What year? There is a huge difference in the 1100 and the X1100 transmissions. Also how many hours on the machine? How many hours on the transmission fluid? And just to verify, are you using UDT or Super UDT? If you would like assistance you need to be as specific as possible, also when asked you will need to provide pictures or you will have a hard time getting help. These machines are real work horses but they require proper maintenance, at the required time. Failure to maintain the transmission properly can get quite expensive. The used X1100 that I brought home in milk crates, the hydraulic fluid was not changed in accordance with the user manual, had a catastrophic failure of the Hydrostat which damaged the case. Cost to repair was over $6,000. I would imagine the 1100 would be more expensive to repair due to the transmission and the hydrostat sharing the same case and is not the current model which seems to drive the cost of new parts up.