Comprehensive 2nd Gen 5.9L Cummins Maintenance Guide & Parts List

If you’re reading this page, it’s probably because you own a 2nd Gen Cummins and you’re looking to learn about keeping your truck in good running order. 

2nd generation Cummins are 1994-2002 Dodge Ram pickup trucks equipped with either the 5.9L 12 valve Cummins engine, or the 5.9L 24 valve Cummins engine.

These trucks were the successors of the widely popular and successful 1st gen Cummins, and they didn’t disappoint. The 2nd gen versions of these trucks were a slightly more sophisticated - but just as reliable - version of the first.

Comprehensive 2nd Gen 5.9L Cummins Maintenance Guide & Parts List

However, the main determiner of reliability in any vehicle is not only the manufacturer and the parts used to build the truck but also YOU and how well you maintain your pick-up. 

 If you’re not familiar with diesel trucks, fear not. That’s exactly why we’ve put together this comprehensive guide, containing all the key information for keeping your truck running optimally. 

We’ll include everything from the correct service intervals to follow, to the recommended filters, fluids, and motor oil and where to buy them. 

PS. Also check out our other guides such as 7 Recommended Jeep Wrangler Wheel and Rim Guide and 5 Recommended Overlanding Tires for Your Travel Adventures Guide.

Maintenance intervals 

Specific maintenance intervals are recommended for a reason, but sadly a lot of people skip these to save a few extra dollars now (though they’ll lose money later on), whereas others simply don’t know what the second generation Cummins maintenance intervals are. 

The reality of the situation is that while you might save money right now by extending maintenance intervals, neglecting the maintenance of your truck is likely to cost you in the long run. 

It’s also common for people to try to cut corners and save money by using cheaply-made aftermarket filters and fluids. While these claim to be a substitute for the OEM products, they’re not the same quality at all, which is why it’s best to stick with recognized brands such as Mopar or Fleetguard. 

Which Variation of the 2nd Gen Cummins Do You Have?

It’s also essential to know the type of engine your 2nd Gen Cummins has.

The 12-valve will have maintenance intervals very similar to the 1st Gen Cummins, and will also use many of the same parts. You’ll find this engine on 1994-1998 2nd Generation Cummins pickups.

The trucks made after mid-1998 have a 24-valve design instead, and these have slightly different service intervals and require different parts. 

How Often Do I Need to Service my 2nd Gen?

Once you know which type of 2nd gen Cummins you have, you can then identify how frequently it needs servicing. 

However, this also depends on what you use your truck for and how frequently you use it. 

For example, if you frequently tow or tow very heavy equipment, this can take a toll on your vehicle,  as can living in a big city, or leaving your Cummins idle for extended periods of time. If any of these factors are relevant to you, you need to follow a severe service schedule. 

If you’re a daily driver, tow heavy infrequently, or tow light loads, you can follow the normal operating conditions service schedule. 

While not every aspect of your 2nd Gen Cummins needs checking every time you service it, there are certain components that need checking every time, including: 

  • Inspecting all steering and suspension components for wear
  • Thoroughly inspecting the exhaust system
  • Checking all components holding oil or fluid for leaks.
  • Checking your driveway or usual parking spot for signs of any leaks 
  • Inspecting the brake hoses
  • Rotating your tires
  • Checking all fluid levels
  • Checking your tires for nails, screws, bulges, or other forms of damage.
  • Drain water from fuel filter (this should be done monthly)

Final Verdict 

Keeping your 2nd gen Cummings in optimal condition by regularly servicing your vehicle will ensure you get the most out of your truck, and will also see it last a whole lot longer than if you neglect it. 

While it can be tempting to cut corners now, the main thing to remember is that this will cost you in the long-run, as you’ll simply end up paying more later down the line. 

The same goes for filters and fluids - the key thing here is to use official products, not cheaper brands that could save you a few cents but cause you long-term damage later on.