Well i put new cv boots on the rear of my 06 450 and when i pulled the axles i lost some lube what do i need to replace it with

 

In my opinion your best bet is to drain and refill with full synthetic gear lube. I use 75-140w full syn gear lube. According to my mfgr that is good and will replace anything of any other weight. The syn lube is thinner but far better protection and less roll resistance. Most all the mfgrs approve a full syn 75-140 diff lube.

 

I would probably use 80W-90 if I have it on hand.