks, where turning in 4wd would cause binding.

I'm open to suggestions about how to best handle that situation BTW (don't forget I'm a manual). But for the most part, I'd like to stick to seeing if anyone has pulled this mod off.

As far as I understand, there *may* be a way to trick the ECU into thinking the truck is still in 2WD after shifting it into 4WD which would disengage the ADD (Automatic Differential Disconnect??)......or something like that. I'm not totally confident I know where the ADD is, or what it does yet.

The information I've found so far were people speculating that it can be done, and some talk of people that have done it by simply installing a switch. But so far I've come up empty on finding a how-to thread or even partly detailed information. Anyone done it? Or have links?

 

This is something I want to do as well but haven't gotten around to it yet.

Here's the thread that I found with a mod that seems to work.
http://www.tacomaworld.com/forum/2nd-gen-tacomas/195424-2wd-lo-mod.html

 

Wow, good find. I'll have to read that over tonight.

You planning on doing it soon, or whenever you get to it?

 

I did it a few years ago, but don't really remember the specifics. I think I just used a switch to force an open in the wires to the ADD.

 

Probably will be a while until I get a chance to play with doing something like this, although I think it'd be a great mod.

 

If you find yourself Wheeling to a spot that necessitates 4wd the ground is obviously slick enough to not cause damage by turning in 4wd... That stated there is the 2lo mod and it doesn't seem that hard.

 

Many people, myself included want to use 2lo when backing up or towing slowly in tight spaces.

 

perfect situation for 2lo

my reference was to the OP's situation.

 

^ What method did you use?

 

awesome answer. I've considered the Taco box for more versatility, but if anything id get rid of 4hi instead of adding a 2lo, but that's just me

 

X2



You probably could just do the rocker switch for the ADD with the electronic transfer case to get 2lo but the tcase would still be engaged, just no power to the front wheels.

 

So I've been trying to do a little research on exactly how the 4WD system works, so that I don't damage anything when trying this mod. Plus, I like to completely understand things before I go messing with them. It's probably pretty standard knowledge but I had to search for it. Here's what I've found how the system works with a stock 4wd system - 2nd gen.

In 2HI, the T case only sends power to the rear drive shaft.
In 4HI, the ADD **engages first**, then the T case shifts to send power to the forward drive shaft in addition to the rear drive shaft
In 4LO, the ADD stays engaged (since you go turn the knob through 4HI first), and the T case shifts into LO gear, still applying power forward and rear.

Does the ADD need constant power to stay engaged? I saw a post in a FJ T case swap thread that said to use a momentary switch, but it was unclear if it was in the same context as this.

Also in my research, I've found that the ADD is often a point of failure. I wonder if there's a way to make it a cable actuator instead? I saw some mention of it on older 4runners, and maybe 1st gen Tacomas with the vacuum ADD.

 

I like your thinking of a cable mod for the front add, I have done the Fj TC swap and it is amazing with my 6 spd manual and then again my front add went out so now I am looking for another ADD for cheap and one for a spare !!!

 

I found this over on expedition portal. You might check it out because the fix was to remove the unit and resolder the connections to the motor, and maybe the limit switch since it's all apart. Worth trying anyway, to save $300.
http://www.expeditionportal.com/forum/threads/90151-Late-Model-Tacoma-4WD-Actuators-Failing/page3

This was in the same thread - a link to an OEM replacement part that eliminates the ADD. It's from a Full Time (AWD) vehicle. From what I understand, swapping this part in makes the front diff act like a normal front diff, so the wheels will backdrive the front driveshaft I think, which may not be normal, and may wear out a seal or something - not really sure though. Just being cautious since it's probably not meant to be backdriven 24/7.

In the way of being cautious, it'd be cool if that cable actuator existed.
http://www.justdifferentials.com/product-p/toy41400-35032man.htm