Pinion Cap

The pinion cap is a protective and structural component used in the power end of mud pumps. It covers and secures the pinion shaft and bearing assembly, keeping lubrication oil in and contaminants out. Its primary functions include protecting internal gears, maintaining alignment, and supporting efficient power transmission from the motor to the crankshaft.

Constructed from high-strength cast iron or steel, pinion caps are designed to withstand intense mechanical stress, vibration, and thermal expansion. A precisely machined cap helps ensure proper gear meshing and reduces the risk of oil leakage or bearing misalignment, both of which are critical for long-term pump reliability.

Our pinion caps are fully compatible with FMC BEAN, ATLAS COPCO (Trido series), and TRIAQUA mud pumps. They meet OEM specifications for fit and durability, making them ideal for rebuilds, overhauls, or as replacement parts during routine service.