Thread: True Trac or Detroit Locker

I just bought an Ashcroft ATB from LRA ( and another one coming over for the front) for my Defender ( adding some Maxidrive axles and flange for the rear since I have gone through one set already under warranty)

I have Trutracks both front and rear on my Discovery, and they are great - really transformed the off road ability.

The traction control on the Defender works well, but I found going up a few steep creek exits last year on the OTT was more difficult than I found doing worse and slipperier slopes than in the Discovery.

This years trip has the potential to be in some loose and slippery conditions, so the Ashcrofts are an insurance policy, and at $777 including shipping and the adaptor plate for the diff, I think it's good value. You may get them cheaper direct from Ashcroft, but they were out of stock.

I am a great fan of the detroit.
You must up grade rear drive flanges and axles.
I have been running the detroit in the back of my 101 for many years now and also have a ARB in the front.
The 101 Landies wheel base is 101 inches verses 127 inches of the defender both running a salisbury.
The 101 has no power steering with that shorter wheel base and the 101 will tow/carry a heavier load off road.
I run 36 inch simex.
Both vehicles are constant 4WD.

What I am getting to is if a vehicle is going to feel any bad effects between the two vehicles with a detroit in the back it will be the 101.
To date the detroit has been barely noticeable except for extra traction.
The detroit doesnt dig holes in the sand or cause the vehicle to slip side ways on a slope........why would it as it is locked just the same as a manual locker when off road.
Any effects of digging in or going side ways is way beyond the point of where you would go with open diffs and is the same effect of a vehicle at its limits with a ARB/TJM locker ect.
I regularly tow heavy loads though round abouts and up camberwarra MT hair pins on the stubbie 101 with not problems or ill effects.
Constant 4WD system is the key on road as the drive of the front diff hides any presence of the detroit in the rear.
Most people who knock the detroit have had early versions and in part time 4WD systems......ie series 3 landy not so good.
Defender with saisbury......perfect.
The detroit is a easy fit in the salisbury.
Ron
Ps
Yes there is some extra back lash put in the system, but not a great deal and not worth worrying about.
No difference to tyre wear or anything like that, but rear tyre pressures will need to be kept equal as they should be any how or the vehicle may want to pull to one side in the steering on a tarred road.......good tyre pressures and no issuses.

Originally Posted by djam1

The Detroit is about 6 years old and if you have a look at the design you will ALWAYS get more backlash than a standard diff centre, all in a driveline that already has too much.

I did qualify my statement with an 'almost'.

Originally Posted by djam1

The Detroit is a pain on side slopes and introduces a lot of backlash into the drive train.

Originally Posted by 101 Ron

The detroit doesnt dig holes in the sand or cause the vehicle to slip side ways on a slope........why would it as it is locked just the same as a manual locker when off road.

Can someone explain exactly why some LSDs and/or lockers cause problems on slippery side slopes? Which types are worse and why?

I am not questioning whether it happens or how much it happens. I just want to try to understand why.

Originally Posted by JC Rover

I've heard the true trac works very well with traction control. I'm about to get one for the rear Sals on the defender. Most of my off road driving is on sand. Where is the best place to get one? USA?

Jono

I have an Ashcroft ATB in the Rear of my D2 with TC and it's seamless, quiet and have never noticed TC operation on road even while u-turning it tightly. You can feel it working off road where there will be a slight pause in momentum until it sorts itself out and thing start moving again (esp with the auto) but I'd add one to the front as soon as I have the budget.

Originally Posted by vnx205

Can someone explain exactly why some LSDs and/or lockers cause problems on slippery side slopes? Which types are worse and why?

I am not questioning whether it happens or how much it happens. I just want to try to understand why.

Lockers make the wheels turn at the same speed regardless of traction or speed. When the ground is slippery, this can mean both wheels are slipping even at idle speeds. Add a side slope to the slipperiness, and both wheels will be slipping in the direction of rotation AND down the slope parallel to the axle. With open diffs, the torque goes to the wheel with less traction so it slips while the other wheel stays still meaning no slip in any direction.
LSDs don't tend to display the side slope slipping unless they are particularly aggressive, so a tightly adjusted clutch type LSD or a spool that locks up might display the characteristic when it activates, while a geared LSD such as Trutracs or ATBs which don't lock up at all will require a lot more throttle to get enough torque to both wheels for the same result.

Any locker be it automatic such as Detroits or selectable such as ARB, MaxiDrive, Jacmac will show the same characteristic, but selectable lockers can be turned off in these situations.

You can also see locked vehicles crabbing across rock steps as the wheels spin trying to find traction whilst unlocked vehicles will sit on the spot with one rear wheel spinning.

Thanks. It seems so obvious once it is explained.

I suppose one way of looking at it is you have a choice between both wheels spinning and slipping sideways or one wheel spinning and the other one just sitting there and while it might not help you to go forward, at least by sitting still it reduces the tendency to go sideways.

Originally Posted by vnx205

Thanks. It seems so obvious once it is explained.

I suppose one way of looking at it is you have a choice between both wheels spinning and slipping sideways or one wheel spinning and the other one just sitting there and while it might not help you to go forward, at least by sitting still it reduces the tendency to go sideways.

Exactly