FYI - I just found my muffler rattling badly and upon investigation I found the two bolts that hold the muffler bracket to the transmission missing. I had heard a funny rattle while driving, but the minute I stopped moving to investigate it would stop. I suspected the muffler but it seemed firm. Finally the rattle got bad enough that I could see the muffler moving while just idling. I jacked up the back end, removed the wheel and pulled the rubber skirt off and found the two bolts missing from the bottom of the bracket. It appears that Kubota has tried to figure out how best to prevent muffler rattle and as such have come up with at least three ways to secure the muffler over the years. My machine has 1,200 hours and close to 8,000 miles and has the latest muffler bracket style, although the transmission and muffler have the bolt holes for the previous bracket mount that was on the end of the muffler. I think my mid-mount bracket that had the two bolts (M8x1.25x20mm) missing has a fatigue break in the works so I will have to remove it and repair soon. In any case, if you have this type of bracket keep a close eye on the bolts!