Thread: Review: Ashcroft LT230 ATB centre diff

So,
Have just returned from a corner country trip and considering the distinct lack of reviews when I bought this jigger I thought I would post one up.

This is what I am talking of:

Ashcroft Transmissions

Essentially a limited slip centre differential for the transfer case of landys that run the LT230.

To save reading all the below poorly written review the short version is, if you have a landy with an LT230 and drive on fast dirt (80-100km/h) just buy one.

Now the ramble.

My '95 130 tray back had a leaky transfer case from the good old wear induced oval of the case from the intermediate shaft. So I ordered up a set of seals, bearings and a Dave Ashcroft ATB centre diff. My rationale was that I spend a goodly amount of time on fast dirt but perhaps mostly that it would make "rebuilding" of the case much easier!
To fix the leak I essentially copied what has been done many times before, Noel (AncientMariner - http://www.aulro.com/afvb/modified-z...844-lt230.html) has previously documented this on AULRO. Turning up a 4140 collar for the "floating" end of the intermediate shaft that is pressed into the aluminium housing. This collar sealed very nicely using new 0-rings.

The case rebuild was relatively simple, having only pulled apart tojo cases I simply followed the LT230 overhaul manual... the only step I perhaps missed was taking insufficient care pressing in the front output housing bearing resulting in broken housings and a rescue trip care of Noel!

Anyways the case all got stitched back together nicely. I had intended to get the case and gear bag all back in and take it for a few hundred km trial run but work went spastic, I broke the housing, spent an inordinate amount of time increasing heat proofing and was waiting on delivery of a cooler for the R380 so in the end the ute was only stitched together on the Sunday prior to a Monday departure two weeks ago. The trial run was a 5000km roady !!! No scary noises and all went well in the first few hundred so I pushed on...

The route we took from Cooktown to Tibooburra was as straight line as possible incorporating plenty of dirt as you would expect. We did a loop through the Strez and Innaminka back through the corner and across to Currawinya before straight lining back to Cooktown. My theory is a dirt road at 80-90 is a million times more interesting than black stuff at 100 so taking station tracks and secondary roads makes sense to me. All up five grand or so with about 2/3 of that on gravel.

The ATB is freaking awesome on fast gravel. Full stop the end.

I am somewhat cut from a cloth worn by Rick130 (always keep your front bump stops shiny) and the control given of the ATB on gravel is fantastic. Obviously I couldnt directly compare to a truly open centre but from what I recall the ATB controls front-rear shunting (most notable on skatey corrugated fast open corners) brilliantly. It gives a very direct and even and safe cornering attitude with no significant or ugly looseness. I had to try really really really hard to get the rear to step out of line. In all honesty this simple modification is a major safety feature. Unlike an open centre it is really hard to get into oversteer on a loose corner.

I spent a bit of time generating a direct comparison between ATB vs locked centre diff. Previously I would always lock the centre on fast gravel to give more direct cornering (and obviously protect the diff). One issue with a locked centre is a tendency to push understeer. This was very noticeable flicking between locked and ATB on the same road surfaces. I preferred ATB by far on fast gravel. The other big difference between ATB and locked is on particularly uneven road surfaces, potholes, dust holes and whoops. A locked centre will tend to grab either the front or rear axle which ever finds traction first, this gives a shunt and introduces unsteadiness to travel. The ATB over the same surfaces seems un-fazed by these effects.

All in all I am stoked with the ATB and would recommend it.

Now a few details for those that care:
-Neck wrunged 300tdi 1995 130 defender.
-Barwork, winch, alloy tray, roof top tent.
-Would have been at about 2800kg.
-Averaged 13L/100 (actual km not speedo estimate)
-235/85R16 Bridgy muds running 30psi cold font and 42psi cold rear.
-Bilsteins allround - only noticed fade at the end of a 900km day with 650km on dirt.
-Rear Springs OEM main coils with polyairs inside
-Front Springs Kings ~220lb/in (old and worn)


Tomorrow the plan is to change out the t-case fluid. Obviously will look for obvious contaminates but dont expect to find anything too dramatic.

Steve

Originally Posted by Ancient Mariner

You just don't drive it hard enough to break things.
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Cheers
Slunnie

Maybe you don't drive hard enough to need one

AM

You hung on to that one didn't you! But possibly!

It sounds like good option so the centre diff doesn't keep wearing but with drive benefits.