how often do you guys change your trans and rear fluids? i'm toying with the idea of going synthetic. it cant hurt. keep things cooler and better lubricated.

 

I have used synthetics in my tranny and diffs for a long time. It is a little more expensive, but requires less frequent change intervals and Eaton, for one, will automatically extend their warranties from 500,000 miles to 750,000 miles if you use synthetics. No brainer for me. Eaton recommends a 500,000 mile lube change interval with synthetics. I change mine at around 300,000 miles. Probably could go longer, but that is my comfort level. I use a brand on Eaton's primary list, Allied Oil. I get all my tires, oil, and lube from Allied and get pretty good pricing.