a vehicle equipped with an automatic transmission (including semi automatic) is difficult to push start since selection of transmission gears is possible only when the internals of such a gearbox are rotating. however, automatics with both front and rear hydraulic pumps can be push-started with no problems. the last american automobile with this type of transmission was the 1969 chevrolet corvair with a powerglide automatic. while push-start can cause more damage to a hydrolocked engine, the starter motor is limited.