What This Filter Is and Where It Goes
This is the primary engine air filter for Freightliner Cascadia trucks roughly 2008 through 2024, depending on engine and housing setup. It's a radial seal design - meaning the filter seals against the inside wall of the housing instead of the end cap, which is why fit matters more than it looks like it should.
Kenworths that share this same Donaldson-based housing will also take this filter, but Kenworth doesn't always use the same part number for the same physical filter, so don't go by truck brand alone. Go by the number on the old filter or your air cleaner housing tag.
How the Cross Numbers Actually Line Up
AF27879 crosses to Freightliner's own AF56500, and both of those cross to aftermarket numbers like P610260 and P618478. These aren't random substitutes - they're the same filter made to the same dimensional spec, just labeled under different catalogs (Freightliner house brand, Donaldson-pattern aftermarket, etc.).
Where guys get burned on radial seal filters is diameter and depth - if the housing is even a little off, the seal doesn't bite right and you get dust bypass, which eats turbos and rings. Pull the old filter and check the number stamped on the end cap or the sticker on the housing before you order. If numbers don't match what's listed here, don't force it - call us with your VIN and we'll check the actual air cleaner housing part number.
Ordering From PartStop
We're in Tacoma and keep these in stock for same-day will-call or same-day local delivery if you're broke down and can't wait on freight. Outside the Puget Sound area we ship nationwide, usually next-day to most West Coast terminals.
Every filter we sell carries our 6+ month warranty. If you get it in hand and the housing doesn't match up, send it back before you force-fit it - a bent end cap on a return is a lot cheaper than a chewed-up turbo from a bad seal.
AF27879 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to AF27879. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Freightliner (OEM) | AF56500 |
| Aftermarket | P610260, P618478 |
Frequently asked questions
Does AF27879 fit my 2015 Cascadia with a DD15?
Likely yes, but confirm by checking the old filter's stamped number or the tag on your air cleaner housing - Cascadias ran a couple different housing sizes over the years depending on engine and cab config, so match the number, not just the year.
Is P610260 the same filter as AF27879?
Yes, P610260 is an aftermarket cross for the same physical filter - same dimensions and seal spec. We'd still tell you to check your old part number first since housing updates over the years can change what actually fits your truck.
My old filter has AF56500 on it, will this one work?
That's the Freightliner house-brand number for this same filter, so AF27879 should interchange fine. Double check by comparing outer diameter and height against your old core before you install it, especially if the truck's had any air intake work done.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.