Mopar 68436631AA vs 68157291AA: What’s the Difference?

If you are shopping for a fuel filter for a Ram 6.7L Cummins, two Mopar part numbers appear together often enough to cause confusion: 68436631AA and 68157291AA.

They are not simply two versions of the same filter.

For applicable later-model Ram 6.7L Cummins trucks, the two part numbers refer to different components within the fuel-filtration system. Mopar identifies 68157291AA as a fuel filter, while 68436631AA is identified as a fuel/water separator filter kit.

That distinction matters when you are ordering mopar filters, because choosing a part based only on “6.7 Cummins” can lead to the wrong component.

68436631AA vs 68157291AA: The Basic Difference

The easiest way to understand the two numbers is to look at what each part is identified as.

Mopar 68157291AA is identified as a fuel filter. It is used across applicable Ram 6.7L Cummins applications and is listed across multiple model years.

Mopar 68436631AA, on the other hand, is identified as a fuel/water separator filter kit. Its role within the fuel-filtration system is different from simply treating it as another version of 68157291AA.

In simple terms:

• 68157291AA: Fuel filter
• 68436631AA: Fuel/water separator filter kit
• They are not interchangeable simply because both are associated with 6.7L Cummins applications.
• On applicable later-model Ram trucks, both can be part of the fuel-filtration service.

That last point is where many parts searches become confusing.

Why Do Both Part Numbers Appear Together?

If you have searched for a 2019–2024 Ram 2500 or 3500 fuel filter, you have probably seen listings containing 68157291AA + 68436631AA.

There is a reason. The later Ram 6.7L Cummins fuel-filtration system uses more than one filtration component. The two Mopar part numbers represent different components within that system rather than two alternative versions of the same part.

This means a listing containing both numbers is not necessarily offering two choices. For an applicable vehicle, it can represent the two different filters required for a complete fuel-filtration service.

That is also why replacing only one filter when both are due may not constitute a complete fuel-filter service.

The important qualification is application. The exact configuration depends on the truck and model year, so the part number should always be checked against the vehicle rather than assuming that every 6.7L Cummins uses the same arrangement.

What Does Mopar 68157291AA Do?

Mopar identifies 68157291AA as a fuel filter. Its purpose is to remove impurities from the fuel before that fuel continues through the engine's fuel system.

The part number is listed for applicable 6.7L Cummins applications across several Ram model years. That model-year range is worth paying attention to.

Seeing 68157291AA listed for both older and newer trucks does not mean the complete fuel-filter system is identical across all of those vehicles. Other components in the system can change between generations.

For example, earlier Ram 2500 and 3500 applications use 68157291AA within a fuel-filter assembly that includes other components associated with fuel and water separation.

So if you are replacing a filter on an older truck, do not use the presence of 68157291AA alone as proof that every other component from a later application will fit.

What Does Mopar 68436631AA Do?

The 68436631AA part number is different.

It is identified as a fuel/water separator filter kit. Water separation is an important function within a diesel fuel system because water contamination needs to be separated from the fuel before it can continue through the system.

The separator is therefore not simply a duplicate of the 68157291AA fuel filter.

For applicable later-model Ram applications, 68436631AA is associated with the fuel/water-separator side of the filtration system. This distinction becomes particularly useful when you are looking at complete filter kits and trying to understand why two different Mopar numbers are listed together.

Which One Does a 2019 - 2024 Ram 6.7 Cummins Need?

This is where the answer becomes more useful than simply comparing two part numbers.

For applicable 2019–2024 Ram 2500, 3500, 4500 and 5500 6.7L Cummins applications, both 68157291AA and 68436631AA can be listed as part of the fuel-filtration service.

So if you are servicing a compatible later-model truck and your maintenance requirements call for both fuel-filtration components, you should not treat 68436631AA and 68157291AA as an either/or choice.

Instead, think of them as two different part numbers serving different roles within the vehicle's fuel-filtration system.

This is also why dual-filter kits can be useful for owners performing a complete fuel-filter service. Rather than purchasing one component and later discovering that another filter is also due, a correctly matched kit can bring the required components together.

What About a 2013–2018 Ram?

This is where you should be careful about copying a later-model parts list onto an older truck.

68157291AA is associated with applicable Ram applications across multiple model years, but 68436631AA is associated with later applications. The presence of the same fuel-filter part number across different model years does not mean that the entire filtration system remained unchanged.

For a 2013–2018 Ram 2500 or 3500, verify the complete application before ordering. The fuel-filter housing, separator components and associated part numbers should be matched to the truck's actual model year and configuration.

Should You Buy 68157291AA or 68436631AA?

If you are trying to decide between the two, start with the truck, not the product name.

Before ordering, check:

• Model year
• Ram model - 2500, 3500, 4500 or 5500
• Engine - 6.7L Cummins
• Existing filter part number
• Whether you are replacing one component or performing a complete fuel-filter service

For a compatible 2019–2024 application, seeing both 68157291AA and 68436631AA in a complete fuel-filter listing is normal. The two numbers should be viewed as different components rather than competing versions of the same filter.

If you are working on an earlier truck, do not assume that the same combination applies.

Common Mistakes When Ordering Ram Fuel Filters

Assuming Both Part Numbers Are Interchangeable

This is the biggest mistake. They are different components, even though they may appear together in a product listing.

Searching Only by Engine Size

“6.7 Cummins” covers multiple Ram model years and filtration configurations. The engine designation alone is not enough to establish fitment.

Buying One Filter When a Complete Service Requires Two

On applicable later-model systems, 68157291AA and 68436631AA can form part of the same fuel-filtration service. Check what your specific truck requires before ordering an individual component.

Assuming an Older Application Is Identical to a Newer One

A part number can remain applicable across several years while other components in the surrounding system change. Always verify the complete vehicle application.

Frequently Asked Questions

Is 68436631AA the same as 68157291AA?

No. 68157291AA is identified as a fuel filter, while 68436631AA is identified as a fuel/water separator filter kit. They perform different roles within applicable fuel-filtration systems.

Do 68157291AA and 68436631AA work together?

For applicable later-model Ram 6.7L Cummins applications, both part numbers can be listed together as part of the fuel-filtration service. They should be treated as separate components rather than interchangeable alternatives.

Does 68157291AA fit a 2013–2018 Ram 6.7 Cummins?

68157291AA is listed for applicable Ram 6.7L Cummins applications across multiple model years. However, complete filter-system compatibility depends on the specific vehicle configuration, so verify the application before ordering.

Is 68436631AA used on 2019 Ram 2500 and 3500?

68436631AA is associated with applicable later-model Ram 6.7L Cummins fuel/water-separator applications, including 2019 Ram 2500 and 3500 configurations. Always verify the exact vehicle application before purchasing.

Can I buy just one of the two filters?

Individual components may be purchased separately where available, but whether you need one or both depends on what your specific truck requires and which part of the fuel-filtration system is being serviced.

How do I choose the correct Mopar filter for my Ram?

Use the truck's model year, model, engine and existing part number together. If those details do not provide a clear match, verify the application through a VIN-based parts catalog or the vehicle manufacturer before ordering.

Conclusion

68436631AA and 68157291AA are not competing versions of the same Ram fuel filter. They are different Mopar part numbers associated with different filtration components.

For applicable later-model 6.7L Cummins Ram trucks, 68157291AA is the fuel filter, while 68436631AA is the fuel/water separator filter kit. Both can therefore appear together when a complete fuel-filtration service is being performed.

The safest approach is to identify your Ram by model year, truck model and engine, confirm the applicable part numbers, and then select the complete filter application rather than relying on a generic “6.7 Cummins filter” search.