Not hard but you have to be good with the tools.

Get the new transfer box rebuilt with new bearings and seals through out as the next problem will be the work and age hardened intermediate shaft "O" ring seals that leak and then get them to fit it for you, trust me, it's worth the money unless you have a 4 post lift and a tranny jack.

 

I have an 03 also and I'm looking at this in the not too distant future. I've asked before but never got an answer. Can you drop the transfer case with the exhaust in place or does it have to be removed? Rave says remove...

 

 

 

i have been pondering the process of installing the cdl from my '99 truck into the '03, so i've been referring to this write-up:
https://www.scribd.com/document/1611...te-Up-03-20-09

i also did a bunch of reading about the pros and cons of doing just the front output section versus the entire t-case. there are proponents of both approaches, of course. some argue that it can be difficult to really align the internals of the front section to the main body of the t-case and you end up with excessive whine or other noise, or possibly unnecessary wear.
switching out the entire t-case gives you the opportunity to refresh all the seals to minimise any leaks. however, if the donor case is from an earlier year, it won't have some of the internals reinforcements and other modifications that were implemented later.

my personal thinking is that when i get to the point of doing my own swap, i will pull both cases and refurbish the internals of the '03 box, as well as switching the front output section from the '99 to the '03. i hope that because i will be doing it off the vehicle it might be a little easier to ensure everything is lined up properly.

 

I rebuilt my transfer case last year.... It was a lot of work. The tolerances you're talking about are thousands of an inch. Need micrometers, a few special tools, dial indicators, press, etc. The bearing preload has to be perfect for the center differential, intermediate shaft, and input gear. Swapping front output housings is a roll of a dice whether the preload will work or not.. At best, imo, you have a transfer case with a shorter life, and at worst it'll blow out in ~200-500 miles. A few people have done it and claimed it worked... but again, if the preloads are wrong, the transfer case will still work, just not for long - not sure how many people post back if it fails down the road. There are something like 15 different shim sizes for the center diff... gives you an idea of how likely swapping front output housings will net you the right preload

Like nigel said, the primary leak point is in the intermediate shaft and o-ring, less so the various covers. In order to replace that o-ring you have to pretty much tear the box apart. The box doesn't use any gaskets... it's anaerobic sealant all the way around.

IMO just swap in another box, reseal the covers if you know they're leaking, and be on the road. Or if you want to have some fun and have a hundred hours to spare, rebuild it with new bearings, seals, diff spider gears, thrust washers, HD cross pin, shaft, etc. Land rover toolbox videos on youtube has some great videos on it, RAVE has a complete overhaul section (but it's impossible to follow without a few special LR tools)

The best transfer box is from the '04, it has CDL, interlock solenoid moved to the shifter, and I think quieter/better gears

 

 

 

when i installed the linkage in my '99 i did it from inside. since you have to remove the entire central console anyway it's not a problem.