OEM+ Overlander

Soon... very soon. Just waiting on the connectors, and to sort out everything I’m putting through the firewall for A-TRAC. That will probably get done first, with a Bussmann RTMR.

 

To see if I'm on the same page...

1. Your truck is ALWAYS in AWD, either 4H or 4L. The rotary knob you jammed in the dash immediately to the right of the steering column ("cuz, well truck...") is from a T4R and simply controls whether the center differential is in HI or LO. Is that correct?
2. And the right-hand push button (of the two buttons to the left of the steering column) controls whether or not the center differential is locked. You demonstrate the functionality of this button in the first video of post #9 (dated Jan 28, 2019 at 11:21 AM). Is that correct?

 

Also, once you have incorporated A-TRAC, the benefit will be that the brakes will be automatically applied to any wheel that is slipping, but you will see more benefit than a "normal" Toyota, because the TrueTrac torsen differential will multiply the torque created by the brake and apply that to the non-slipping wheel. That is, A-TRAC will not mess with the center diff, will not lock it or shift in our out of 4H/4L, it just senses wheel spin, applies the brake, and the TrueTrac does the rest?

 

How do you like the TRD cat back?

 

That's correct

That's also correct

YES! This is exactly why I kinda need A-TRAC; because without it I could get one wheel off the ground and go nowhere.

It's fine, sounds mean because the doughnut gasket/flanges don't seal correctly, lol. I would probably recommend just getting the Magnaflow cat-back that nets more clearance underneath.

 

From previous research of how a Torsen / Truetrac operates, it is my understanding that "Truetrac drivers," without the benefit of automatic wheel braking (ala A-TRAC or similar system), learn to modulate the brake pedal, so if one wheel does spin, they can still move. I believe this is also how the military instructs HUMVEE drivers to use the brake overcome a wheel in the air, as the HUMVEE also uses front and rear Torsen differentials, with the center diff optionally locked.

So... could you not have done the same, and just learned to use your "spare" foot to modulate the brake pedal? (Although I can see how A-TRAC makes that so much easier.)

Lastly, if you lock your center diff, wouldn't you need to have one wheel in front AND one wheel in back to be "stuck" without either A-TRAC or manual brake modulation?

 

You're absolutely right about the manual brake modulation (and military Humvee training), but I'd rather just have A-TRAC do it for me

If the center diff is locked, you would need one wheel in front and one in rear off the ground to get stuck. So yeah, A-TRAC and brake modulation shouldn't be entirely necessary. My ABS is screwed and I'm a hipster, so I have to do something that no one else is doing and retrofit VSC/A-TRAC. This video made a compelling sell, for me:
https://www.instagram.com/p/BUzGLItgmtM/?utm_source=ig_share_sheet&igshid=11uxj2inin4s8

 

If I put together a kit for the AWD conversion (it would only work for 05-09 4x4 trucks w/o rear e-locker). Do you think people would buy it? How much would they pay?

Kit would include:
Transfer case to ADD connector Harness
Instructions on how to re-pin the connectors

Purchaser would have to:
Acquire x-case, diff-lock switch, 4x4 computer, and drive shafts.
Re-pin connectors

Ultimately, I think a decent shade-tree mechanic can do this conversion in a day, it's really not that complicated.

 

Make a kit for ATRAC retrofitting!

FYI, the early TRD OR don't have it either. I think only from 09 on

 

I actually might, but I'd need to invest in the right crimp-tool to make a quality adapter harness. I'm harvesting pins w/lead wires from the two-harnesses I bought to build mine. The real hang-up on A-TRAC/VSC is the damn brake pedals are different and I haven't swapped mine out yet to see if there's a workaround to use the non-VSC brake pedal.

Actually, they might, it doesn't seem to be well understood: https://www.tacomaworld.com/threads...dac-alsd-atrac-explained.184784/#post-4388605

The wiring diagram for an 07 FJ Cruiser shows pin 44 (HDCS) as ATRAC, but the Tacoma wiring diagram has DAC there. I'm really curious if DAC and A-TRAC are actually the same and just marketed differently.

 

My 07 OR 4x4 doesn't have the hydro boost, DAC or ATRAC or VSC

 

In the Instagram mikksup video you posted above (Post #28), is that a stock T4R with A-TRAC + stock 4x4 system? Were any Truetracs and/or any other LSD's or rear lockers involved? Or was that just stock 4x4 + center diff locked + A-TRAC engaged?

To recap... did the center diff you swappedin come from a T4R? (Or a TJ Cruiser or Landcruiser? I thought I read TJC somethingorother somewhere, and I'm a bit confused.)

 

I do however have the wiring in the dash for the VSC switch which I acquired (it lights up too with the dash lights) in order to use as ABS kill switch until I found out it's a momentary switch.

Now it just sits there and pretends

 

ha ha, yeah, both my A-TRAC/VSC Off switches are just dummies that light up, at the moment. I'm pretty sure all 4x4 trucks have the same dash wiring for rear e-locker, VSC Off, DAC. I can see the Rear Diff Lock/DAC/Slip/Auto-LSD lights on my TRD Sport's gauge cluster, and I'm hoping they all work

 

They do. Even on 4bangers. I installed an ARB locker on my cousins 2010 2.7L 4x4 and used a factory locker switch & switchback. 4bangers aren't pre-wired though but we found that giving ground to the yellow blue wire in the cluster connector turned on the rear locker indicator

 

That's an excellent question, but I honestly don't know if it's stock or not. Looks fairly stock, aside from the roof-top tent.

There are only two transfer cases. If it has 12-pins on the connector, that's what I'm using, it came on the more luxury model SUVs: V8/Pro/Trail T4Rs, Land Cruisers, and Lexus GXs. Anything with the 6-pin connector is what all Tacoma's came with. The only other difference is electronic vs manual switching (manual switching was only offered on FJ cruisers).

 

So if the yellow with blue stripe is rear locker what is the 4x4 and 4lo light wires?

 

Sorry I don't know. Not gonna tear the dash apart to find out now

 

Yea. I need to get back in there eventually.. currently lost some led’s shoved next to the switch. Although they go out and the rear locker lights up with I kill the abs lol

 

Here are my million dollar questions:

1. The transfer case with the electronic, locking torsen differential you bolted onto your transmission... would it mate up with the automatic transmission on 1st gen DC TRD OR with the V6? (Mine is a 2004 model.)
2. Did that same transfer case come in a manual version? (Do I recall some mention that it came in a manually activated t-case for the FJC or another Toy?)