Dodge 5.9 Cummins Engine Diagram

How to maintain your 2nd Generation Dodge Cummins Diesel Truck

If you're reading this, you're probably the proud owner of a 2nd Gen Cummins. The term second generation Cummins refers to 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 had big shoes to fill because of how successful and durable the first generation Cummins was. Thankfully, despite becoming slightly more sophisticated, these trucks are also very reliable. Much of your truck's reliability, however, is dependent on you being an expert on 2nd Gen Cummins Maintenance. If you're not familiar with diesel trucks or a diesel mechanic, this can be a difficult task.

There's no need to worry. This post is our comprehensive guide to 2nd Gen Cummins maintenance and it'll give you everything you need to take care of your truck. We go over the correct service intervals to follow depending on how you use your truck. We will also make recommendations on the best filters, fluids, and motor oil to use and we even link to where you can buy them on Amazon! You'll also learn how much of each fluid or oil is required, so you can purchase the right amount.

2nd Gen 5.9L Cummins Maintenance Guide — 2nd Generation 5.9L Cummins

Don't be a cheap/lazy A**

People often fall short because they don't know what the proper second generation Cummins maintenance intervals are. Sometimes people know the intervals but they just want to extend them a little bit to save some dollars now. Just remember, neglecting your truck can lead to major, unnecessary repairs down the road. Another common shortfall is using cheaply made aftermarket filters and fluids. DON'T USE AFTERMARKET FILTERS OR FLUIDS. They're not nearly the same quality as the OEM products they substitute for. Stick with Mopar or Fleetguard. Spend the money now to save yourself in the future. Now go out there and give ol' Bessy the servicing she's been needing.

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

Before we go any further, it's important to know exactly what Cummins engine your truck has. Its important to know if you have a 12 valve or a 24 valve engine. The 12 valve will have very similar maintenance intervals and use many of the same parts as the first gen Cummins. This engine is found on 1994-1998 2nd Generation Cummins pickups. Beginning with 1998.5 model years trucks, a 24 valve design is used. You will have slightly different service intervals and need different parts for 1998.5-2002 trucks. If you want to know more about the differences between the two designs, visit our 2nd Gen Cummins specifications resource. Now that we've got this figured out, let's take a look at how often you need to service your truck.

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

How often should you service your truck depends on how you operate it. Do you tow heavy? Do you tow frequently? Do you live in a big city, or idle for extended periods of time? If you answered yes, you need to follow a severe service schedule. If you use your truck as a daily driver, tow heavy infrequently, or only tow light loads, the normal operating conditions service schedule is what you should follow. Not every component of your 2nd Gen Cummins needs maintenance every mileage milestone. There are some things you'll want to do every time you service your truck though. Check out the bullet points below.

9 Things You Should do Every Time You Perform Service

Inspect all steering and suspension components for wear
Thoroughly inspect exhaust system
Check all components holding oil or fluid for leaks.
Check your driveway or wherever your truck is normally parked for signs of any leaks
Inspect Brake hoses
Rotate your tires
Check all fluid levels
Check your tires for nails, screws, bulges, or other damage.
Drain water from fuel filter**** MONTHLY

12V 5.9L Cummins Service Intervals

Follow these service schedules if you have a 1994-1998 12 valve 2nd Generation Cummins.

Normal Operating Conditions

Maintenance/Service	Miles	Kilometers	Months
Change Oil	6,000 miles	9,600 km	6 mo.
Change Oil Filter	6,000 miles	9,600 km	6 mo.
Replace Fuel Filter	12,000 miles	19,200 km	12 mo.
Replace Engine Air Filter	Check Every Service interval, replace as necessary.	See Left	See Left
Flush Cooling System (Initial flush)	36,000 miles	57,600 km	36 mo.
Flush Cooling System (After Initial flush)	30,000 miles	48,000 km	24 mo.
Drain & Re-Fill Automatic Transmission Fluid	24,000 miles	38,400 km	24 mo.
Replace automatic transmission Filter(s)	24,000 miles	38,400 km	24 mo.
Adjust Automatic Transmission Band	24,000 miles	38,400 km	24 mo.
Flush & Re-fill Manual Transmission Fluid	60,000 miles	96,000 km	36 mo.
Replace Transfer Case Fluid	36,000 miles	57,600 km	36 mo.
Adjust Valve Lash	24,000 miles	38,400 km	24 mo.
Replace Rear Differential Fluid	Not Specified by FCA, at least once every 100,000 miles or 5 years	See Left	See Left
Replace Front Differential Fluid	Not Specified by FCA, at least once every 100,000 miles or 5 years	See Left	See Left

Severe Operating Conditions

Maintenance/Service	Miles	Kilometers	Months
Change Oil	3,000 miles	4,800 km	3 mo.
Change Oil Filter	3,000 miles	4,800 km	3 mo.
Replace Fuel Filter	12,000 miles	19,200 km	12 mo.
Replace Engine Air Filter	Check Every Service interval, replace as necessary.	See Left	See Left
Flush Cooling System (Initial flush)	36,000 miles	57,600 km	36 mo.
Flush Cooling System (After Initial flush)	30,000 miles	48,000 km	24 mo.
Drain & Re-Fill Automatic Transmission Fluid	12,000 miles	19,200 km	12 mo.
Replace automatic transmission Filter(s)	12,000 miles	19,200 km	12 mo.
Adjust Automatic Transmission Band	12,000 miles	19,200 km	12 mo.
Flush & Re-fill Manual Transmission Fluid	60,000 miles	96,000 km	36 mo.
Replace Transfer Case Fluid	36,000 miles	57,600 km	36 mo.
Adjust Valve Lash	24,000 miles	38,400 km	24 mo.
Replace Rear Differential Fluid	12,000 miles	19,200 km	12 mo.
Replace Front Differential Fluid	12,000 miles	19,200 km	12 mo.

24V 5.9L Cummins Service Intervals

Follow these service schedules if you have a 1998.5-2002 24 valve 2nd Generation Cummins.

Normal Operating Conditions

Maintenance/Service	Miles	Kilometers	Months
Change Oil	7,500 miles	12,000 km	6 mo.
Change Oil Filter	7,500 miles	12,000 km	6 mo.
Replace Fuel Filter	15,000 miles	24,000 km	12 mo.
Replace Engine Air Filter	Check Every Service interval, replace as necessary.	See Left	See Left
Flush Cooling System (Initial flush)	30,000 miles	48,000 km	24 mo.
Drain & Re-Fill 47RE Automatic Transmission Fluid	30,000 miles	48,000 km	24 mo.
Replace automatic transmission Filter(s)	30,000 miles	48,000 km	24 mo.
Adjust Automatic Transmission Band	30,000 miles	48,000 km	24 mo.
Flush & Re-fill Manual Transmission Fluid	60,000 miles	96,000 km	36 mo.
Replace Transfer Case Fluid	90,000 miles	144,00 km	72 mo.
Replace Rear Differential Fluid	Not Specified by FCA, at least once every 100,000 miles or 5 years****	See Left	See Left
Replace Front Differential Fluid	Not Specified by FCA, at least once every 100,000 miles or 5 years****	See Left	See Left
Adjust Valve Lash	150,000 miles	241,000 km	N/A

Severe Operating Conditions

Maintenance/Service	Miles	Kilometers
Change Oil	3,750 miles	6,000 km
Change Oil Filter	3,750 miles	6,000 km
Replace Fuel Filter	15,000 miles	24,000 km
Replace Engine Air Filter	Check Every Service interval, replace as necessary.	See Left
Flush Cooling System (Initial flush)	30,000 miles	48,000 km
Drain & Re-Fill 47RE Automatic Transmission Fluid	15,000 miles	24,000 km
Replace automatic transmission Filter(s)	15,000 miles	24,000 km
Adjust Automatic Transmission Band	15,000 miles	24,000 km
Flush & Re-fill Manual Transmission Fluid	60,000 miles	96,000 km
Replace Transfer Case Fluid	60-90,000 miles	144-192,000 km
Replace Rear Differential Fluid***	15,000 miles	24,000 km
Replace Front Differential Fluid***	15,000 miles	24,000 km
Adjust Valve Lash	150,000 miles	241,000 km

**** If Front or Rear Axle submerged in water, fluid should be changed as soon as possible.

2nd Gen 5.9L Cummins Fluid Capacity

Oil/Fluid	Capacity – Quarts	Capacity – Liters
Engine Oil /w Filter	12 Quarts	11.4 Liters
Auto Transmission Fluid 47 RE/RH	See Below 4 Quarts Service Refill 14.5-16.5 Quarts dry refill	See Below 3.8 Liters 8.2-15.6 Liters
Manual Transmission Fluid NV4500 NV5600	See Below 4 Quarts 4.75 Quarts	See Below 3.8 Liters 4.5 Liters
Transfer Case NP205 NP231 NP231HD NP241 NP241HD	See Below 2.22 Quarts 1.25 Quarts 1.25 Quarts 2.4 Quarts 3.25 Quarts	See Below 2.1 Liters 1.2 Liters 1.2 Liters 2.2 Liters 3.1 Liters
Coolant	24-26 Quarts	22.7-24.5 Liters
Front Differential Fluid Dana 60	See Below 3.15 Quarts	See Below 3 Liters
Rear Differential Fluid 2WD Dana 70 4WD Dana 70 2WD Dana 80 4WD Dana 80	See Below 3.5 Quarts 3.9 Quarts 3.4 Quarts 5 Quarts	See Below 3.3 Liters 3.6 Liters 3.2 Liters 4.8 Liters

2nd Gen Cummins Maintenance Parts – Fluids, Oil, Filters & More

The following chart is a collection of the parts you will need for 2nd Gen 5.9L Cummins Maintenance. When it comes to filters, you're going to want to stick with Fleetguard or Mopar products. Aftermarket filters don't offer the same filtration characteristics and because of their lesser quality, they can lead to premature part failures. You should also use Mopar fluids exclusively, except for engine oil. There are some really great 15W-40 Diesel engine oils for the 12V and 24V 5.9L Cummins engines. Shell Rotella products are excellent and i've used them in several of my Cummins-equipped Dodge Ram trucks.

Second Gen Cummins Maintenance Parts List

Part Type	Part #	Amazon Link
Engine Oil	15W40	Shell Rotella T4 15W40 Shell Rotella T5 (blend ) 15W40 Shell Rotella T6 15W40
Engine Oil Filter	LF16035 LF3972	Fleetguard Stratopore LF16035 Fleetguard LF3972
Fuel Filter '94-'96 '97-'99 '00-'02	See Below FS1253 FS19598 FS19855	See Below Fleetguard FS1253 Fleetguard FS19598 Fleetguard FS19855
Engine Air Filter	25441 4189	(original) Fleetguard AF-25441 (superseded) Fleetguard AF-4189
Coolant '94-'98 12V '98.4-'02 24V	N/A N/A Mopar 68048953AB	See Below – 50/50 Mixture of Distilled Water & glycol ethylene coolant – 50/50 Mixture of Mopar Antifreeze & Distilled Water
Automatic Transmission Fluid for 47RE/RH	ATF+4	Mopar ATF+4
Transmission Filters '94-'97 '98-'02	See Below 3515996 52118789	See Below Mopar 3515996 Mopar 52118789
Manual Transmission Fluid NV4500HD (5-Speed) NV5600 (6-Speed)	See Options Below – SAE 75W-90 – Mopar MTF	See Options Below SAE 75W-90 Mopar Manual Trans. Fluid
Serpentine Belts '94-'02 '94-'02 /w AC '94-'02 No AC	See Below 53040171AD K080810HD K080653	See Below Mopar 53040171AD Gates K080810HD Gates K080653
Upper Radiator Hose '94-'98 '98.5-'02	See Below 22081 22645	See Below Gates 22081 Gates 22645
Lower Radiator Hose	22082	Gates 22082
Transfer Case Fluid	ATF4+	Mopar ATF+4
Front differential fluid Dana 60 9.25″ AAM	See Below SAE 75W-140 SAE 75W-90	See Below SAE 75W-140 Synthetic Gear Oil SAE 75W-90
Rear Differential Fluid Dana 70 Dana 80 10.5″ AAM 11.5″ AAM	See Below SAE 75W-140 SAE 75W-140 See Right See Right	See Below SAE 75W-140 Synthetic Gear Oil SAE 75W-140 Synthetic Gear Oil SAE 75W-90 or SAE 75W-140 SAE 75W-90 or SAE 75W-140