I have a 1250 cub. My issue is with the hydrostatic transmission. The issue first started when my wife was mowing lawn and it seemed to not stay at a single speed (slow down and then speed up with the handle in the sam position). I checked the oil and it was fine (slowly seeping out the fill when opened). Now a few days later after using it it will not move at all (foward or reverse). Is this a pump issue or a filter issue or something i am not even thinking about. Any help at all would be greatly appreciated .