ok so i just got my 33s installed today and they guy at the shop was telling me that i should replace my diff and tranny fluids. he told me BG is the best but didnt tell me what type of tranny and diff fluid he was usinf. i told him for the tranny i only want ATF4 and for diff he should use GL-5. am i right or is there something better?
__________________ Getting stuck is never an option
33" GY DuraTracs
3" Zone lift
Engo 12k Winch
built in air system
Previous posters are correct in that upgrading tires doesn't necessitate a fluid change.
However, if you have no idea when they were last changed, you should probably change them. That said, I wouldn't pay someone to do it. For the cost of fluids and an hour or two of your time it can easily be done.