I just notice little leak from transfer case, leak starts only when engine is running, bu my question is. Transfer case is connected together with gearbox oil system ? Or oil is separated ? and how to check the level of oil in transfer case. Many thanks for answer and I appreciate the answer.

 

Andrew: Below are several threads about the transfer case in our X-Types, which helped me change the oil in mine recently.

The transfer case has ~600ml gear oil, which is separated by seals from the transmission fluid. It was designed to be "sealed for life", but that caused problems. So the clever people of this forum came up with a few ways to drain and refill it, typically with 75W-140 gear oil.

I'm no expert, but after studying these threads, the oil leaking from your transfer case could be caused by:
1) Overfilling it - the excess oil would overflow from a vent on top of the transfer case
2) A worn seal - allowing transfer case oil to leak out. Need to fix this before the transfer case fails, stranding you on the side of the road with a labor intensive repair.
3) A worn seal - allowing transmission fluid to leak into and overflow the transfer case. Seldom mentioned in the threads, but apparently it can happen.
4) A cracked transfer case housing - apparently can happen, but rarely mentioned in the threads.

I've quickly exhausted my limited knowledge of transfer cases, and will let the experts guide you further.

Suggest you clarify the mileage, automatic or manual transmission, and any recent maintenance on the transmission and transfer case. It would also help to describe where the transfer case is leaking (pictures are even better), and to drain the transfer case to see how much fluid comes out (should be 500-550 ml) and if it's just dirty gear oil, or possibly mixed with transmission fluid (hopefully not).

Tilting the car is sufficient to drain and refill the transfer case fluid. It's not required to add a valve and drain hose to the transfer case, though some people do this for long-term maintenance benefits. See pictures of both methods in the threads below.

The more information you provide, the better the experts here can guide you.

https://www.jaguarforums.com/forum/x...solved-139757/

Transfer Case oil change

new , used x-type . looking to change all fluids

Transfer case prop (drive) shaft bearing P/N's

http://sitemaker.umich.edu/ancient.s...bojangles_.ppt

https://www.jaguarforums.com/forum/x...-point-105687/