What This Air Spring Is
This is a 1T reversible-sleeve air spring for the front, or steer, axle suspension. Stud top, stud bottom. Roughly 6-15/16 in. maximum diameter, 5-1/8 in. compressed height and 15-3/4 in. extended height. The reversible sleeve design rolls the rubber over the piston instead of folding it, which is why these ride softer than a convoluted bag and why sleeve wear shows up as a wear line rather than a crack.
It mounts to the Hendrickson 60750-2 front air bracket used on Volvo VNL, VNR, VHD and VNX tractors and on Mack heavy-duty chassis. The bracket number matters as much as the truck model here. Two trucks of the same model year can carry different front bracket setups depending on how the chassis was specced, and the bag has to match the bracket, not the badge on the hood.
Fitment on this listing is a starting point. Confirm by VIN or by reading the number stamped or tagged on the bag you are pulling off. If the old bag is shredded and the tag is gone, measure compressed height and check the stud pattern before ordering.
Why These Numbers Cross
Firestone W01-358-9913 and the Airide catalog number 170/127 describe the same physical assembly as W26-358-9913. The W01 and W26 prefixes are packaging and channel designations from the same product family. ContiTech 69915 is that maker's build of the same reversible-sleeve bag with matching mounting hardware and stroke.
Hendrickson 66349-2 is the suspension builder's service number for the air spring installed on the 60750-2 front bracket. Volvo 20897204 and Mack 57QL55M are the truck makers' own service numbers for the same bag as fitted at the plant. Torque TR9913 is an aftermarket line's number for the same part. All of them describe one bag: same diameter, same collapsed and extended heights, same stud top and stud bottom.
These numbers are listed here for identification only. PartStop is not affiliated with, endorsed by, or authorized by any of the manufacturers named. Listing a number does not mean the part came from that manufacturer or that they stand behind it.
How These Bags Fail
Reversible-sleeve bags on the steer axle usually die one of three ways. The sleeve chafes through where it rolls against the piston, often from road grit packed into the rolling area. The bead unseats at the top plate after the truck has been run down on a dead bag. Or the stud corrodes and snaps when someone torques it after twenty winters of salt.
Before you order, soap the bag at full ride height and again with the truck dumped. Check the piston for scoring, check the bracket for cracks around the stud holes, and look at the height control valve linkage. A bag that keeps failing early usually means the valve is holding the wrong ride height and the sleeve is running past its designed stroke.
W26-358-9913 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W26-358-9913. 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 | 69915 |
| Firestone | W01-358-9913, 170/127 |
| Hendrickson | 66349-2, 60750-2 |
| Mack | 57QL55M |
| Torque | TR9913 |
| Volvo | 20897204 |
Frequently asked questions
Is this the same as Firestone W01-358-9913?
It is a direct replacement for that number. W01-358-9913 and W26-358-9913 refer to the same reversible-sleeve air spring with the same stud top and stud bottom mounting and the same height range. Confirm the number on the bag you are removing before you order.
Will it fit my Volvo VNL if the old bag has no tag?
Do not assume. Check the front bracket number and measure the old bag. This spring is built for the Hendrickson 60750-2 front bracket, roughly 6-15/16 in. diameter with 5-1/8 in. compressed and 15-3/4 in. extended height. Verify by VIN or by the number on the old part before ordering.
Do I replace both steer axle bags at once?
Standard shop practice is to replace in pairs. A new bag on one side and a worn one on the other gives you uneven ride height and drags the height control valve out of range. If one sleeve has worn through, the other has seen the same miles and the same grit.
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.