Hydraulic pump flange 903/20774 JCB, aftermarket

For the JCB machines: hydraulic pump flange 903/20774, an aftermarket part. According to the product card, this flange is used in the hydraulic pump drive.

The flange is chosen by spline count and diameter, bolt circle and propshaft connection type. Several numbers on the card for one part are its versions over the years. When the flange is changed, the shaft seal is renewed too and the nut or locking element is replaced with a new one. Correct seating of the flange and tightening of the nut also set the preload of the pinion or output shaft bearings, so the job should not be rushed.

Specifications

Compatibility

According to the product card, 903/20774 is a flange. Fit is confirmed by the part number. The catalogue also has the genuine version of this part. Other parts are in Transmission.

Fitting

Remove the flange with a puller after disconnecting the propshaft and undoing the nut. After renewing the seal, fit the new flange with the splines and seal surface lightly oiled, tighten the nut to the manual torque or bearing preload and lock it. Tighten the propshaft bolts to the specified torque and check for leaks after the first run. Marking the flange position on the shaft before undoing the nut makes reassembly easier on propshafts that need balance. The nut is usually a locking type and is not reused.