a-trac 101 (3 Viewers)
- Thread starter 2000UZJ
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Like most things about A-Trac, think the answer for off-camber is it depends.
The axles that are locked on steeper off-camber will "walk" to the downhill side. Not a problem if have room to spare, but if you are off-camber above a drop off, a-trac might be a safer option.
Nice write-up. Atrac is a great tool and I like having the capability. There are certain conditions where power braking over obstacles is required. Slow and more than the delay on ATRAC is required. Power Braking is when you put your foot on the brake and rev the engine to 1000-1200 RPM, releasing the brake to provide forward momentum and pressing down to stop or slow your progress
Pressing the brake disengages A-Trac. One of the reasons I got lockers, besides the weak front diff.
There are a lot of trails this wouldnt be needed. The Rubicon , Holy Cross (Colorado) and some other Colorado trails are appropriate for Power Braking
Pressing the brake disengages A-Trac. One of the reasons I got lockers, besides the weak front diff.
There are a lot of trails this wouldnt be needed. The Rubicon , Holy Cross (Colorado) and some other Colorado trails are appropriate for Power Braking
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I love revving my hundy to 12,000 rpm and then dropping the hammer 
BamaHeel
Intergalactic Champion
No first hand experience; however, I did find this:
the third can fit in any 9.5" housing. you would have to modify your housing for the elocker to fit
Below is a photo of a front housing, showing the new holes that need to be drilled and the area that needs to be notched. As can be seen from the photo, it can be done
Came from this thread:
https://forum.ih8mud.com/sale-parts/497868-100-series-9-5-electric-locker-third-memeber.html
If your axle was locked and you had ATRAC, wouldn't the ATRAC be applying the brake to the spinning, off-the-ground wheel and therefore be attempting to stop the whole (locked) axle? It seems like if you were locked at one end you'd want ATRAC disabled at that end.
Been covered in a number of threads. When axle locked A-trac would not see a difference between left and right wheel speed, so no need for it to brake a wheel.
To oversimplify 2000UZJ's fine write up, a-trac applies brake to the wheel or two going faster than the rest to make it go same speed as the others, with lockers they are going the same speed.
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Thanks for the great write up allot of usefully info.
Nick - Thanks for the tips. They really helped out with my wheeling this past weekend. The rev range was really helpful. Also, I used the 2nd gear start button quite a bit when covering ground between obstacles while in low range.
A-TRAC video. I aired down to 18 psi.
Uwharrie - Dickie Bell - YouTube
A-TRAC video. I aired down to 18 psi.
Uwharrie - Dickie Bell - YouTube
Hey, just a quick question... I'm thinking of potentially moving into a sequoia (family size) in a year or two. I'm just wondering if it has atrac, and also if it does, then does it work very similarly? Are there differences? Anyone here know, and perhaps those that have driven one offroad could chime in?
My goal wouldn't be to purchase more capable vehicle (obviously); and that being said, I don't really wheel mine too much, and when I do, it's extremely light, mostly FSR's and the odd spur off to the side that's a bit steeper, but that's it.
My goal wouldn't be to purchase more capable vehicle (obviously); and that being said, I don't really wheel mine too much, and when I do, it's extremely light, mostly FSR's and the odd spur off to the side that's a bit steeper, but that's it.
Same system...differnet flash software. It's very intrusive on the Sequoia and it's really easy to get stuck in sand, mud, etc. Main focus is vehicle control due to size and the way folks use the vehicle. It is NOT biased for off-roading like it is on the 100.
I didn't see any comments about potentially upgrading the software to a newer version of A-trac.. I wonder if that is possible?
It is really cool technology.
I have been told the best aftermarket lockers are superior to the OEM e-lockers, so probably better to buy after market then try to install OEM e-lockers.
It is really cool technology.
I have been told the best aftermarket lockers are superior to the OEM e-lockers, so probably better to buy after market then try to install OEM e-lockers.
They do not change the software unless it's via a recall, TSB , etc. They did this on the GX460 as it did not intervene early enough and they could spin out/slide. The upgrade now prevents that.
And yes, ARB lockers are stronger, lock faster and unlock faster than OEM. They are my choice for sure. Plus you can lock them without having to lock your CDL (an advantage in certain situations).
The biggest help for me was the constant throttle between 1200 and 2000 and let it work. Once over that hump of letting off the gas, the A-TRAC went to town and did it's work.
I was recently playing around on some "moguls" and I wasn't very impressed with the ATRAC on my '02. I was in 4L, in Drive, CDL locked, and held a steady 1500 rpm or so. One of the rear tires was spinning freely for a good 5-seconds with no traction so I let up on the gas. Should I have stayed into it longer? I ended up backing up a bit to carry a bit more momentum and then I was able to roll right through the little "obstacle".
On my previous '07 FJ Cruiser, the ATRAC system was flawless. The ATRAC worked so well I never needed to lock the rear differential.
I understand that the newer ATRAC system uses dual sensors at each wheel for a more aggressive ATRAC intervention, but is there an updated software for the older LC's to improve ATRAC functions?
Maybe there's something wrong with my ATRAC.
Any help would be greatly appreciated.
On my previous '07 FJ Cruiser, the ATRAC system was flawless. The ATRAC worked so well I never needed to lock the rear differential.
I understand that the newer ATRAC system uses dual sensors at each wheel for a more aggressive ATRAC intervention, but is there an updated software for the older LC's to improve ATRAC functions?
Maybe there's something wrong with my ATRAC.
Any help would be greatly appreciated.
Yeah, I remember there was someone from this board a year or two ago that had similar issues with his ATRAC, I think his name was Sonk76 or something like that. Anyway, not sure you're around Sonk, but how did that all turn out?
Yup. That was me. Never got that situation working. Chalked it up to the system having reached its limits. My theory remains that with better brakes the system would have more capability.
I fixed this by installing lockers and haven't worried about it since.
I fixed this by installing lockers and haven't worried about it since.
