What This Filter Is and Where It Lives
This is a cabin filter, not an engine air filter — different job entirely. It sits behind the glovebox or under the dash in the HVAC housing on Cascadias, filtering the air that blows on your driver and gets sucked into the cab. Twenty years of Cascadia production means Freightliner didn't change this housing much, so one filter number covers a long run of trucks.
P609422 is a panel-style filter, pleated media in a frame. Nothing fancy, no motors or electronics involved — it's a wear item like wiper blades. Cabs get dusty, filters load up, airflow drops, and eventually you smell it before you see it. Twelve to eighteen months or 30-40k miles is the usual swap window depending on how dirty your routes are.
Why These Numbers Cross and What to Check
Alliance N10G 91560 and N10G 91559 are the same physical filter under Freightliner's own parts brand, sized and pleated to match this housing. AF26235 is another aftermarket cut of the identical filter. They cross because they're built to the same dimensions and media spec Freightliner engineered for the Cascadia's HVAC box — same length, width, depth, and gasket seal around the frame.
Where guys get tripped up is Cascadia trim changes over 20 years sometimes moved the HVAC box slightly, or a truck's had aftermarket AC work done that changed the housing. Filter looks close, doesn't seat right, air leaks around the edges instead of through the media. Pull your old filter and match the frame dimensions and any part number stamped on it before you order — that's your surest confirmation, not just the model year.
If there's no number on the old filter or it's worn off, VIN lookup or a call to us with your build date works too. We'd rather spend two minutes confirming than have you shipping a filter back.
Ordering From PartStop
We're in Tacoma and keep P609422 on the shelf — same-day pickup if you're local, and we ship nationwide if you're not. Cabin filters aren't glamorous but they're also not something you want backordered when your blower's coughing dust at you.
Comes with our standard 6+ month warranty. At $18.99 it's cheap insurance against a musty cab and a clogged HVAC system — way cheaper than a shop diagnosing why your defrost is weak.
P609422 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to P609422. 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 |
|---|---|
| Alliance | N10G 91560, N10G 91559 |
| Aftermarket | AF26235 |
Frequently asked questions
Does P609422 fit my 2019 Cascadia?
Most likely yes — this filter spans the 2004-2024 Cascadia run since Freightliner kept the HVAC housing consistent. Still, pull your old filter and check dimensions or part number stamped on the frame, or give us your VIN and we'll confirm before you order.
Is this the same as the Alliance N10G 91560?
Same filter, different brand label. Alliance is Freightliner's own parts channel number, N10G 91560, and it cross-references to this aftermarket P609422 — same size, same pleat pattern, same fit in the housing.
How do I know it's time to change it?
Weak airflow from the vents, musty smell when the AC or heat kicks on, or visible dust/debris when you pull it out. If you're running dusty routes or gravel roads a lot, check it more often than the 12-18 month average.
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.