Hi, my name is Gil from Sherman, TX and I have 5 zero turns whose 2 are not running correctly. Of course these are 2009 model Swisher ZT2760B and ZT2766KP. Swisher made the worst hydro transaxles I have ever seen. They all went out on both mowers, so I decided to replace them with Hydro Gear ZT-3100 hydros. Well, needless to say it took me over 6 months to do the conversions due to fabricating custom brackets to accommodate the larger transaxles. They run but not as fast as they advertise, Guess it might be because I replaced the smaller drive pulley with a larger one to match the hydro pulleys. Mistake since they seem to turn faster than normal. I will try to correct the problems within the next 6 months and post later to try and get some suggestions from the forum.