LT230 backlash when diff locked

Sorry if this has been asked before, but I've bought a Disco LT230 to fit to my Defender. I'm going to rebuild it, but when checking things over before I do the complete strip down I notice that there's a 1/8 turn or more play between front and rear drive flanges when the diff is locked.

I can't find any figures for what is normal. Do I need to steal myself for a load of extra parts on top of the bearings and shims and gaskets I've already ordered?

there is some play as locking collar has wide gaps between the teeth to enable easier locking and unlocking

Thank you. I guess I’ll examine the various splines and then the teeth etc on the locking collar carefully when I’ve got it all stripped down.

j_g_uk said:

Thank you. I guess I’ll examine the various splines and then the teeth etc on the locking collar carefully when I’ve got it all stripped down.

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i doubt youll find an issue there you may well find one in the center diff itself ie worn cross shafts and planet gear thrust washers

The next question is whether the Ashcroft heavy duty cross shaft and matching planetary gears are worth it...

j_g_uk said:

The next question is whether the Ashcroft heavy duty cross shaft and matching planetary gears are worth it...

Click to expand...

a rebuilt std diff is fine

Ok. Fingers crossed for when I strip it down. It certainly all feels smooth and no obvious problems I can feel or see with covers off.

I’ve ordered bearings and gaskets and shims so hopefully it’s just a straightforward rebuild.

Case is on its way to being clean and shiny on the outside. I’m just wondering whether I’m brave enough to put it all in the dishwasher when Mrs M is at work.

I might try our local engine rebuild and see if he’ll put the cases and bits through his washer...

Ideally I need to try and source a knackered R380 mainshaft that I can cut down to make an equivalent to LRT-41-005. (It’s the tool that goes into the main shaft of the LT230 when you’re using a torque meter to check the preload of the bearings in the layshaft as you collapse the spacer inside it.) I know the trick of using a spring balance and bit of string to measure the preload torque but I think I have access to a torque meter so if I had an old R380 mainshaft (even if the splines are a bit knackered) I can turn up something that looks like the official Landrover tool and do the job exactly as per the book.

(I’d put a wanted ad in the right bit of the forum but I’m still short of the fifty posts required...)

j_g_uk said:

The next question is whether the Ashcroft heavy duty cross shaft and matching planetary gears are worth it...

Click to expand...

I put a HD in mine but that’s more because I wanted to upgrade as best I could. If JM says a standard will be fine the. A standard will be fine

Thank you. I still live in hope of finding an old defunct R380 mainshaft kicking around someone’s workshop.

Supplementary question:

I'm confused regarding the setting of the pre load on the intermediate shaft. The Landrover official manual says to take out all play in the shaft and then tighten the nut until the torque on the input shaft has increased by 10 ft/lbs. One video clip on Youtube suggests that's too much and he's always result them by nipping up the bearing to allow a particular increase on a spring balance pulling a string that's rotating the input shaft.


The video shows the man using the Landrover official technique and then suggesting that it's too much.


He also quotes Ashcroft who say they take all the play out and then 'nip it up a little bit' (or something like that?)

I've got a torque meter and I've got a small spring balance so I can choose what technique to use.

Any experienced suggestions or inside knowledge as to who is right?