Transfer case

As others have said, the LT 230 transfer case is pretty robust but it does have a couple of issues. One is failure of the centre differential side washers adding to slop in the drive train.

For those that may be unfamiliar the LT230 transfer case looks like this.

Attachment 139059

The centre differential assembly when removed from its housing looks like this

Attachment 139060

And when pulled apart looks like this

Attachment 139061

Inside there's a conventional spider gear assembly and two piece cross pin with (bronze?) side/thrust washers. Drive output (front and rear) is via the two (larger) side gears which fit into the differential case with a fibrous thrust washer/shim in between. The fibrous side washers come in differing thicknesses so that correct meshing of the gears can be attained.
When these shim washers wear/disintegrate the result is slop in the centre diff/drive train. The bronze side washers shown in the above pic are new ones.

Attachment 139049

It is very common to find the side washers worn wafer thin or totally disintegrated when pulling a centre diff down.

Attachment 139055

This is what the inside of the centre diff housing looks like and in this example the wear is very slight. Replacing the side washers when excessive centre diff slop first becomes apparent is a fairly simple and cheap exercise. The bronze side washers are only a couple of dollars each.

If you leave it too long you can end up with something like this.

Attachment 139056

This centre diff housing is IMO verging on un serviceable. Not only has the shim washer worn deeply into the housing (before disintegrating) the back surface of the spider gear has also worn deeply into the housing. Whilst it's possible to fit two bronze shim washers here to compensate for the wear I've reservations as to how long they would last, though I've not tried it.

Here's an alternate 'fix' that one member here is trialing. This is the same badly worn centre diff assembly fitted with larger diameter hardened steel shim/side washers between the spider gears and the standard bronze shim/side washers.

Attachment 139057

This picture also shows pretty well how the spider/side gears mesh together as well as the selectable thickness fibre shim that is chosen to 'set' the correct mesh and thus minimise slop/backlash in the centre diff.

Deano :)

the standard diff pins can go bang!
But they usually just wear out first and cause wind up in normal conditions.

Another issue with the LT230 is that the intermediate shaft wears an elongated hole in the TC housing allowing oil to leak out. This can be quite messy as a little bit of TC oil goes a long way and can affect both the aesthetics and resale as the vehicle. Here in Victoria the vehicle could be deemed unroadworthy. I've not seen one where the TC has run dry and failed because of this but with poor maintenance I guess this is possible.

Attachment 139062

This is the end of the intermediate shaft that can flog an elongated hole in the transfer case. This is a bugger of a thing to fix. The transfer case needs to be removed from the vehicle and totally stripped down before being attached to a milling machine table where the centre of the elongated hole is determined before machining the case to take a stainless steel insert like the one supplied by Ashcroft.

This is what a 'repaired' TC looks like.

Attachment 139065

With the Ashcroft supplied stainless steel insert fitted the TC housing is better than new. The above photo shows the end of the intermediate shaft sitting about 1cm proud of the housing to show the internal 'o' ring seal. It's a pity Land Rover didn't do a similar thing when this design fault first became apparent :(

Deano :)

Wow thanks for the write ups Deano. Mine is leaking also & I’m trying to decide whether to just do the seals or crack it open and do a complete rebuild. Apart from the leaks I haven’t noticed any issues. I’m planning on installing the CDL linkage next week tho. I still need to get a good look at it to see exactly where it’s leaking from.

Answers to a couple of questions please.
Is the wear on the CDL thrusts dependent on the amount of locked 4wd driving or will it still happen with tarmac miles.
With no oil contamination during their life what K's would you expect out of the thrusts with mostly tarmac driving.
When the thrusts are worn to the stage that they need replacing {not buggered} is the play that noticeable on the output flange compared to a good CDL.

Thanks for any replies.

Quote:

---

Originally Posted by whitey56

Answers to a couple of questions please.
Is the wear on the CDL thrusts dependent on the amount of locked 4wd driving or will it still happen with tarmac miles.
With no oil contamination during their life what K's would you expect out of the thrusts with mostly tarmac driving.
When the thrusts are worn to the stage that they need replacing {not buggered} is the play that noticeable on the output flange compared to a good CDL.

Thanks for any replies.

---

Not locking the CDL quickly enough is usually what causes the wear.

IMO the best fix for this is an Ashcroft ATB...

It also takes so much backlash out of the t/car it isn't funny.

The LT230 is definitely a strong bit of kit. At 300,000 I was naughty and took my leaking transfer box on a holiday on the Old Tele Track and went through deep water umpteen dozen times. If oil can get out water can get in. Got back and couldn't find time to check it for 6 months and when I changed all the oils the transfer bad water in it and was noisy. Flushed and changed oil but still noisy. I was lucky and got a box that looked like new from Hong Kong (guy that imported d2's is no longer doing so..) that had 20,000k on it for $300.
Cheers

Quote:

---

Originally Posted by John_D2

................. Mine is leaking also & I’m trying to decide whether to just do the seals or crack it open and do a complete rebuild. Apart from the leaks I haven’t noticed any issues. I’m planning on installing the CDL linkage next week tho. I still need to get a good look at it to see exactly where it’s leaking from.

---

If the only issue you have is oil leak(s) I'd suggest nailing the source of this first before considering a rebuild. Your Gerni is your friend here :) Common places to check are the intermediate shaft previously mentioned, bottom cover plate and the also previously mentioned felt seal behind the front output flange. There are other 'opportunities' for oil to escape but these are the main ones to check. With the cover plate it's worth noting that the two bolts closest to the drain plug go through to the inside of the TC, the others are blind. A bit of silicon on the threads of these two bolts and under the heads of all the bolts is sometimes whats needed to seal this area properly. If the TC has been removed previously it is very easy to damage the input seal allowing oil to escape from here.

As to whether the TC needs a re build this depends on how worn it is which depends on how many k's and how hard they've been. My 'rule of thumb' here is if the intermediate shaft isn't flogged and the insides of the centre diff assembly case isn't badly worn I'd consider leaving well alone. The bronze side washers will need replacing if you've pulled it this far apart. Someone mentioned in an earlier post that it may be possible to remove the centre diff 'nose' in vehicle which isn't something I've tried but would save considerable time and effort in a simple centre diff 'overhaul'.

Deano :)

Just be aware if you pull the nose and replace the front bearing you should redo the preload on the front bearing, although you would probably get away with the stock shim already there.

That is why if you replace the nose with a locking one like I did, you have to swap the bearing and shim from the nose you removed to the locking nose. Mine seems fine.

BTW Loctite Thread sealant 547? is the stuff I use on the threads of the sump cover. I have fitted a big sump and it is as dry as.

Regards Philip A

Quote:

---

Originally Posted by rick130

Not locking the CDL quickly enough is usually what causes the wear.

IMO the best fix for this is an Ashcroft ATB...

It also takes so much backlash out of the t/car it isn't funny.

---

So there's a good chance that most of the non-cdl D2's (if they've done much dirt road/sand/offroad) would be in the line-up for a rebuild after 200K or so? (Mine's got 310K on the clock, but doesn't look to have done much off bitumen at all)