拖拉机换“心脏”必须办手续发动机是拖拉机的“心脏”，发动机的号码在驾驶员的行驶证上有详细的记载。如果换了发动机，却没有办理更换手续，拖拉机上了公路被扣车或是年检过不了关就难免了。变更手续要到县农机监理机关去办理。办手续时要带好乡镇农机监理员签发的“拖... Tractor for “heart” must be completed The engine is the “heart” of the tractor, the engine number in the driver’s license have a detailed record. If you change the engine, but did not apply for replacement procedures, tractors on the road was seized cars or annual inspection can not pass off is inevitable. Change procedures to the county agricultural supervision agencies to handle. Do the formalities to bring the township farm machinery supervisor issued a "drag ...