Control of spring assembly preload of a friction element for an automatic transmission

摘要

A friction element subassembly for an automatic transmission includes a hydraulic cylinder fixed to a hub, the hub providing a snap ring groove, and a balance piston surrounding the hub defining a space within. A return ring assembly, located in a piston, applies a force to the center of a ring through a load cell. The position of one end of a length gauge is set at a predetermined distance from a reference position, the gauge extending through a guide bushing and ring to a snap ring groove. When a predetermined force of a predetermined magnitude is applied to the ring, a preferred thickness of the snap ring is determined from a dimensional change readily accessible from the assembly. A snap ring having substantially the same thickness as the preferred thickness is inserted in the snap ring groove to produce a predetermined compression preload in the spring assembly.