At Dovinta Heavy Truck & Equipment Service, we recently completed a starter repair and overhaul on a Western Star 4900 powered by a Detroit Diesel 60 Series engine.
Symptoms Reported
The truck was experiencing a slow turn of the engine during startup. In colder weather, the issue became worse, requiring longer cranking and causing unnecessary strain on the batteries and electrical system.
Diagnosis
After removing and opening the starter, our inspection revealed the main causes:
Burned and dirty rotor contacts, covered in carbon buildup.
Worn solenoid contacts, with visible pitting that restricted proper current flow.
Both issues prevented the starter from delivering full power to the Detroit Diesel engine.
The Overhaul Process
Our heavy truck service team carried out a complete starter rebuild, including:
Rotor resurfacing on the lathe to restore smooth, conductive contact surfaces.
Solenoid contact service and replacement, ensuring reliable current delivery.
Detailed inspection of windings, insulators, and wiring.
Professional reassembly with correct torque and alignment.
(See photos of the rotor before and after machining.)
Results
Once reinstalled, the Western Star’s engine cranked faster and stronger, with a rigid and confident startup every time. The driver immediately noticed improved performance and reliability.
Why Choose Dovinta?
We specialize in heavy-duty truck electrical repair, starter and alternator rebuilds, and Detroit Diesel service. Whether it’s a Western Star, Freightliner, Kenworth, or Peterbilt, our team has the expertise and equipment to keep your fleet moving.
If your truck is showing slow cranking, weak starts, or electrical issues, contact Dovinta today for professional heavy truck starter repair.
