What You're Actually Buying
This is a cabin air filter, not an engine air filter - different job entirely. It sits in the HVAC housing behind the dash or under the hood on the firewall side, depending on the truck, and it's what keeps dust, pollen, and diesel exhaust smell out of the cab air.
Peterbilt, Kenworth, and International all sourced this filter from the same HVAC system supplier over the years, which is why one filter cartridge covers a 579, a T660/T680, and an LT. Cab and engine specs vary, but the HVAC box and filter slot didn't change across these platforms for a long stretch of production.
P640110 is the aftermarket cross for that OE filter - same media pleat count, same frame dimensions, built to slide into the stock housing without modification.
Why These Numbers Cross
1AMFC00025, 4070948C1, X1987001, 1987001, TR555, and Fleetguard AF55839 all point back to the same physical filter. International uses the 4070948C1 designation in their parts books, Kenworth/PACCAR uses the 1987001 family, and TR555/AF55839 are aftermarket house numbers from different suppliers making the identical part.
What to actually check before you order: filter frame dimensions (length x width x depth) and whether your housing uses a single filter or a dual-filter setup - some T680 sleeper configs run two smaller filters instead of one. Pull the old filter and measure it, or better yet read the number stamped or printed on the frame.
Don't go by year or model alone. HVAC suppliers changed mid-production on some of these trucks, so a 2015 T660 might not match a 2019 one. VIN lookup or physical part number off the old filter is the only way to know for sure.
Ordering From PartStop
We stock P640110 at the Tacoma counter for walk-ins and same-day will-call - fleet guys running local routes can grab one on a lunch break. Ships nationwide if you're not in the area, usually out same day if you order before early afternoon.
Comes with our standard 6+ month warranty. If it doesn't seat right in your housing or the dimensions are off from your old filter, call us before you toss the packaging - we'll sort out a return or exchange.
One filter, three truck brands, decent price point at $19 - just confirm the number matches what's coming out of your dash before you commit.
P640110 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to P640110. 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 |
|---|---|
| Cross-Reference | 1AMFC00025, 4070948C1, X1987001, 1987001, TR555 |
| Fleetguard | AF55839 |
Frequently asked questions
Does P640110 fit my 2021 Kenworth T680?
Likely yes, T660/T680 production from 2004-2024 generally uses this filter family, but HVAC suppliers changed at points during that run. Pull your old filter and check the number stamped on the frame, or run your VIN to confirm before ordering.
Is this the same as Fleetguard AF55839?
Yes, AF55839 is Fleetguard's part number for this same filter - different label, same media and frame dimensions. Either one should drop into the same housing.
My International LT has two filter slots in the HVAC box, will one P640110 cover both?
No, if your housing is a dual-filter setup you need two units, one per slot. Single vs dual filter configuration varies by build, so check your housing before ordering - don't assume from the truck model alone.
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.