300tdi oily transfer-box

Hi all. 1998 300 tdi manual g-box. Recently acquired. On dropping all the fluids no-where near as much oil came out the transfer-box as should have. Refilled it all `n` it seems to be leaking from the seal between the main-box `n` the transfer-box. It`s golden in colour not red so must be from t-box. The main box level is holding good. Bit of a whine from the transmission on the over-run too. I`m thinking it`s time to get a replacement t-box box lined up, drop the t-box off and replace it rather than try and repair the old`un. I`ve seen some threads on here saying it`s do-able but not pleasant to drop the t-box off seperately. As I think the main box is ok I don`t want to drop that out if I can help it.
Sorry about being long winded in this query, but is my diagnosis likely to be correct and the repair likely to work?
Ta in advance.

Its not a bad job at all to drop the transfer box.

It,ll be the main seal into the box thats leaking. ( about £8.00 for a new one ).

I took off the front and rear prop shafts,front exhaust, ( 5 bolts ), front cross member, ( TD5 ), hand brake drum and backplate, linkages and cables and loosened the mount bolts.
Undo the 5/6 bolts and nut and slide it back of the main gearbox shaft. ( and fall onto your chest, winding you ! ).

While its off you can change the intermediate shaft " O " ring seals as well. ( if theyre leaking ).

Get someone to help you, especially putting it back in, and dont snag the new seal when sliding the transfer box back over the main shaft.

I,d imagine thuis would be 10 times easier than taking the 2 boxes out together.

Del.

Thanks for the answer. Much as I was thinking, but best to ask before getting under it. (especially in this weather!)

Afore ye do anything radical with the Transfer box, check that the breather tube is not blocked, it runs from the top of the Transfer case up into the engine bay, LH side I think and can dislodge from the clips that retain it and in some cases be burned shut on the exhaust manifold, mine did, ('97 Disco 300Tdi), both it and the Gearbox breather that is with it, I could not keep oil in the transfer case, gearbox not so bad, cut off burned seared shut ends, and checked that tubes open, (remove fill plugs and blow through tubes from engine bay), bingo!! no more oil leaks, a lot easier than what you're contemplating, good luck.

Great! Thanks. I suspect I`ll be dropping the box soon anyway, because of the whine, but well worth checking.