Where would you find the dimensional tolerances for the wrist pin fit in an aircraft engine?

• A. In the airframe maintenance manual.
• B. In the illustrated parts catalog.
• C. In the overhaul manual for that engine.
• D. In the weight and balance manual.

Answer: (C)

Dimensional tolerances for a wrist pin fit are found in the engine’s overhaul manual because it specifies the exact limits for assembling and reconditioning engine components. The wrist pin must have the correct clearance with the piston and connecting rod bore, and the overhaul manual provides the precise pin diameter tolerances, bore sizes, and the proper measurement methods, along with steps to take if wear exceeds limits. The airframe maintenance manual covers external airframe systems and structures, not internal engine fits. The illustrated parts catalog lists parts and part numbers but not detailed tolerances, and the weight and balance manual deals with mass distribution, not component fits.