Never seen a 540 with a 4wd. The 540 didn't have Hydro, which makes kinda hard to put 4wd on. Years ago there was a 4wd kit for the 4400 deer (similar sized machine and no Hydro). I guess they worked, but were kind of a pain to keep adjusted. If you want one on your 540. . You may be able to find one in a salvage yard some where, and adapt it to your machine. Have Fun Joe
