I would start by draining the tranny fluid and replacing it. There are several posts here on how to do it. That may get you going for the cost of the fluid; otherwise you may be looking at bigger costs.Well i think the rear end on my L130 is going out .It runs fine till it warms up then it whines,starts slowing down ,then stop moving! once the rear end cools down i start all over agian... what do you think ???