A Trac broken?

Joined
Nov 7, 2006
Messages
48
Location
OR
Hi Guys - I was wheeling a couple of weekend ago in my fj and was climbing a really steep hill on a loose, rocky dirt road. I stopped the fj and placed it into 4 low after I couldn't get traction anymore out of 4. I went for about 100 yards, stopped again and engaged the A Trac. After engaging the A Trac (waited for the idiot light to illuminate), I started forward again and the fj made the most horrendous grinding sound and seemed to have trouble moving forward. I disengaged the A Trac and engaged the rear locker instead and everything worked fine (no grinding noise and forward monmentum). Has anyone had this happen to them or heard about it happening? Any ideas on what happened? Thanks in advance!
 
Joined
Apr 2, 2003
Messages
8,681
Location
Tucson, AZ
Hi Guys - I was wheeling a couple of weekend ago in my fj and was climbing a really steep hill on a loose, rocky dirt road. I stopped the fj and placed it into 4 low after I couldn't get traction anymore out of 4. I went for about 100 yards, stopped again and engaged the A Trac. After engaging the A Trac (waited for the idiot light to illuminate), I started forward again and the fj made the most horrendous grinding sound and seemed to have trouble moving forward. I disengaged the A Trac and engaged the rear locker instead and everything worked fine (no grinding noise and forward monmentum). Has anyone had this happen to them or heard about it happening? Any ideas on what happened? Thanks in advance!

TRAC makes the grinding sounds as it's your brakes modulating. Is that what you heard? Sometimes TRAC better than locker and visa-versa.
 
Joined
Mar 27, 2006
Messages
391
Location
Raleigh, NC
Just as he said.. that'd be A-TRAC doing it's work.. It really sounds like you just left the tranny and god knows what behind when A-TRAC is working.
 
Joined
Nov 7, 2006
Messages
48
Location
OR
That makes me feel a lot better! I really did think that I left most of the drive train on the trail. I had only used the A Trac once before, but on a much less severe incline so the brakes probably were not modulating near as much. Thanks!
 

woody

Staff member
Admin
Joined
Jan 15, 2002
Messages
10,359
Location
Toquerville UT
Website
www.TieRodMedia.com
ATrac works great with a steady engine rpm....basically, once it starts working, you hold that engine speed and let the system do it's job...those noises are part of it's process as it "feels" for traction.

for low speed stuff, the ATrac works awesome...when you need to "launch" into something, the rear diff lock is IMO a better choice, since it allows you to spin the tires and throttle thru.
 
Joined
Mar 27, 2006
Messages
391
Location
Raleigh, NC

lol... it "sounds" like you just left your tranny and god knows what behind..

The first time I used A-TRAC, nobody really knew how it worked specifically, atleast on the forums I visited and, lets not get into what the dealership knew as I think I knew more than they did when I bought it. I bought my FJ on March of 06 it's the #471th FJ out there for the public(excluding the first 1000 test/prototype models) so I naturally freaked the fxxx out when I first used A-TRAC and I literally thought I had screwed something up back then. After a couple months more knowledable people starting chiming in and I was releaved.

But yeah to add just a bit more info, the best mod IMO out there is the A-TRAC + RR diff lock for the early production FJs. As the rig will behave like it's "locked" front and rear but you'll be able to "steer" in the direction you want it unlike a "real" fully locked rig.

If the OP decides to do this or any other person decides to do it here's a step-by-step guide on how to do it.

http://www.fjcruiserforums.com/forums/4x4-off-road-tech/17329-no-cut-trac-rr-diff-hack.html
 
Joined
Jun 25, 2006
Messages
512
Location
Toostoned AZ
Atrac works for most situations, but when it starts hopping up and down it doesn't work so well. I recommend the atrac/difflock hack (alex mod) that allows you to run both simultaneously. As soon as you lose traction hit the diff lock button and right up the obstacle w/ no problems..works like a charm:) here is the link..hope this helps:)
(alex mod $10.00)
http://www.adventure4x4.net/waiting/showthread.php?t=270&highlight=atrac+hack

This is the no cut method

http://www.fjcruiserforums.com/foru...cut-trac-rr-diff-hack.html?highlight=alex+mod
 

MoJ

Moderator
Joined
Oct 24, 2003
Messages
4,398
lol... it "sounds" like you just left your tranny and god knows what behind..

The first time I used A-TRAC, nobody really knew how it worked specifically, atleast on the forums I visited and, lets not get into what the dealership knew as I think I knew more than they did when I bought it. I bought my FJ on March of 06 it's the #471th FJ out there for the public(excluding the first 1000 test/prototype models) so I naturally freaked the fxxx out when I first used A-TRAC and I literally thought I had screwed something up back then. After a couple months more knowledable people starting chiming in and I was releaved.

But yeah to add just a bit more info, the best mod IMO out there is the A-TRAC + RR diff lock for the early production FJs. As the rig will behave like it's "locked" front and rear but you'll be able to "steer" in the direction you want it unlike a "real" fully locked rig.

If the OP decides to do this or any other person decides to do it here's a step-by-step guide on how to do it.

http://www.fjcruiserforums.com/forums/4x4-off-road-tech/17329-no-cut-trac-rr-diff-hack.html


You should of visited the 100 series section here on 'mud. They've been using TRAC systems for years.
 

Users who are viewing this thread

Top Bottom