Off Road

Let me get this straight for the gen 5. Locking rear diff only works in 4low, not 4hi? Atrac will only work in 4low, not 4hi? BUT you can use the mud/sand setting of MTS in 4hi, and that's sort of a de-rated Atrac setting? Does not seem to be many options for running in snow over 10mph.

 

Locking rear is not meant to drive fast as you can break things if you turn going fast in grippy terrain. A-trac is a brake-based system to mimic locking diffs at slow speeds. MTS mainly controls ABS and throttle response settings depending on terrain.

You should not need anything more than 4hi and possibly using MTS mud setting in snow as long as you have good tires.

 

Hey OP
Great questions
Correct, can only lock in 4LO
The dash light will illuminate solid when truly engaged. Flashing light not engaged.
Couple expert users who are smart cookies on this topic:
@whippersnapper02
@Captain Spalding
@McSpazatron

 

You can always do the locker mod:

chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/https://www.4runners.com/attachments/toyota-4runner-rear-diff-lock-wiring-pdf.129169/



***EDIT*** This is only for the Trail Edition.

 

Ooo, please explain!

 

This is a copy & paste from the link I posted:


It's really straightforward. There's a 4WD ECU behind the glovebox with an input from a switch on the transfer case that tells the ECU when you're in 4L. That input is the LIGHT GAUGE blue wire on the LARGER of the two plugs into the 4wd ECU, not to be confused with a heavier gauge blue wire on the second, smaller plug.

When you're in 4L, the transfer case switch grounds that wire to let the ECU know that you're in 4L, thus enabling ATRAC & the rear locker. So my solution was to rig a manual switch to ground that blue wire to fool the ECU into thinking you're in 4L, and then the locker & ATRAC will work in 4H. And it works.

You've got to pull the glovebox, but once you do the ECU is right there. I spliced into the blue wire, ran that wire to a switch, and the other terminal of the switch to ground. When I'm in 4H & flip the switch, the 4L light comes on and ATRAC & the real locker are enabled. Nothing to it.

Again, this mod only applies to the Trail Edition models - those with ATRAC & the locking rear diff. It's worked for me, but obviously, experiment at your own risk...


Diagram of what's where - 4WD ECU is #2, 4L switch is #4




Wiring diagram




Parts that have to come out to get to the 4WD ECU




Where the 4WD ECU is located with the glovebox out:

 

What scenario would you use/need the locker in 4H?

 

I did the locker mod on my Tacoma. It was nice to be able to disable ABS and get more traction in 4wd high when desert running.

 

When I engage my locker usually have to completely stop and turn wheel slowly to get it engage.

I assume same would be required if engaging in 4h or am I missing something.

 

It's locked out from 4wd high from the factory. It will just flash the light.

 

Correct I am referring to if a mod can be done. On my taco it was called the grey wire mod but didn't think we can do it on 4r.

Even with mod being able to use it I assume have to almost stop to get it to engage.

 

It would be the same, push the button while going forward at 5ish mph and turn the steering wheel to engage. Once it's in you're off to do whatever and you even disable ABS which helps you stop in dirt.

 

Awesome mod, and probably would be good in deep snow. BUT, I would think disabling ABS in snow would be undesirable.

 

No ABS on loose material builds up a mound in front of the tire which sort of helps slow you down.

 

If you're in snow deep enough to need the locker, go into 4low and keep the revs up to maintain speed. Easier on the transmission that way.

A-Trac allows no wheelspin so it's useless in snow (and sand). MTS in mud/sand setting is more appropriate.