Transmission oil pump 121-7385 CAT, OEM

Transmission oil pump 121-7385 is an OEM part for the Caterpillar backhoe loaders.

The transmission oil pump supplies pressurised oil to the clutch packs, torque converter and lubrication circuit of a powershift or powershuttle transmission. It is driven from the engine through the torque converter and draws oil from the transmission sump through a strainer. A worn pump gives low clutch pressure: the gearbox works normally when cold but slips when hot, the machine loses traction on slopes and the oil overheats.

Specifications

Compatibility

According to sources, 121-7385 is the transmission pump of Caterpillar 414E, 416C-416F, 420D-420F, 422E-422F, 424B-424D, 426C-432F, 434E-446D and 450E-450F backhoe loaders. Other parts are in Carraro.

Fitting

Before replacing the pump, check the transmission oil and strainer, and if there is metal in the oil inspect the internal gearbox parts too. Fit the new pump with a new gasket, aligning the drive splines, and tighten the bolts to the specified torque. Renew the transmission oil and filter, then measure the clutch pressures. On first start, check with the gauge or a pressure gauge that the pump picks up oil and builds pressure.