Thread: BW transfer case oil change interval.

I just did a full service on my 92 prior to a long trip to the Flinders Ranges.
One thing I noticed on my 142K car was that the oil in the transfer has got dirty very quickly.
I changed it last about 25 K ago using Transmax Z, yet when I dropped the oil it was pretty discoloured, which surprised me. Still green but army green rather than lime green.
I have changed to Transmax Z again, but I will change it about every 20K as it looks like the chain wears quite a bit and puts the dust/bits in the oil.
On the surface you would think that the oil should stay pretty clean as it does in a diff.
So I think regular changes will lengthen the time until the chain starts hitting the case.
Regards Philip A

If you havent changed it in ages all the mucky bits from the old oil tend to stick to the sides.

driving it before draining will help some but draining it filling with cheap auto oil driving it a few Ks then draining it before adding your new top of the line oil will get more out.

of course flushing with your top of the line oil will yield even better results.