14 has rods 42a c plates 13 15 and 16 have rods not shown extending into corresponding holes however these rods do not have the springs nor grooves associated with them the set screw slot end of pin 72c is shown and is representative of the corresponding pins 72b and 72a not shown set screws 72d f and 74a f are used to hold the rods from plates 13 15 and 16 if desired the plates may be modified to include rubber surfaces abutting the cylinder rod to minimize the chance of damage to the polished surface of the rod as an example of use the support leg 58 of heavy mobile equipment 50 is extended to lift wheel 56 substantially above the ground with the wheel 56 off of the gound the propelling means of the mobile equipment is rendered inoperable the extended shaft 59a of hydraulic cylinder 59 is placed in a weight supporting position bearing a portion of the weight of the equipment anti theft device 10 in an uncompressed state is mounted about shaft 59a and the anti theft locking mechanism 45 is operated with a key not shown to latch mechanism 45 in a closed position the hydraulic cylinder 59 is then released to compress against the anti theft device 10 this not only conceals the anti theft locking mechanism 45 beneath a load bearing surface of the strut but also maintains the support leg 58 in a load bearing condition in view of the length of the anti theft device 10 while the invention is described in connection with the extension of a strut of mobile equipment it is equally applicable to the extension of any other member of a piece of mobile equipment which.