I just purchased a FJ Cruiser 4WD 07 and it has the A-Trac and Rear Diferential Lock functions. I have read the manual and I understood the meaning of those two terms but have few questions?
When do I have to use the A-Trac? Every time when I go Off Roading? And What is the difference between A- Trac and Rear Diferential lock? I will appreciate your help.

Regards

 

i don't know what the a-trac is, but the rear locker, "locks the rear diff, forcing both tires to move at the same speed, with the rear open, you get peg legging, where the tire with the least amount of traction is the one that spins. when you lock the rear and go to make a turn the tires will skip or chirp, with it unlocked(daily driving) it will be open allowing both tires to turn at different speeds when turning. hope this helps


corey will know about the a-trac

 

I think the A-Trac actuates your brakes to keep wheels from slipping. How the A-Trac and the locker work in tandem I cannot say.

 

The A-Trac and Locker do not work in tandum without a hack, so far. But locker is as stated above. A-Trac will do like stated above. It locks the free wheeling tire using the braking system. That in turn makes the power go to the wheels that do have traction. Basically with this on, if you can get one tire to touch the ground, you have a great chance of not being stuck. I have used it and am more impressed then I figured I would be. No off-roading vehicle should be without A-Trac. It makes climbing anything just down right easy.

BTW - if you search "a-trac" you would get the thread that explains this in far detail and I think it even has a link to the video explaining a-trac in action.

 

A-TRAC is a function of the brakes, it sences wheel spin and will brake the wheel that is spinning. It is a really neat tool, I love it in my taco. I can one front and one rear wheel in the air going thru a ditch and the a-trac keeps your driving along. Not sure if you can use it in 4H on the FJ or not, but on my taco in 4H it limits throttle and brakes wheels, in 4L it only brakes the wheels.... I am also curious press the A-TRAC button in 2wd, do you get a Auto-LSD light like I do?

Also on all TRD SE FJ's and FJ's made after last Nov you can use the locker and A-TRAC at the same time, so your rear is mechanically locked, and the front has a Auto-LSD, really really cool.. I cant do this on my taco and would love to be able to do so....

On my taco A-TRAC defaults on, so its always on in 4WD, but I can turn it off if I want to. My locker also disengauges it. Personally I leave it on unless it creates an issue, then I kill it. So far it has been very helpful, and even better than the locker when I have been playing... The locker tried to slip me sideways on a steep hill crossing a ditch, where the A-TRAC kept me going straight.... thou there are times when the locker will out preform A-TRAC.

 

i got a 07 FJ cruiser that i bought late october of 07. some people are writting that you cant have the rear diff lock and the A-TRAC on at the same time. true? when the diff lock icon blicks it means on, right? My Fj can have the A-TRAC and rear Diff lock at the same time on L4

 

A flashing RR DIFF LOCK light means that it is not engaged, for some reason (wrong speed, wrong xcase range, etc...) it wont engage. There are some FJ's that allow the use of both, whether it is by a wire hack or from the factory depends on the FJ.

 

Later production 2007 FJs do allow both the E locker and A Trac to work at the same time in 4Low.

Mine does not, mine was made June of '06.
Most rigs built October of '06 and beyond have both working together when engaged.

 

Doesn't that suck when they upgrade or add something cool right after you bought your's? Is it really a big deal to have tandem use of both off-road? I guess it doesn't hurt.

 

can you use the A Trac and rear diff lock in 4 high and 4 low on the TRD version FJ?

 

4WD Low only... Usually if I'm driving a trail that has me in 4WD Low I leave the A-Trac on and only engage the e-locker when necessary.

Here is a link that has the 2007 owners manual. Starting on page 120 (134 of the pdf) they explain the 4WD system and the various options.

 

are there any wiring tricks that allow the rear locker and/or a trac to work in 4 hi?

 

Yes there is.
It is called the gray wire mod I believe.
If you Google it, it should pop up.
There may be info in this same section posted by me finding out how to do it also.

 

so does anyone know..

will the grey wire mod allow the atrac to be used with the rear diff lock?

and....it will allow the diff lock to be used alone in 2 hi, 4 hi, 4 lo

please advise

thanks!