Our M1008 should have already had a locker in the rear axle from the factory. Of course, our oddball CUCV did not. We quickly remedied that situation by calling West Coast Differentials to order an Eaton Detroit Locker (PN 225S10). The 14-bolt rear axle in our truck is perhaps the easiest axle to install a Detroit Locker in. The locker simply replaces the differential gears and fits into the factory case. The only gear setup needed is adjusting the backlash during reassembly.