50kProbably 50k since last change, But didnt see the plug. I guess time dependant as you say.
50k10k is long enough
I do mine, 300Tdi Disco R380 manual, at about 10k, but recently I've changed it twice in 10k due to extra time spent wading and such-like. I change diff oils about every 4k, same reason, and transfer box when I do diffs 'cos it's the same oil!
breathers may help but in no way keep water out of axles ,seals are designed to keep oil or grease in not water out ,its very common for oil to be contaminated i check every time after wading and change frequently , a good % of my work comes from people that dontBlimey read manuel in sure diffs are 24000 or two years whatever sooner you got money to burn with correct breathers shouldn't be water in them and you don't need to drain the whole lot out to check eek
breathers may help but in no way keep water out of axles ,seals are designed to keep oil or grease in not water out ,its very common for oil to be contaminated i check every time after wading and change frequently , a good % of my work comes from people that dont
it does once settled but you do see evidence on bearings after a very short period of time
Blimey read manuel in sure diffs are 24000 or two years whatever sooner you got money to burn with correct breathers shouldn't be water in them and you don't need to drain the whole lot out to check eek