Intresting thing turned up on my limited today. We have had a long trip, 7 hours, 600k..
Two hours into the trip i noticed at 98-106kmph the rear diff started to whine. It seems to be only on cruse and acceleration. Coasting down it quiet.
I had to swap to Redline shockproff due to boiling most fluids that i try due to the heavy towing we do (horses)
This is the oil i have put in, Which was recomended by lots of the 4wd specialists. http://www.redlineoil.com/product.aspx?pid=44&pcid=8
The crazy thing with this diff whine, Its quietish. But only located where my driving possition is. I move my head forward, its gone. Move it so the side, its gone. Drives me insane lol!
Im starting to think, that maybe i should of got the lighter graded stuff. The wierd stuff with redline is the ratings seemed to be measured diffrent