What This Air Spring Is
This is a two-ply reinforced double convoluted bellows, the Firestone #22 size. It carries a 9.00 in top plate with blind-nut or stud mounting and a top air fitting, over a 9.00 in piston. Two lobes, not three, and no rolling sleeve. If the unit you pulled has a sleeve riding on a tapered piston, you are looking at a different family entirely.
On the tractor side it sits on pre-1990 Freightliner conventionals fitted with the FAS Airliner drive-axle air suspension. On the trailer side the same bellows shows up as a primary or auxiliary spring under Hendrickson, Ridewell, Neway, SAF-Holland and Watson & Chalin hardware. Same bag, different brackets and different plumbing.
The PartStop unit is an aftermarket direct replacement, not a factory part. It is built to the same convolution count, plate diameter and piston diameter so it drops into the existing bracket without spacers or drilled plates. Torque the top studs and the piston bolt to the suspension builder's figures, not to a generic value.
Why These Numbers Cross
Air spring interchange works because the bellows is a commodity size. Firestone assigned the #22 bellows to W01-358-7410, Goodyear catalogued the same envelope as 2B12-406, and ContiTech lists it as FD 330-22. The rubber, cord angle and convolution geometry are built to the same dimensional envelope, so the assembled height, stroke and effective area line up.
The suspension builders then re-stamp that assembly under their own part numbers for service. Hendrickson S-10170, Ridewell 1003587410C and SAF-Holland 57007410 are the same bag sold through those channels. Goodyear also carries 578-92-3-309 as an alternate listing for the same unit. Aftermarket houses add their own: Torque TR7410 and Triangle 4331.
The numbers only cross if the mounting hardware matches too. A #22 bellows can be sold with a stud top, a blind-nut top, or a bead-plate top, and with different piston bolt patterns. Read the plate on your old bag before you commit. These numbers are listed for identification only — PartStop is not affiliated with or authorised by any of these manufacturers.
Failure Signs And Pre-Order Checks
Typical failure is a split in the convolution fold or a crack where the bellows meets the bead ring. You will hear a hiss with the parking brake set and the system charged, or the truck will sit down on one corner overnight. Rust jacking under the top plate and chafe marks from a shifted bag are also common on older FAS Airliner units.
Before ordering, get the number off the old bag — it is usually moulded or stamped on the girdle hoop or printed on the top plate. Measure the top plate and piston diameter, count the convolutions, and note whether the air port is in the top plate or the side. Then confirm fitment by VIN or by that old number. A cross-reference is a starting point, not a fitment guarantee.
W01-358-7410 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-7410. 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 | FD 330-22 |
| Goodyear | 2B12-406, 578-92-3-309 |
| Hendrickson | S-10170 |
| Ridewell | 1003587410C |
| SAF-Holland | 57007410 |
| Torque | TR7410 |
| Triangle | 4331 |
Frequently asked questions
Is 2B12-406 the same bag as W01-358-7410?
They are catalogued as the same double convoluted #22 envelope by two different manufacturers. Plate and piston diameters and stroke are built to the same figures. Check that your top plate mounting style and air port location match before you swap, since the same bellows is sold with more than one hardware configuration.
Do I have to replace air springs in pairs?
Not strictly required, but it is normal shop practice on an axle. A new bag next to one with years of service will sit at a slightly different height and load unevenly. If the second bag shows fold cracking, bead ring rust or chafing, replace both while the axle is already unloaded.
How do I confirm this fits my Freightliner?
Pull the number off the old air spring and compare it against the list above, then verify with your VIN. FAS Airliner suspensions were built over a long run and brackets were changed. If the old bag was already a replacement, it may not match what the truck left the plant with — measure the plate and piston to be sure.
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
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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.