A mobile car crusher (1) has two hydraulic cylinders (13, 20) with one at each end of a heavyduty trailer. A cylinder base (14) on a bottom of each of the two hydraulic cylinders is positional hydraulically proximate a bottom of each of two cylinderguide posts (7, 9) for travel mode and proximate a top of each of the two cylinderguide posts for carcrusher operating mode.