A-Trac? RR Lock?

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

Reply 1 : A-Trac? RR Lock?

Both systems try to control wheel slipping. A-TRAC applies braking (as in the wheel brakes) to the driving wheel to prevent wheel spin. Limited slip senses the slipping driving wheel and applies torque to the opposite driving wheel via a clutch system. Thought when the limited slip is engaged, the A-TRAC disengages.



You don’t have to always use A-TRAC when off road, in most cases just having 4WD is enough. Might do a little experimenting to see how each system works.

Reply 2 : A-Trac? RR Lock?

The rear differential locker is cool because it locks the rear wheels together so torque is evenly distributed 50/50. The problem with lockers is that they dramatically inhibit steering with the wheels always turning at the same speed. A-TRAC lets you have steering control and also helps with traction for the front wheels. Some guys over at fjcruiserforums.com have done a hack to enable the rear locker to be used with A-TRAC for ultimate traction (just one step behind having a front locker too). You’ll have to get into a pretty hairy situation to need either A-TRAC or the locker. I use my locker for fun but really haven’t needed it to avoid getting stuck….not yet that is. Like Toyomoho said experiment with them to get a good feeling for both and have some fun. (I would advise doing this off road in slippery conditions)

Reply 3 : A-Trac? RR Lock?

I bought an FJ recently. A-Trac AND the Locker can be engaged together when you are in 4LO without doing a mod. I bought truck used, but I seriously doubt the tool that owned it before me knew any of those options enough to do a mod.