I ordered 2 ZTR Transaxles (Right and Left) I could have installed them myself since i had already pulled the old ones to check and replace oil etc, but that did not solve the problem. So I ordered 2 new ones and had a local shop install them that way they could do the rest of the tune up and make all the proper adjustments. I saved over $800 on parts! The original quote from another shop was $3,100 for a complete job: $1600 for Drives plus $800 in labor plus all the other stuff they thought they should fix. I have a 2013 Husqvarna Z5424 with about 550 hours. Brand new it only cost about $2,500. (That first shop just wanted to sell me a new machine. The 2 new drives work Great! Under $800 total for 2 new drives and labor was $300. Parts were perfect and if the machine didn't need so much other work I may have installed them myself. (I should note that i was given this machine at the end of last season so I didn't have up front cost.)