Diff and gearbox oil

[Jozi]

Any one got recommendations for the above?

Box is of an m42 and from memory a lottle notchy going in to 1 and 2ns when cold.

Diff is a lsd with 40% lock. Wpuld ot be wise to rin some cheaper oil in the diff and change it after a few miles?? Reason being that shes a little stiff after some water got inside her when i did the electrolysis a few weeks ago.