I've never disassembled one of these, so I don't fully understand all the details of the design, but it is clear from the descriptions in M20-282-A that the spring serves primarily as a brake to keep the gear in the up position. This is necessary because the actuator uses a ball screw (recirculating ball bearings between the nut and threaded jackscrew), likely to reduce friction under load, and ball screws can back drive the actuator. The Mooney landing gear has no up locks, so the weight of the