Thread: Discovery 2 - Traction Control vs Front and Rear Lockers

A number of years ago I was offered the latest Disco to test drive, I jumped at the opportunity, traction control and all the fruit, took it to my favourite test site and tried on numerous occasions and methods to climb and navigate the cross axle sections with a big nothing, I was most disappointed, took the Disco back, got my old Disco with front and rear diff locks and did the same first time without any effort at all.
I came away thinking that Rover had lost the plot with their blurb about traction control being "the be all to end all".

Originally Posted by rick130

I've heard rumours that the the bellvile washers can crack in the ATB, which explains the noisy, clanking scenario.
Quaife's apparently are bullet proof

The bias ratio is something like 2.1:1 on most of Quaife's diffs and I'd be assuming Ashcrofts, although I've read 2.5:1. (Dave A?)
Eaton claim up to 3.5:1 with the Truetrac but what models?

Way too many Champagnes tonight to talk of gear pitch angles, end plate coefficient of friction and gear oil and their effects on bias ratio

The Ashcroft website lists the ratio as 3:1 where it also states that the Trutrac is up to 3:1

Must say for me I see more merit in the full time action of the ATB up front over the part time locker with the option of left foot braking where it may be needed and happy to pull the vehicle out with a winch if it gets too much!

Re the video must commend someone taking the time to do it but after watching too many videos in Covid lockdown do think came off the throttle way way too early to give TC a proper crack at it, plenty of other videos out there up more extreme slopes / conditions where the TC is working hard but the vehicle keeps going whether the front or rear are in loss of traction situations. In all cases the throttle is kept constant and the wheel is easily seen to lock unlock one or multiple times.

Do not think I am in anyway underrating the effects of either ATB or Lockers here, I am fitting ARB back and Ashcroft front to my TD5 for the same reasons as others which will I am sure make the D2 walk up where my D1 got up but worked reasonably hard with only the aid of CDL. Tempering this is the fact that most of the explorations of lockers are done where vehicles are driven and one wheel spins incessantly, no action of TC happening at all which would transfer power to the stationary wheel (which is what the locking does) and provide some forward motion at least.

One other consideration when viewing any of these videos where supposedly the same are driven up hills is yes the locked will get you further (I am not disputing that) but in some of them, airing down would get the dud there as well. The higher the air pressure the more advantage a locked wheel will have against an unlocked or TCéd vehicle.

This all of course has to be tempered by where and what you will be driving on, ahhhh comparisons, they always give me a smile.

Originally Posted by Slunnie

but I would continue to encourage the Detroit Trutrac ATB as it has a more positive bias ratio and doesn’t have the wear issue.

I'd go beyond this and recommend for the rear your skip the ATB/Trutrac and go straight to the Detroit. While I've no first hand experience running an Eaton Trutrac, I've run the Ashcroft ATBs, which are the same type of product by a different brand, and am now running the Eaton Detroit - the positive traction increase is significant with no ill effects for normal daily driving use. I just cannot see a reason not to go straight to this level when you get so much more for little additional cost.

Originally Posted by jezzarezza

Sorry to hijack the OP but this is the first negative couple of posts I have seen in the Ashcroft ATB.

You are not looking hard enough as there's a number of posts and a few threads out there now.

Originally Posted by jezzarezza

Is this “wear issue” the same for front and rear diffs?

Yes, as front and rear are the same units for Ashcroft ATBs. Eaton Trutracs use different parts front and rear.

Originally Posted by jezzarezza

As the detroit is a similar price to lockers I’m weighing up my options...

The Eaton Detroit is a locker. I assume though when you say 'lockers' you are referring to selectable lockers such as eLockers and air lockers. While the diff centres might be similarly priced, the Detroit doesn't require other complications in the installation (solenoids and electrics for eLockers or air compressors and air lines for air lockers) and therefore has labour, effort and additional component cost savings. Also a less complicated piece of equipment with less parts and bits to go wrong. And has positive always there traction assistance not only when turned on.

Originally Posted by Slunnie

To clarify, I am a fan of Ashcroft, I run some of their kit, but I’m not a fanboy and see products for that they are.

I likewise run and have run a number of Ashcroft Transmission items - at the height I had their Td5 Heavy Duty V8 Torque Converter, Heavy Duty front CVs, heavy duty rear axels, front, rear and centre transfer case ATB. I've since removed the front CVs as they were a reliability nightmare (firstly with the boots kept having issues requiring full dissemble, clean, regrease and fit, and then later in their life the spiders and basket had some wear dimples causing clicking and requiring redressing and replacement components) and the rear ATB has been replaced with an Eaton Detroit.

Originally Posted by Slunnie

The wear surface conversation I cant find in a search, I thought it was interesting, I haven’t stripped one. TWR7CX might be able to tip in some real info here.

I didn't strip and inspect the ATB that removed. But I can say that I originally fitted the ATBs circa 2013, over the 6 years of use their performance decreased. They were great when originally fitted.
For a while this performance degradation was my own fault. I had been running semi-synthetic Penrite ProGear gear oil which has LSD additive (note that ATBs are a type of LSD) this seemed to make the oil too slippery and reduced the ATB performance. Changing to the standard mineral Penrite gear oil without LSD additive resolved this.
However over their life they just never amounted to what they were originally. If I was to purchase such a product again I would only consider the Eaton Truetrac version (they're a much larger company that have been specialising in such items and making the Trutract for a wide variety of vehicles for a long time now). If I ever have cause to dismantle my front diff again I will swap it out to a Trutrac just because I've lost my trust in the ATB there.


A recent dune driving trip in our MY12 D4 reminded me why traction control can sometimes be a negative. We struggled up some of the larger hills as the car was self braking (traction control) costing the power needed to do the run. With the traction control turned off, flew up the hill without an issue!

Originally Posted by twr7cx

A recent dune driving trip in our MY12 D4 reminded me why traction control can sometimes be a negative. We struggled up some of the larger hills as the car was self braking (traction control) costing the power needed to do the run. With the traction control turned off, flew up the hill without an issue!

Dont you mean DSC?

As far as I am aware TC cant be turned off in D4.
I never had any issues once DSC was turned off, in the softest of sand, mud,or any off road driving.

Some of those E lockers dont work in reverse, which can be a PITA,at times.
Where the air lockers will.

Originally Posted by scarry

Some of those E lockers dont work in reverse, which can be a PITA,at times.
Where the air lockers will.

Stephan did a really interesting review on the lockers and then made a seperate video specifically about the problems with the E-locker.

E-locker vs ProLocker vs Airlocker


E-locker issues.