Operating in 4 Lo Non A-trac Auto Trans.

Ok, I made the yellow wire mod today. Two questions please. When operating in 4 Lo in muddy areas with an automatic trans. do most of you leave it in regular drive or do you shift down to lower gears and leave it there for slow traveling on diverse terrain? Not trying to gain speed, but want to have the right combination of speed and torque if needed. Second question. When pulling some one out that is stuck, after putting in 4 Lo would you put it in first and leave it there until they are free or have it in second gear? Now that the yellow wire mod has been made and traction control is working in 4 Lo, wanted to see if it makes a difference as to what gear when pulling some one out using auto trans. Thanks for your help

 

The gearing is unchanged with TRAC ON, you just have ALSD (Auto Limited Slip, non-regulated engine output) traction in L4 now instead of Open Differentials.

I would use momentum to keep moving through mud, but if really wet, you want to avoid getting too much water thrown up in the engine compartment! Try it in Drive before down shifting, because in Low Range, you overall gearing is much lower anyway. See what others say, as I have not pulled anyone out of mud...

 

Higher (wheel) rpm will create a stronger limited slip effect. As well, the algorithms for TRAC use a progressive application of the brakes, (ALSD effect) based on the wheel rpm, and difference of wheel rpm. I found that 1st gear did not turn the wheels fast enough, unless it was revved to the 4000 rpm range, which is unnecessary. Second gear was a good combination of torque and wheel rpm. Basically, you will find it most effective is 2nd, or 3rd. Most of my testing of the TRAC mod, was 2 wheels in the air, fully crossed up, going uphill on sand or mud, at very slow speed. So I was testing the extreme end of what TRAC is capable of. In the mud, wheelspin is as important as anything, so 3rd or 4th might be best. In addition to that, due to the limited pressures generated by the pump on the non-hydraulically assisted models, higher wheel rpm generates more brake pad friction, which transfers a greater amount of torque. Remember, this is a brake based system, and wet pads are not as effective.
Previously I thought rpm affected the TRAC system, but I now believe only wheel rpm does, not engine rpm.

 

Thanks guys that is exactly what I need to know. And while I'm at it, on behalf of us non TRD O/R guys, thank you for the yellow wire mod.

 

A lesson for any serious off roader... GET THE OFF ROAD TRD 4WD TACOMA!!! The hydraulic brake booster/ Active Traction Control is dynomite.

 

Basically I went bare bones with my 4X4 AC cab and do not regret it. I previously had a 08 Pre-Runner until some one rear ended it. I like the 09/10 upgrades and with the lower monthly payment and yellow wire mod, she has and will do everything I need. This one will be a keeper for a while. Thanks again for the info!

 

Have fun with it, dbarn!