After talking to mike he told me i should use 85w140 but i cant seem to find it in synthetic anywhere. Anyone know where i can buy it? or is it ok to just use regular

 

You'll probably have to use 75w140 if you want synthetic in a normal brand.

You don't actually have to use synthetic. I think D2 specifies it just to increase the change interval. The differential is the same as in the D1, which doesn't specific synthetic.

 

Royal Purple if you must have synth
Royal Purple/Synthetic Max-Gear oil SAE 85W-140 1 qt. (01303) | Gear Oil | AutoZone.com

 

I do not think you really gain anything with synthetic gear oil. go dino get the heavy stuff and change it every year or after deep water crossings. the expense of the syn for me is just not worth it.

 

ok im just gonna use regular no where in little rock sells synthetic