Can anyone recommend a good synthetic lube for the differential and transfer case (2000 4Runner auto)? Also, what are the fill levels/quantity?
My mechanic owes me a favor so he said he could put it up on his lift and do it for free. I'll supply the fluids. He said he would also flush them out with brake fluid before refilling. Is this safe to do??? I've never heard of this.

The book calls for:
The front 75w-90
rear 90
Transfer 75w-90

I can't seem to find straight 90 gear oil. Is this a typo?
I think i'll just use 75w-90 in everthing (that's what the deal says they do).