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1st Generation 5.9L Cummins Maintenance Guide & Parts List

How do I properly Maintain my 1st Gen 12V Cummins Pickup Truck?

If you’re reading this, it probably means you’re the proud owner of a 1989-1993 Dodge Ram D/W pickup truck. These trucks are the first generation of Dodge Ram Pickups available with a diesel engine. The diesel engine in these trucks is no ordinary engine however, they’re one of the most durable diesel engines ever built. Just because they have a reputation for durability, doesn’t mean that you should take a chance when it comes to proper maintenance though. With how easy it is to work on these trucks, there is no excuse for not taking care of one. I’ll cut you some slack though, it’s not easy finding the right parts and your truck might not have come with an owner’s manual. Don’t worry about it. You’ve come to the right place! We make taking care of your truck easy with our comprehensive 1st Generation 5.9L Cummins Maintenance guide.

Our 1st Gen 5.9L 12V maintenance guide gives you the proper service schedule to follow and detailed information pertaining to fluid capacities and specifications. We’ll even give you the exact parts you’ll need and links to where you can find them on Amazon. Assuming you have the parts you need at your home, you won’t have to go the store to pick anything up. All you need is a little bit of mechanical know-how and be willing to learn. If you need to learn a little bit before hand, spend a little time on Youtube. Changing fluids and filters is very easy, even for a beginner mechanic or a DIYer.

First Gen Cummins Maintenance and Fluid Capacity Guide
Over 30 years have gone by and this first generation Cummins is still hauling every day. Do you think maintenance played a role? Of course it did.

When Should I Service My Truck?

If you just bought your 12V Cummins, I would strongly recommend giving it a maintenance overhaul immediately. You don’t know how it was treated in the past. They could’ve worked the truck really hard or used it for work. If it’s a previous fleet vehicle, it probably wasn’t serviced as frequently as it should be. You also don’t know if the previous owner or the dealer you just bought it from used the proper fluids, filters, or engine oil. Don’t take the unnecessary risk! Just go ahead and service the truck as soon as you can.

If you’ve owned the truck for a while, maybe you’re just unsure of if you’ve been following the proper service schedule. Take a look at the mileage of your truck, and see where you’re at in comparison to the chart below. I recommend changing fluids every year or couple of years. Don’t be afraid of performing maintenance sooner than the mileage requirement. Fluids, oil, and parts can lose quality and degrade over time too. It’s better to perform maintenance too soon than being too late. Always keep in mind, the better you treat your truck, the better she will treat you.

What is the Correct 1st Generation 5.9L Cummins Service Schedule?

Follow the 1st Generation 5.9L Cummins maintenance schedule below like your life depends on it. Just remember, there are other parts that could fail that might need to be replaced too. Check out our section about things you should do every oil change to make sure you can catch problems like front end and steering problems early.

Normal Operating Conditions Service Schedule

Maintenance/ServiceMilesKilometersMonths
Change Oil6,000 miles9,600 km6 mo.
Change Oil
Filter
6,000 miles9,600 km6 mo.
Replace Fuel
Filter
12,000 miles19,200 km12 mo.
Replace Engine Air
Filter
Check Every Service
interval, replace
as necessary.
See LeftSee Left
Flush Cooling
System (Initial flush)
36,000 miles57,600 km36 mo.
Flush Cooling
System (After Initial flush)
30,000 miles48,000 km24 mo.
Drain & Re-Fill
Automatic Transmission
Fluid
24,000 miles38,400 km24 mo.
Replace automatic
transmission Filter(s)
24,000 miles38,400 km24 mo.
Adjust Automatic
Transmission Band
24,000 miles38,400 km24 mo.
Flush & Re-fill
Manual Transmission
Fluid
60,000 miles96,000 km36 mo.
Replace Transfer
Case Fluid
36,000 miles57,600 km36 mo.
Adjust Valve
Lash
24,000 miles38,400 km24 mo.
Replace Rear
Differential Fluid
Not Specified by FCA,
at least once every
100,000 miles or
5 years
See LeftSee Left
Replace Front
Differential Fluid
Not Specified by FCA,
at least once every
100,000 miles or
5 years
See LeftSee Left

Severe Operating Conditions Service Schedule

The following chart is the 1st Generation Cummins Maintenance schedule to follow if you frequently tow, idle, or drive in city conditions. If you use your truck for work, or if you beat on your truck, this is the First Gen Cummins service schedule for you.

Maintenance/ServiceMilesKilometers
Change Oil3,000 miles4,800 km
Change Oil
Filter
3,000 miles4,800 km
Replace Fuel
Filter
6,000 miles9,600 km
Replace Engine Air
Filter
Check Every Service
interval, replace
as necessary.
See Left
Flush Cooling
System (Initial flush)
36,000 miles57,600 km
Flush Cooling
System (After Initial flush)
30,000 miles48,000 km
Drain & Re-Fill
Automatic Transmission
Fluid
12,000 miles19,200 km
Replace automatic
transmission Filter(s)
12,000 miles19,200 km
Adjust Automatic
Transmission Band
24,000 miles38,400 km
Flush & Re-fill
Manual Transmission
Fluid
60,000 miles96,000 km
Replace Transfer
Case Fluid
36,000 miles57,600 km
Adjust Valve
Lash
24,000 miles38,400 km
Replace Rear
Differential Fluid
12,000 miles19,200 Km
Replace Front
Differential Fluid
12,000 miles19,200 Km

1st Generation Cummins Fluid Capacity

Another important factor in first generation Cummins maintenance is fluid capacity. You want to make sure you know how much fluid or oil you need to purchase before servicing your truck. The last thing you want to do is drain your truck of fluid or oil, only to find out you didn’t buy enough to properly re-fill your truck. Take a look at our 1st Gen 5.9L Cummins Fluid Capacity chart below.

Oil/FluidCapacity – QuartsCapacity – Liters
Engine Oil /w Filter12 Quarts11.4 Liters
Auto Transmission Fluid
47 RE/RH
————–
A727
See Below
4 Quarts Service Refill
14.5-16.5 Quarts dry refill
11 Quarts
See Below
3.8 Liters
8.2-15.6 Liters
10.4 Liters
Manual Transmission Fluid
Getrag G360
NV4500
See Below
3.5 Quarts
4 Quarts
See Below
3.3 Liters
3.8 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
Coolant24-26 Quarts22.7-24.5 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

1st Gen Cummins Maintenance Parts

Using high quality parts, filters, and fluids is so important in proper 1st Generation Cummins Maintenance. Finding the best parts and fluids to use is difficult because the 1st gen Cummins is old. To make it easy on our readers and fellow diesel lovers, we compiled a list of the most common first gen Cummins maintenance parts. Take a look at the chart below. Click on the links below if you’d like to purchase the parts from Amazon! The prices are great and the shipping is awesome for Amazon Prime members.

Part TypePart #Amazon Link
Engine Oil15W40Shell Rotella T4 15W40
Shell Rotella T5 (blend ) 15W40
Shell Rotella T6 15W40
Engine Oil FilterLF16035
LF3972
Fleetguard Stratopore LF16035
Fleetguard LF3972
Fuel FilterFS1232
FS1251
Fleetguard FS1232
(/W Water/Fuel Sensor)
Fleetguard FS1251
(No Water/Fuel Sensor
Engine Air Filter
’89-’92
’93
Years
AF4555M
AF25023
Filters
Fleetguard AF4555M
Fleetguard AF25023
CoolantN/A50-50 Mixture of Distilled Water
and glycol ethylene coolant
Automatic
Transmission Fluid
ATF+4Mopar ATF+4
Manual
Transmission Fluid
5W30 Engine
Oil
5W30 Motor Oil
Serpentine Belts
Intercooled /w AC
Non-Intercooled /w AC
Intercooled No AC
Non-Intercooled No AC
See Below
K080830HD
K080816HD
K080635
K080645
See Below
Gates K080830HD (‘91.5-’93)
Gates K080816HD (’89-’91)
Gates K080635 (‘91.5-’93)
Gates K080645 (’89-’91)
Upper Radiator Hose
89-91 Non-Intercooled
‘91.5-’93 Intercooled
See Below
20957
21930
See Below
Gates 20957
Gates 21930
Lower Radiator Hose20431Gates 20431
Transfer Case FluidATF4+Mopar ATF+4
Front Differential
Fluid
SAE 80W-90SAE 80W-90
Rear Differential FluidSAE 80W-90SAE 80W-90

Learn More About the First Generation Cummins

Click on one of the links below to view some of our other first generation Dodge Cummins diesel resources.

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ABOUT Kamil

Founder of Diesel Resource and a complete diesel head. Has a little bit of problem buying too many trucks. Learn more about him by checking out his truck.