Gasp - ATRAC not doing so well?

[Crispin]

So after Lincomb and me being kind enough to let Rob use his new strop, I am wondering if my old friend ATRAC is working very well?

Rob pointed out that my rear wheel was in full contact with the ground (suspension compressed) but it was making no attempt to move. The opposite wheel as well as the fronts were spinning.
I thought I had felt the same in some mud earlier - front left was in the mud but I had very little drive.

Later on the axle twister, you can clearly see it doing....nothing.


Gary went over before me without any faf. At first I put it down to his tyres having a bit more grip than my ATs

 

[Gary Stockton]

Did you lock the centre diff? Dunno if that makes a difference though?

 

[Crispin]

ya, it was locked (It's always locked in the forest)

 

[Gary Stockton]

Mm - ok. It's bust then?? Can't see how really? Lots of sensors involved ...

 

[Jon Wildsmith]

I seem to recall reading before that having a single wheel with traction confuses it.

 

[Trevor]

You still made it which is the key thing, rear locker for your next mod?

 

[Steve]

Is the traction control not disabled with the centre diff locked?

 

[Graham]

You still made it which is the key thing, rear locker for your next mod?

.
I guess he will be looking for an LC3 rear axle.

Graham

 

[Crispin]

Is the traction control not disabled with the centre diff locked?

Traction control (VSC) is disabled but that is separate to ATRAC which only starts working when the CD is locked.

It seems a bit weird how it was working, you can clearly see it breaking the spinning wheel but that had no effect on the wheel which still had traction.

I seem to recall reading before that having a single wheel with traction confuses it.

A locker from an LC3 does not fit onto a LC4/5 as Gary has found out.

 

[Gary Stockton]

You could do a full rear axle case swap as you've got springs at the rear. I couldn't go that way due to the air suspension mounts ... The diff housing itself are different though so hassles there and with the wiring loom. ARB air locker would be the best option

 

[Andrew Prince]

Lucky you've added the winch - maybe a ground anchor would be cheaper than an air locker

 

[fast but dim]

we've probably all seen this but it's a good thrad on using atrac:

http://www.toyota120.com/forum/showthread.php?t=25

 

[Graham]

Is the traction control not disabled with the centre diff locked?

Traction control (VSC) is disabled but that is separate to ATRAC which only starts working when the CD is locked.

It seems a bit weird how it was working, you can clearly see it breaking the spinning wheel but that had no effect on the wheel which still had traction.

[quote="Jon Wildsmith":29d6vfzl]I seem to recall reading before that having a single wheel with traction confuses it.

A locker from an LC3 does not fit onto a LC4/5 as Gary has found out. [/quote:29d6vfzl]
,
not just the locking diff, but the whole gubbins.

Graham

 

[Crispin]

it's all a bit of a hassle. I'll just go faster next time

 

[Rob]

Crispin, are you sure the centre difflock is actually engaging when you press the button? If the the centre diff is locked then looking at a single axle where one wheel is spinning and the other stationary, when atrac brakes one wheel the other should start turning. If not drive is going to the other axle meaning the centre diff lock is not functioning.

 

[Crispin]

Crispin, are you sure the centre difflock is actually engaging when you press the button? If the the centre diff is locked then looking at a single axle where one wheel is spinning and the other stationary, when atrac brakes one wheel the other should start turning. If not drive is going to the other axle meaning the centre diff lock is not functioning.

The light flashes and most of the time goes solid quickly (locked) sometimes a nudge forward is needed to make it lock. It would have been on and locked (as per the light) with that.
The one thing I was thinking is that if it were dumb, it would not brake the two spinning wheels at the same time. Braking them at different times (sequentially) would just send the power to the other spinning wheel. Any time you are on an axle twister, it would have to brake the opposite corners at the same time in order to free itself with a locked CD.

That is all I can think because as you can see it is either a) and open CD b) not braking the wheels at the same time as there is no attempt by the "good wheels" to turn.

There is a grassy "hill" near me which is a good test of a CD being locked, when unlocked, fronts slip and I go nowhere, CD locked and the rears, still on tar, push me up.
I'll pay it a visit tomorrow.

 

[Crispin]

we've probably all seen this but it's a good thrad on using atrac:

http://www.toyota120.com/forum/showthread.php?t=25

I've watched those vids before and actually forgot (at that time) about the "keep it steady around 2000" stuff. Earlier on in the day, that lovely step / hill up towards where the tennis balls were (it was the exit for the tennis balls) it worked perfectly there, initial slip but keeping the pedal constant and engine around 2000-2500 it just starts picking its way up.
Pretty sure it does work as it is supposed to (don't think I would have made it many places if not), would just like to understand it a bit better.

Roll on May...

 

[AndrewT]

When your Atrac works you should also hear the clicking, a little similar to the descent control.

if it is working, it is pretty effective, but you should get it checked out as I am pretty sure it uses the ABS sensors.

Cheers

 

[Crispin]

the noise is there as well as the rock-hard brake pedal so I've no doubt the system is ok, it just seemed to do a bit of a poor job there getting me out.
There are other times where I've been stunned at what it has managed to do. (no one mention the grass incident! )

 

[adrianr]

no one mention the grass incident!

well, that did leave you stunned too I bet!!