Thread: Transfer box service

Hi all, thought I'd share a few pics from stripping down the LT-230SE transfer box (2001 model with diff lock lever added). After nearly 250k km I had the usual leaks from intermediate shaft seal and input seal, and after a trip from Brisbane to Sydney the oil leaks were bad enough to find a weekend to get the job done. Thanks for others who had posted information on this site that helped, and I have added some of my own learnings to anyone interested. By the way, you really need two people unless you have a well-kitted-out workshop - thanks also to my dad who helped.

1. I built a cradle out of wood to support the transfer with a trolley jack.


2. There are 6 bolts holding - two in front; and 4 at the rear (for some reason they don't clearly identify all 6 that need removal). I used the guide bolts from M10 x 180mm with head cut off to allow the transfer back sufficiently to clear the input shaft. 200mm bolts were a little tight with rearward movement I found. The removal of the exhaust silencer was really helpful. Leaks were obvious at this stage from the input shaft and intermediate shaft (front side).


3. Surface cleandown on the bench.


4. Covers removed. This is where I started to find lots of the suspected brass pieces spread through the gearbox from the centre diff shims. I had already purchased some replecements in anticipation that these usually wear out.


5. Case stripdown. It was clear it needed a good cleanout. Intermediate shaft had signs the bearings seats were spinning on the shaft itself, and needed a retorque. Gears themselves are in good condition with machining marks still evident.


6. Center diff stripdown. The bearing on the front end (front drive shaft to RHS) has to come off with gear puller, otherwise only an open-ended spanner can get to the centre diff bolts. It came off fairly easily and gives proper access to the bolts so they can be retorqued later.


7. Inside center diff. Quite a bit of play was noticed between the front/rear output shafts. Its clear once apart why - the planet gear shims completely gone (brass) except for one which is only paper thin. Two planet gears had some signs of scoring on the casing. New shims made diff feel properly tight again. Have to take careful notice to put each piece back in the identical position.


8. Back together with new oil seals. The intermediate shaft was tight in the casing and did not seem to have the 'oval' some people say happens to the casing over time, which the seals do not fix. So I decided to put back together with suitable amount of RTV sealant in addition to the seals. Keeping the nut-side o-ring in place while assembling was tricky and I recommend having a spare (my first one unseated and was damaged during assembly).


Back in the vehicle is now a noticeably smoother drive with much less backlash than before, and most importantly no leaks! Job took two full days and two evenings.

Anton

From memory oil seals are around $8 each and I used the Corteco brand as I didn't want to be doing it quickly again. There are 3. There is also a seal kit that includes o rings and gaskets for under $20. I did not use the gaskets as they don't seal as good as RTV. Diff planet gear shims were only a few dollars. I bought parts from Island 4x4 in Kent. Spare o rings were from local bearing supplies shop. The most expensive part is the oil - I chose the Transmax at about $25 per L.