Rebuilding LT230 - advice appreciated

[MacManMike]

Hi All,

First post for me and I'm straight into the serious stuff!

I am in the process of rebuilding a spare LT230 transfer (and eventually a spare LT77) for my 3.9 V8 Disco.

I have completely disassembled the LT230 and checked everything. Bearings were OK, non looking excessively worn, but I will be replacing all bearings with new.

Centre diff - looks like I will need a new gear set. The internal running surfaces of the planetary gears are all ridged and worn, there is some minor blemishing on the hard facing on two of them. Not cheap, but not worth NOT doing considering I am re-racing the box - they'll be toast in no time. Shafts to be replaced also.

Can you give me any advice on the following to do with the forks, fingers and dogs (bearing in mind the figures are in $AUD:

1) High/Low selector finger #FRC7929 - should measure 15.90mm - 15.95mm, measures 15.87mm. Only just too small. I reckon I can get away with it because it's not a super critical dimension anyhow.

2) Diff lock selector fork #FRC6109 - should measure 7.92mm - 7.97mm, measures 7.85 on thinnest finger. It's a $180 part - inclined not to replace it. Would you?

3) Diff lock dog clutch #FRC5440 - groove should measure 8.05mm - 8.20mm, measures 8.26mm so only just outside allowable. No signs of damage to dogs. $160 part - inclined to make do.

4) High/Low selector fork #FRC5458, superseded by #FTC2827 I believe - should measure 7.37mm - 7.47mm, measures 7.13mm so well under. Price unknown, most suppliers here do not carry them. Can deal with slightly floppy shift lever feel.

5) High/Low hub & sleeve #RTC4373 for D suffix, groove should measure 7.50mm - 7.60mm, measures 7.66mm. Wear pattern shows VERY little low range use and no damage to the the teeth on the dogs from rough changes or jumping out. Looking at the wear pattern, even with the worn sleeve and shift fork, the engagement still looks to be more than enough to prevent jumping out of high or low range. There are small lips (0.1mm or less on the hub where the sleeve sits in the high range position. $240+ parts to replace...

So, would you think it unwise to reassemble with ONLY new centre diff gears and the diff set up properly? At these prices (something like $AUD 700-800!) I can't believe that any of the local commercial rebuilders would be replacing the other parts for change-over units which presumably they get as total failures full of unhappiness when handed in.

Also, how often do these boxes go back together with original shims and new bearings to give correct preloads? None of the local parts suppliers carry much in the way of shims and they all claim they never have much calling for them. Either NOBODY seems to give much thought to set up or they do go back to original spec reasonably often.

Thanks in advance. Already spent a few evenings digging through all of the info on the site already - plenty of good info and projects you guys get into!

[FridgeFreezer]

Also, how often do these boxes go back together with original shims and new bearings to give correct preloads?

I don't think they get rebuilt very often if at all, round here a 2nd hand LT230 is £50-£100, or you just give Ashcrofts a ring for a new one or a recon job. It's usually just output pinion bearings, input gears and oil seals that go. Centre diffs go occasionally.

[MacManMike]

I don't think they get rebuilt very often if at all, round here a 2nd hand LT230 is £50-£100, or you just give Ashcrofts a ring for a new one or a recon job. It's usually just output pinion bearings, input gears and oil seals that go. Centre diffs go occasionally.

Hi FF.

No go - I am in Australia! Rebuild it is.

[MacManMike]

Any more thoughts?

[MacManMike]

I've taken a heap of pics of the disassembly so far:

LT230 pics

[Jon White]

I rebuilt mine recently. IMHO if the centre diff gears are worn find a better transfer box. The first one I stripped had very worn centre diff gears so I scrapped it and found a better one.

I replaced all bearings, and the input gear as the splines were worn, but otherwise simply picked the best bits of the two boxes I had and re-assembled.

I found I had to completely re-shim mine. I also had to fiddle with the thrust washers in the centre diff to get the correct pre-load.

Jon