I have a 99 Suzuki LT F250 and am having some issues with my transmission slipping. I put synthetic oil in last year in hope of extending its life, but this year I noticed the transmission slipping when I start out and if I give it a lot of throttle. It seems to be worse in high range. I mainly use it in low range to run around with the kids and pull my cart. I just switched back to regular oil which one of the guys at the dealer suggested but it still slips just seems to be a little better. Anybody have a suggestion.