Re: transmission/Hydraulic fluid. Who\'s using what?
LOTS of big earth moveing equipmnet uses motor oil in the hyds and tranny. I can look out the window into our equipment lot and pick out 3 big deer loaders, and some huge 80,000# scraper pans that use sae 30 in their tranny/hyd sump... pretty common.
Keep in mind that motor oil is designed to see a higher working temp than a regular hyd oil... just due to the fact that it is circulating insid ethe galies in the block, anround the combustion chambers.. etc.
If that is what PT specifies.. I wouldn't second guess their engineers... besides.. Like I've always said.. the PT's are closer to 'consumer' level heavy equipment, than to compact tractors.. etc.
Soundguy