Detroit Diesel — Alternator Disassembly
Repair & overhaul
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Accidental starting. Can cause severe injury or death. Disconnect the battery cables before working on the generator set.
- Hot engine and exhaust system. Can cause severe injury or death.
- Explosive fuel vapors. Can cause severe injury or death.
Procedure
- Disconnect and remove starting batteries and AC-powered accessories; shut off fuel and drain as needed.
- Disconnect fuel, cooling, exhaust, and output leads; remove junction box panels.
- Disconnect controller-to-engine and engine-to-alternator harnesses; remove junction box and controller.
- Remove fan guard, rotating rectifier housing, alternator (rodent) guard, and speed sensor.
- Remove leads from three AC terminals and F+/F-- terminals on RRA hub; remove diode assembly plates.
- Remove two mounting screws; lift off RRA hub and magnetic actuator.
- Remove alternator vibromount bolts; hoist alternator end off vibromounts.
- Support engine with wood blocks; remove adapter-to-flywheel housing bolts and drive disc hardware.
- Separate alternator from engine; set alternator horizontally.
- Hoist rotor assembly vertically; remove drive discs and fan.
- Hoist rotor by lifting eye; lower to horizontal on a pallet.
- Remove bearing with hydraulic press if needed.
- Remove adapter and end bracket from stator by tapping with rubber mallet.
- Remove the exciter field winding from the end bracket.
Tools required
- Hoist Amazon
- Lifting eyes Amazon
- Wood blocks Amazon
- Rubber mallet Amazon
- Hydraulic press Amazon
- Stud remover Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.