[cyberfed]

OK folks, I need some help here.
Seriously considering picking up an FJ. However all the different 4x4 features the FJ has has me confused as to what exactly does what and when you would want to use them..

here we go..

A-Trac system
Electronic Locking Rear Diff
4wLow
4wHigh
and any combinations therein

 

[SpeedRye]

See if this write-up helps -- http://www.fjcruiserforums.com/forums/transmissions-transfer-cases-traction-aids/6254-making-sense-trac-auto-lsd-atrac-vsc-rear-diff-lock.html

 

[snafu58]

That's the fun part, figuring it all out.
Basic 4X4, you are either in 2 wheel drive or four wheel drive.
4HI has the same ratio as two wheel drive, but you are in four wheel drive.
4LO is four wheel drive, but geared different for slower speed I.E. more grunt to get over obstacles that would create problems in 4HI and would probably stop you in two wheel drive.
ATRAC is a traction aid based on wheel spin.
Rear dif lock is a traction aid that locks the rear wheels.

 

[izzycc]

The above covered everything well, but here is just a slight expansion...

When you turn your vehicle, the wheels on the outside of the turn turn faster than the inside of the turn since they cover a further distance... Because of this, they need to be independent of each other:

Being in 2 wheel drive is actually just 1 rear wheel given power (one wheel spins freely, if the other has traction)

In 4 wheel drive, its actually 1 in the front and 1 in the back.

Rear locker "locks" the rear two wheels together so now when in 4 wheel drive you have 3 wheels that have power. (Can NOT be used on regular roads. You only engage the rear locker on slippery surfaces where you are basically stuck otherwise.)

A-track is the "technology" version of a rear locker but for the front. It uses the ABS to apply brakes to whatever tire is spinning and is not being productive, thus transfer power over to the wheel that is NOT spinning (aka, the wheel that actually has traction)

A-Track and Rear Diff Lock are pretty much only for very slow "i have no traction!" situations.

 

[lkn4drt]

The above covered everything well, but here is just a slight expansion...

When you turn your vehicle, the wheels on the outside of the turn turn faster than the inside of the turn since they cover a further distance... Because of this, they need to be independent of each other:

Being in 2 wheel drive is actually just 1 rear wheel given power (one wheel spins freely, if the other has traction)

In 4 wheel drive, its actually 1 in the front and 1 in the back.

Rear locker "locks" the rear two wheels together so now when in 4 wheel drive you have 3 wheels that have power. (Can NOT be used on regular roads. You only engage the rear locker on slippery surfaces where you are basically stuck otherwise.)

A-track is the "technology" version of a rear locker but for the front. It uses the ABS to apply brakes to whatever tire is spinning and is not being productive, thus transfer power over to the wheel that is NOT spinning (aka, the wheel that actually has traction)

A-Track and Rear Diff Lock are pretty much only for very slow "i have no traction!" situations.

very nice explanation. :cheers:

 

[fraglerock]

The above covered everything well, but here is just a slight expansion...

When you turn your vehicle, the wheels on the outside of the turn turn faster than the inside of the turn since they cover a further distance... Because of this, they need to be independent of each other:

Being in 2 wheel drive is actually just 1 rear wheel given power (one wheel spins freely, if the other has traction)

In 4 wheel drive, its actually 1 in the front and 1 in the back.

Rear locker "locks" the rear two wheels together so now when in 4 wheel drive you have 3 wheels that have power. (Can NOT be used on regular roads. You only engage the rear locker on slippery surfaces where you are basically stuck otherwise.)

A-track is the "technology" version of a rear locker but for the front. It uses the ABS to apply brakes to whatever tire is spinning and is not being productive, thus transfer power over to the wheel that is NOT spinning (aka, the wheel that actually has traction)

A-Track and Rear Diff Lock are pretty much only for very slow "i have no traction!" situations.

Fuq yeah! Thanks for that excellent explanation.

 

[GreenFJ]

Slightly different question. In the manual it says to use the 4 wheel drive at least 10 mi per month but they also advise not to use the 4 wheel drive on non-slippery surfaces. So if you don't find yourself on dirt/ice/sand/snow you shouldn't use it at all even if you need to do that 10 mi or should you use it anyway?

 

[Winterpeg]

Slightly different question. In the manual it says to use the 4 wheel drive at least 10 mi per month but they also advise not to use the 4 wheel drive on non-slippery surfaces. So if you don't find yourself on dirt/ice/sand/snow you shouldn't use it at all even if you need to do that 10 mi or should you use it anyway?

Throw it in 4 when you are on a long straight stretch of road.

The major issue is turning.... it creates driveline bind (as explained previously when the outside tires have to travel further than the inside tires during a turn).

In the first couple months of owning the FJ I drove on pavement in 4Hi.... straight stretches... I didn't wheel it much back then..... I don't have that issue anymore :rocker:

Play safe!
:cheers:

 

[GreenFJ]

Throw it in 4 when you are on a long straight stretch of road.

The major issue is turning.... it creates driveline bind (as explained previously when the outside tires have to travel further than the inside tires during a turn).

In the first couple months of owning the FJ I drove on pavement in 4Hi.... straight stretches... I didn't wheel it much back then..... I don't have that issue anymore :rocker:

Play safe!
:cheers:

That makes sense. I won't have that problem long either hopefully :bigthumb:

 

[Tonka Cruiser]

A-track is the "technology" version of a rear locker but for the front. It uses the ABS to apply brakes to whatever tire is spinning and is not being productive, thus transfer power over to the wheel that is NOT spinning (aka, the wheel that actually has traction).

i don't think A-Trac is front only i believe that it is both front and rear, but when you lock the rear diff it switches to front only. there is video on the web the clearly shows a rear wheel in the air and it is not turning. thoughts?

 

[Ragnar Danneskjöld]

i don't think A-Trac is front only i believe that it is both front and rear, but when you lock the rear diff it switches to front only. there is video on the web the clearly shows a rear wheel in the air and it is not turning. thoughts?

Yes, A-TRAC is front and rear.

Also, check this out - it is fantastic!

4WD Simplified Version 4.0 :bigthumb:

 

[opie's dad]

[quote

Also, check this out - it is fantastic!

4WD Simplified Version 4.0 :bigthumb:[/quote]

That is a very simple, understandable expaination of the Toyota Way

thanks for sharing...
Jax:wave: