Left-hand and right-hand are referenced from the point of view of the tractor operator.
The flat backside of the belt rides on flat idlers; the inside vee rides in v-idlers and pulleys.
LX models use belt part number M146667 which is 87.64" long, 0.5" wide, HA section 0.31 thick 32 deg. PREM
GT models use belt part number M127523 which is 89.8" long, 0.66" wide, HB section 0.41 thick 32 deg. PREM
Similar Models: John Deere LX255, LX277, LX279, LX288, GT225, GT235, GT245, GT255
Overall view of the drive belt layout (#1). The engine pulley is off to the right and the transmission pulley is to the left.
Disconnect the drag link from the steering arm (#2, yellow) and disconnect the wiring (#2, blue) to the electric clutch. Bring the belt above the brake shaft, around the steering shaft (#2, white) and forward around the upper engine pulley.
Loop the back end of the belt around the transmission pulley (#3).
Unhook the tensioning spring from the idler arm (#4, white).
Loosen both idler pulleys, route the belt around the idlers, making sure the belt is within the belt guides (#5, blue).
Deere LX266 42C deck belts (#6). Discharge side is on the left of the photo.
Deere 48C and 54C deck belts diagram (#7). Discharge side is on the right of the photo.