relieving and reducing the compressive load on clutch pack 56 this allows for de compression of clutch pack 56 as piston 64 retracts the loading is gradually removed from the open frame of pins 55 and the book end clutch plates or caging washers 54 b and 54 c allowing spring washer 58 to re compress clutch pack 56 against thrust plate or shoulder washer 57 compression of clutch pack 56 is enabled because ends 55 a of pins pass through corresponding holes 57 a in thrust plate or shoulder washer 57 as piston 64 retracts towards base 44 decompression of the clutch pack 56 which is otherwise normally clamped between spring washer 58 and shoulder washer 57 is sufficient to allow selectively limited or progressive slippage or unlimited slippage between clutch plates 54 and friction washers 52 as clutch pack 56 is decompressed the individual clutch plates 54 are free to translate slightly along posts 48 and pins 55 and friction washers 52 are free to translate slightly along the external splines of spool 50 so as to slightly expand clutch pack 56 they translate so as to re compress within clutch pack 56 and lock the axle assembly 30 as the spring washer 58 is allowed to re engage against the clutch pack 56 pressing clutch pack 56 against shoulder washer 57 as the actuator piston 60 is retracted and pins 55 retract through holes 57 a a diagrammatic partially cutaway view of such an arrangement is shown in the sectional view of fig4.