How hot should the rear diff get?  I have had the problem of oil puking out the vent tube.  I changed it and there was water in it.  I put the correct amount in and kept watch.  The oil has not come out the vent tube but, the rear diff to the touch is very hot?  Any ideas or suggestions.  Thanks

[2015 Z Force 800 53/Trail EPS]

If it had water in it there may be bearing or gear surface damage that will cause additional heat. Time will tell but mine also gets hotter then I think it should and I use synthetic lube. I can't hold my hand to it more then a couple of seconds so I guess they do get hotter then others.

Thanks -  That's where mine is.  Too hot to touch for more than a few seconds!

If you had water, change it again after a bit. Synthetic oil will help too.

mix a little kerosene with the diff fluid and run it a bit then drain it.  It will get the all of the water out of it. 

My front diff would get water in it from the vent tube and that is what I had to do,