Thread: LT230 @ 250k behind a Td5. Things to look for?

Just did mine as a precaution at 201000 ks and found the following.

The casing was fine not being worn at all
The centre diff needed washers but I put in new gears and a one piece cross shaft.
The Ashcroft kit was perfect for the job with only premium brand bearings supplied.

The car is now very quiet and the absence of backlash is a true blessing.

Thats the most common things with them, they are a strong box really.

Add to parts list, output seal and coupling shaft for auto and o-ring. The coupling shaft always has a wear mark in them from the seals. You can speedi sleeve if you want. Also check torque in extension housing mount bolts.

I think I'm pretty lucky in that it's not done much hard work in its life.
PO used it for towing a dog washing trailer, but it wasn't a particularly heavy one.
So far it seems like the leak is just from the cover plate, so I'll see if re-sealing that works for the time being while I get my goodies together.
There really isn't a lot of backlash in it atm and it seems pretty quiet so I'm just wondering if it's really worth doing at these kms in absence of any real issues atm.

Make sure you change the seals on the high / low range and the CDL selectors as well they are bound to be hardened by now

My experience comes from the Disco 1 Tdi300 LT230 so not entirely sure how different the D2 is.

Check the movement of the high/neutral/low and the diff lock.

As selectors move to different settings they are held in place by a ball bearing backed up by a spring backed up by a grub screw. To hold the selector in place the ball bearing sits in an annular groove matching the diameter of the ball bearing – nice and snugg. When the selector is moved the ball bearing is forced to rise out of the groove over a 'hill' to the next groove.

People have complained of the D1 jumping out of low range. Put the lever into low and give it a gentle tap back with the hand. If it moves back easily then the grub screw controlling pressure on the ball bearing needs to be adjusted tighter (or see next paragraph). If it takes a huge amount of effort to move the selector then the grub might be too tight. I do this testing when the box is back on board. Bit of a nuisance repeatedly going from cab to under the vehicle. I usually wind the grub right in (no movement allowed) and gradually back it off til movement feels 'right'.

I've also found what I perceive is another problem with the ball bearing system. I have found this in three centre lockers from D1s. From memory the diff lock ball bearing and grooves are five eighth inch diameter. The three grooves in the high/neutral/low are quarter inch but have also been fitted with five eighth inch ball bearings – there is no way the lever could be held securely in place because the ball bearings cannot properly 'nest' – you could see pressure marks on the flanks of the grooves where over tightening has occurred to try and compensate. So if you've wound the grub in and out but still can't get the nice firm ratchey feel then this might be the problem. Solution, pull out the ball bearing, measure it – if the wrong size visit wreckers or places like CBC or others that provide sprocket drives and chain (where I got mine).

Otherwise, yes Ashcroft gear. LR Automotive will also sell you a kit to deal with the coupling shaft(?) flogging the alloy housing but might need a machinist shop to do the boring.

As a rough guide I have found thrust washers OK 200-300 thousand kms, 400-500 very serious consideration for replacement – by 600,000km (yes one of my Disco has done this) the thrusts washers will be gone or thinner than cigarette paper. Depends on how hard a life and servicing intervals. There is a tendency for sediment to collect inside the centre diff and around the thrust washers – not sure if this adversely affects the oils ability to lube the thrust washers.

And of course there is always the debate as to when you should lock the centre when driving.

One other aside, I read articles on peoples concerns about fitting a single new same brand same model tyre to constant 4x4 systems that did not perfectly match the diameter of the older worn tyres (after say staking a tyre) and what affect this would have on the centre diff. Was told that this is a problem for viscous systems and not gear driven systems. Not that I would suggest a 35 inch spare to go with 29 regulars