• Medium-Duty (DuraStar, MV, 4300/4400 Series): Usually fits engines like the Navistar DT466, DT570, and MaxxForce 7/9/10.

• Heavy-Duty (ProStar, TranStar, LoneStar, LT Series): Fits large-bore engines including the Cummins ISX15, X15, and Navistar N13/A26.

• Work Trucks (WorkStar, HV, 7000 Series): Fits vocational models used for dump trucks or mixers with Navistar or Cummins powerplants.

Technical Specifications to Check:

• Voltage: 12 Volts.

• Tooth Count: Usually 11 or 12 teeth on the drive pinion (this must match your flywheel/ring gear exactly).

• Mounting: SAE #1 or SAE #3 flange (the "nose" of the starter).

• Features: Look for OCP (Over-Crank Protection) to prevent the motor from burning out during long cranking cycles in cold weather.

1. High Torque Output: Since diesel engines have very high compression ratios, these 12V starters are built to provide massive rotational force.

2. Solenoid: The smaller cylinder attached to the top of the motor. It acts as a powerful relay, engaging the pinion gear and completing the electrical circuit to the motor.

3. Over-Crank Protection (OCP): Many genuine International starters include an internal thermostat that cuts power if the motor gets too hot from trying to start a stubborn engine, preventing the starter from burning out.

4. Soft-Start Technology: Some modern versions (like the Delco Remy 39MT often used in Internationals) use technology to engage the gear before it starts spinning, reducing wear and tear on the engine's ring gear.

Common Applications: It is used across the entire International lineup, from the MV/DuraStar medium-duty trucks to the LT/ProStar Class 8 highway tractors.

• The "Single Click" or Rapid Clicking: When you turn the key, you hear one loud "click" or a machine-gun-like clicking sound. This usually means the solenoid is trying to engage, but the motor isn't spinning or there isn't enough voltage.

• Grinding Noise: If you hear a loud metallic grinding sound, the starter's drive gear (pinion) is not meshing correctly with the flywheel. This can eventually strip the teeth off your engine’s ring gear.

• Freewheeling (Whirring Sound): You hear the starter motor spinning (a high-pitched "whirr"), but the engine isn't cranking. This happens when the starter gear fails to pop out and grab the flywheel.

• Slow Cranking ("Labored" Start): The engine turns over very slowly, as if the batteries are dead, even though the batteries are fully charged. This often indicates internal wear or high electrical resistance inside the starter.

• Smoke or Burning Smell: Persistent cranking can overheat the motor. If you see smoke or smell burning insulation, the starter has likely shorted out internally.

• Intermittent Starting: The truck starts fine one time, but does nothing the next, only to work again later. This is often a sign of "dead spots" on the internal armature or worn-out carbon brushes.