4L60E GM Genuine Pump Rotor Kit, 18mm Select Fit 24219542

GM part number 24219542 is the factory pump rotor kit for the GM 4L60E front pump, and it also serves the 4L65E built on the same pump design. This is the 18mm select-fit rotor. GM sells the 4L60E rotor in several select-fit thicknesses (17.9675mm, 17.9805mm, 17.9935mm and 18mm) so the rotor-to-pocket clearance can be set correctly during a pump rebuild.

The pump rotor, vanes and slide wear together. Debris from a burnt clutch pack or a failed converter scores the rotor faces and the pump pocket, and the result is low line pressure, slipping on the 3-4 shift, a whine that follows engine speed, and a pump that loses prime after sitting. If the pocket and slide still measure good, replacing the rotor assembly restores pump output without buying a complete pump.

On the bench: pull the pump, separate the halves, and measure pocket depth against the old rotor to choose the correct select-fit size before ordering. Check the slide and pocket for scoring, clean everything, install the new rotor and vanes, then torque the pump halves together with the pump sitting in an alignment band so the bushing stays centered. Buyers have noted the vane rings are not included in this kit, so order a pair separately if yours are worn.