What This Air Spring Does
This is a drive axle bag, not a trailer or cab bag. It sits on the rear tandem of a Freightliner tractor running the AirLiner or FAS AirLiner II suspension and carries the loaded weight of the drive axles while the height control valve meters air in and out to hold ride height.
The design is a reversible sleeve over a lightweight composite piston. Extended height is 23.0 inches, collapsed height is 8.75 inches, and maximum diameter runs about 10.6 inches. The top is a 9-inch two-stud bead plate with a 1/4 NPT air inlet, which is what you match first when you compare an old bag to a new one.
When it fails you lose load equalization across the tandem. The truck sits low on one corner, the frame rides on the bump stops over rough pavement, and the axle that still has air takes the abuse. Tire wear on one side of the tandem is a common tell before anyone notices the ride height is off.
Why These Numbers Cross
Air springs cross on physical geometry, not on branding. W01-358-9780, Goodyear 1R12-303 and 1R12-189, ContiTech 9 10S-16 P 382 and 67473, Neway G2299780200, Triangle AS-8382P and Watson&Chalin AS-0147-1G all describe the same reversible-sleeve assembly with the same extended and collapsed heights, the same bead plate stud pattern, and the same 1/4 NPT port location.
Freightliner 16-13810-000 is the chassis builder's own number for the bag installed on the AirLiner and FAS AirLiner II drive-axle suspension. Suspension houses and axle builders each assign their own catalog number to the bag they buy, which is why one part carries eight identities. They are listed here for identification only — PartStop is not affiliated with or authorised by any of these manufacturers.
PartStop's aftermarket bag is a direct replacement built to those same dimensions. It is a starting point for identification, not a fitment promise. Confirm by VIN or by reading the number stamped or tagged on the bag you are pulling off the truck before you order.
Checks Before You Order
Get the old bag clean and find the label on the bead plate or the piston. Suspension swaps and prior repairs happen, so a Cascadia does not automatically mean an AirLiner bag is on it. Measure ride height at the axle before you tear into it so you have a reference number when you set the height control valve afterward.
Inspect the piston mounting stud, the bead plate studs and the air line fitting while the bag is off. A seized or stretched stud will fight you on reassembly. Replace in pairs or as a set across the tandem — mixing an old sagging bag with a new one leaves the truck sitting uneven and loads the new bag harder than it should be.
W01-358-9780 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-9780. 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 |
|---|---|
| ContiTech | 9 10S-16 P 382, 67473 |
| Freightliner | 16-13810-000 |
| Goodyear | 1R12-303, 1R12-189 |
| Neway | G2299780200 |
| Triangle | AS-8382P |
| Watson&Chalin | AS-0147-1G |
Frequently asked questions
Is 1R12-303 the same bag as W01-358-9780?
They cross to the same reversible-sleeve drive axle air spring with matching extended and collapsed heights, bead plate and air port. 1R12-189 crosses to the same assembly as well. Verify against the number on the bag you are removing, since the same chassis can carry more than one suspension configuration.
Can I replace just one bag on the tandem?
The part is sold each, so you can, but it is not the way to do it. A new bag next to an aged bag gives uneven ride height and uneven load sharing across the drive axles. Replace in pairs or as a set, then reset the height control valve to spec.
How do I know if it's the bag or the height control valve?
Air the system up and soap the bag, the bead plate seal and the 1/4 NPT fitting. A visible split, chafe hole or leak at the sleeve means the bag. If the bag holds air but the corner still sits low, check the height control valve linkage and the valve itself before condemning the spring.
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.