Cummins starter motor

Types of Cummins starter motor

A Cummins starter motor is an electric motor used to crank large diesel engines, mostly in trucks. The starter motor is an essential part of the starter system. It gets power from the starter battery through the starter switch. When the starter switch sends a signal, the starter solenoid acts like a switch. It closes a circuit and sends current to the starter motor. The starter motor then draws enough current to turn over the engine so that it can start running.

There are two main types of Cummins engine starter motors:

• Gear Reduction Starter Motors: Gear reduction starter motors are the most common starters for Cummins engines. They are smaller and use less current than other types of starter motors. Gear reduction starters use a set of gears to increase the torque at the pinion gear. This means the motor spins the gears faster, pushing the pinion gear and drawing in teeth more quickly. As a result, the gear reduction starter provides more power to crank the engine without using more current. This makes the gear reduction starter ideal for applications with a smaller 12-volt battery. The Cummins ISB starter motor is a typical example of a gear reduction starter motor.
• High-Torque Starter Motors: High-torque starter motors are often used for applications that involve heavy loads or high-compression engines. These starter motors provide a lot of cranking power to turn over the engine. High-torque starter motors are larger and draw more current than their counterparts. As a result, they are mostly used in trucks, buses, and other commercial vehicles.

Specifications and Maintenance of Cummins Starter Motor

While the specifications of the Cummins starter motor may differ, depending on the type and model, the following are general specifications:

• Voltage

  Starter motors work with different voltages, such as 12-volt and 24-volt starter motors. The 12-volt motors are the most common. They are used in light-duty vehicles and smaller engines. The 24-volt motors are used in heavy-duty trucks and vehicles with bigger and more powerful engines.

• Power

  The power of the starter motor is given in kilowatts (kW) or horsepower (hp). The power varies, depending on the size and model of the motor. Smaller motors have a power rating of around 1.0 kW (1.3 hp). On the other hand, larger motors have a power rating of about 4.0 kW (5.4 hp).

• Torque

  Torque is the twisting force the motor generates to turn the engine's crankshaft. The torque is measured in Newton meters (Nm) or pound-feet (lb-ft). The torque rating of the Cummins starter motor also varies, depending on the size and model. The smaller motors have a peak torque of about 10 Nm (7 lb-ft), while the larger motors generate a peak torque of up to 50 Nm (37 lb-ft).

• Speed

  The speed of the starter motor is given in revolutions per minute (RPM). The speed also depends on the model and size of the motor. Smaller motors have a no-load speed of about 10,000 RPM, while larger motors can have a speed of up to 20,000 RPM.

• Size and Weight

  The size and weight of the starter motor also vary depending on the model and size of the motor. Generally, the length ranges from 200 mm to 400 mm. The width also ranges from 100 mm to 200 mm. In terms of weight, the starter motor can weigh anywhere from 1 kg to 5 kg.

Below are some general tips for maintaining the Cummins starter motor:

• 1. The battery should be checked regularly to ensure it is in good condition. This is because a weak battery puts a lot of strain on the starter motor.
• 2. To avoid overheating, the starter motor should not be engaged for a long time.
• 3. The starter motor should be used only when the engine is turned off.
• 4. The electrical connections of the starter motor should be checked regularly to ensure they are clean and tight.
• 5. The starter motor should be kept clean and free of debris.
• 6. The Cummins starter motor should be lubricated regularly.

How to Choose Cummins Starter Motor

To choose the right Cummins starter motor for a specific engine, consider the following factors:

• Voltage: As mentioned earlier, the 12V starters are used in lighter vehicles and trucks, while the 24V starters are used in larger diesel engines. Choose the voltage that matches the engine's electrical system.
• Engine Size: Larger engines, such as those found in heavy-duty trucks, require more powerful starter motors to crank the engine. The starter motor's power rating is usually expressed in torque or wattage. Select a starter motor compatible with the engine's size and type.
• Compatibility: Ensure that the chosen starter motor is compatible with the Cummins engine model and version. Check mounting options, flywheel size, and other connection details to ensure a proper fit.
• Quality: Choose a starter motor from reputable manufacturers that meet industry standards. A high-quality starter motor ensures reliability and durability, reducing the need for frequent replacement.
• Budget: Consider the cost of the starter motor and its components. While it may be tempting to go for the cheapest option, balancing quality and affordability is essential.

How to DIY and Replace Cummins Starter Motor

Replacing a starter motor can be a DIY-friendly task. Here is how to do it:

Tools needed:

• Socket wrench set
• Extension and universal joint
• Torx bit set
• Jack and jack stands
• Lug nut key
• New starter motor
• Battery terminal cleaner
• Safety glasses
• Gloves

Steps:

• Disconnect the battery terminals (negative first) to avoid short circuits.
• Lift the vehicle with a jack and jack stand.
• Remove the wheels using a lug nut key.
• Get underneath the vehicle and locate the starter motor.
• Use a socket with an extension and universal joint to remove the bolts holding the starter motor.
• Remove the old starter motor and replace it with a new one.
• Reconnect the battery terminals and start the vehicle.

Q and A

Q1: How can one tell if a Cummins starter motor is bad?

A1: There are several signs that point to a damaged starter motor. They include: the engine not starting or taking longer to start, strange noises when starting up the engine, and weak or no cranking.

Q2: What makes a Cummins starter motor go bad?

A2: A starter motor can go bad due to several reasons. One of them is a faulty battery, wiring, or corrosion. Other issues include wear and tear, moisture damage, and improper usage.

Q3: Can a Cummins starter motor be rebuilt?

A3: Yes, it can. However, it is important to consider the cost of rebuilding the motor versus buying a new one. Rebuilding can be tedious and complicated.