How to Replace a Harley Davidson Alternator

by Kyle McBride

Harley Davidson alternators produce three-phase alternating-current (AC) electricity. This electricity is rectified to direct current (D/C) power at the voltage regulator, supplying the motorcycle's battery and D/C system components. Replacing the alternator can be accomplished with basic mechanic's tools.

Replacing the Alternator

Remove the drain plug located under the clutch area of the primary chaincase and drain the chaincase lubricant into a catch pan. Remove all mounting bolts from the primary cover and slide the cover from its locating studs. Loosen the primary chain tensioner and inspect it for wear (this is a logical time to replace the tensioner shoe, since you are in the case).

Lock the primary chain where it enters the bottom of the clutch drum. Remove the engine sprocket nut and slide the compensator/sprocket assembly from the engine sprocket shaft. Slide the reluctor bowl off the engine sprocket shaft. Push the stator plug through the hole into the inner primary case. Remove the stator mounting bolts and slide the stator from its support boss. Remove the stator from the case.

Slide the new stator onto the support boss and orient it so that the stator wires are closest to the stator plug hole in the case. Install and torque the new stator bolts to factory specification (refer to manufacturer's torque sheet). Do not re-use the old bolts. The bolts come pre-treated with Loctite and are designed for one-time use. Insert the stator plug into the plug hole and snap it into place.

Slide the reluctor bowl onto the sprocket shaft and bottom it onto the shaft shoulder. Align the splines on the shaft and the compensator/sprocket assembly and slide the assembly into position. Install the engine sprocket nut and torque to factory specification for your model of Harley. Adjust the primary chain tensioner to factory specification.

Scrape the old primary gasket from the case. Harley Davidson gaskets are produced with a print-o-seal feature that melts and '"cooks" onto the case surface. Insure that all of the old gasket is removed from the machined surfaces. Use caution when scraping the gasket, as the cast-aluminum cases are easily gouged, leading to poor sealing and leaks. Install the fresh gasket onto the locating studs, followed by the primary chaincase cover. Torque the primary cover to the proper torque and in the recommended pattern according to the specification sheet for your model of Harley. Remove the inspection plate and add new chaincase lubricant. Replace the inspection cover gasket and re-install the inspection plate.

Warnings

  • close The engine sprocket shaft nut is under very high torque, around 100 to 120 foot-pounds. Impact tools are acceptable for disassembly but not for reassembly. Follow proper torquing procedures with an accurate torque wrench during re-installation.
  • close Inspect all inner primary case bolts and keepers while the case is open. Broken keepers or loose bolts can back out of their holes and cause a catastrophic lockup at the clutch, resulting in loss of control of the vehicle.

Items you will need