This unit has separate pumps and wheel motors you have to manually take a wrench and open the bypass valves on the pumps to release the hydros for it to roll. Heck of a mower I own four of this style mowers love them. Three of mine are 1999 and 2000 year models, I also own a 2010 model. Got to fix the engine on the 2010 model. Yes the 1999 and 2000 models run and cut grass. Show me other mowers that will still do that with that many years on them. People that own them just won't give them up. Where I use to work people would put $4000.00 in a new engine to keep them going.