What This Air Spring Does
This is a reversible-sleeve rolling-lobe air spring for the rear drive axle on Class 8 Kenworth tractors. The bellows rolls down over a composite piston as the axle travels, so the rate stays soft loaded or empty. Collapsed height is 6.25 in, design height is 11.80 in, and maximum diameter is roughly 11.7 in.
It carries load and controls ride height in concert with the leveling valve and height control linkage. When the bag is healthy, the truck sits at spec ride height and the frame stays off the bump stops. When it isn't, you get axle hop, hard ride, and driveline angle complaints that get blamed on everything else first.
Failures show up three ways. Sidewall chafe from a dragging hose or a shifted bumper. A slow leak at the bead plate that drops one corner overnight. Or a burst lobe after the bag ran folded because ride height was set low. Check the piston for cracks and debris packed on top before you fit a new bag.
Why These Numbers Cross
Air springs are cataloged by physical envelope and mounting hardware, not by truck. Firestone W01-358-9541, Kenworth PACCAR C81-1005 and C81-1004, ContiTech 68357 and 9 9-10 P 861, Goodyear 1R11-268, Meritor FS9541 and MAF9541, and Torque TR9541 all describe a reversible-sleeve bag with the same collapsed and design heights, the same diameter, and the same top and bottom mount pattern.
Kenworth buys the bag and assigns its own dealer number, so C81-1005 and C81-1004 are the same hardware sold through the truck channel. Suppliers like ContiTech, Goodyear, Meritor and Torque build or brand to the identical envelope so a fleet can source from whoever answers the phone. That is why one bag replaces all of them.
These numbers are listed for identification only. PartStop is not affiliated with, endorsed by, or authorised by Firestone, Kenworth, PACCAR, ContiTech, Goodyear, Meritor or Torque. The cross-reference is a starting point — confirm by VIN or by the number printed on the bag you pulled off.
Check Before You Order
Identify the suspension first. Airglide 200 built 05/05/03 or later, Airglide 460, and Airglide 690 use this drive-axle bag. Earlier Airglide 200 builds are a different setup. Look at the suspension tag or the build sheet rather than guessing from the model badge, because T680, T800, T660, T700 and W900 chassis were built with more than one rear suspension.
Then confirm the mounting. Note whether the top plate uses studs or a blind nut, check the air inlet location, and measure your current ride height against the axle stop. Replace bags in pairs across the axle so ride height stays even, and reset ride height with the leveling valve after the install.
W01-358-9541 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-9541. 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 | 68357, 9 9-10 P 861 |
| Goodyear | 1R11-268 |
| Kenworth | C81-1005, C81-1004 |
| Meritor | FS9541, MAF9541 |
| Torque | TR9541 |
Frequently asked questions
Is C81-1005 the same bag as W01-358-9541?
They describe the same reversible-sleeve drive-axle air spring. C81-1005 is the Kenworth PACCAR dealer number and W01-358-9541 is the Firestone number for the same envelope and mounting. C81-1004 also appears on these applications. Confirm against the number on your old bag or by VIN before ordering.
How do I tell which Airglide suspension I have?
Check the suspension identification tag on the frame rail or hanger, or pull the build sheet by VIN. This bag covers Airglide 200 built 05/05/03 or later, Airglide 460 and Airglide 690 rear drive-axle setups. Model name alone won't tell you, since the same tractor model was built with more than one suspension.
Do I have to replace both bags at once?
Replace them in pairs on the same axle. A new bag next to an old one gives you uneven ride height and uneven load share, and the older bag is usually close to failing anyway. After the swap, verify and reset ride height at the leveling valve to spec.
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.