601 602 603 Diesel Engine Serpentine Belt Replacement Procedures

Sep 4, 2021


Welcome to Grafco Electric! In this detailed guide, we will walk you through the step-by-step procedures for replacing the serpentine belt on your 601, 602, and 603 diesel engines. Our expert technician, Kent Bergsma, has provided comprehensive instructions to help you maintain and repair your diesel engines with ease.

Why is the Serpentine Belt Important?

The serpentine belt plays a crucial role in the proper functioning of your diesel engine. It drives multiple components such as the alternator, water pump, power steering pump, and air conditioning compressor. A worn or damaged serpentine belt can lead to various mechanical issues and engine failure.

Tools and Materials Needed

  • Socket set
  • Torque wrench
  • Belt tensioner tool
  • New serpentine belt (make sure to choose the correct belt for your specific engine model)

Step-by-Step Serpentine Belt Replacement Procedures

Step 1 - Prepare for the Replacement

Start by ensuring your engine is cool and disconnect the negative terminal of the battery to prevent any electrical accidents during the replacement process. Then gather the necessary tools and materials mentioned above.

Step 2 - Locate the Belt Routing Diagram

Refer to your engine's manual or the belt routing diagram located on your vehicle to identify the correct routing pattern for the serpentine belt.

Step 3 - Release Tension and Remove the Old Belt

Using the belt tensioner tool, rotate the tensioner in the appropriate direction to release tension from the belt. Slide the old belt off the pulleys and carefully remove it from the engine.

Step 4 - Install the New Belt

Referencing the belt routing diagram, carefully thread the new serpentine belt around the pulleys according to the proper path. Ensure the belt is seated correctly on each pulley and aligned with the diagram.

Step 5 - Check Belt Tension

Once the new belt is installed, use the belt tensioner tool to apply appropriate tension. Refer to your engine's specifications or the manual provided by the manufacturer for the proper tension value. Be careful not to overtighten the belt.

Step 6 - Reconnect Battery and Test

Reconnect the negative terminal of the battery, then start your engine to verify that the newly installed serpentine belt operates smoothly without any unusual noises or issues.


Congratulations! You have successfully replaced the serpentine belt on your 601, 602, or 603 diesel engine. Regular maintenance and prompt replacements ensure the longevity and optimal performance of your diesel engine. If you ever require any further assistance or technical guidance, please don't hesitate to contact Grafco Electric. Our team of experts is always ready to help you with your diesel engine needs.

About Grafco Electric

Grafco Electric is a leading provider of high-quality diesel engine maintenance and repair resources. We offer comprehensive guides, downloads, and expert advice to help diesel engine enthusiasts like you keep their engines running smoothly. Whether you are a professional mechanic or a passionate diesel engine owner, Grafco Electric is your trusted source for all things related to diesel engines.

Matt Battersby
This guide is a lifesaver! 💪 I can finally tackle this replacement on my own. Thank you Grafco Electric! 👍
Nov 8, 2023
Norman Frazier
Great step-by-step guide!
Oct 17, 2023