Explain the use of shims in wave spring assemblies for tolerance compensation.

In complex mechanical assemblies, the 'working cavity' height for a wave spring often has a large tolerance due to the stack-up of multiple machined parts. Since the load $P$ of a wave spring is highly sensitive to the working height ($P = k imes (L_0 - L_{work})$), shims are used to calibrate the preload. Variable thickness shims or a set of standard $0.005$ inch shims allow technicians to adjust the cavity height until the measured load meets the specification. This is particularly common in high-performance clutch packs and heavy-duty drivetrain components where precise engagement pressure is mandatory.