I just bought this mule. It is an 04 Mule 550 and looks to be in excellent condition with 300 hours on it. It cranks and runs great and has good speed but if I start up a substantial hill with much of anything on it, it will not climb the hill. Engine is still reving and running good but it just will not climb. There is no skip or anything like that. I assume it is an issue with the primary clutch. I pulled the cover and the belt appears in good condition. Im curious if the clutch can be rebuilt or should I just bite the bullet and replace it. Any help on this issue is appreciated.