What This Air Spring Is
This is a reversible sleeve air spring for the drive axle on the Freightliner AirLiner suspension. The rubber bellows rolls over an aluminum piston instead of using a folded convoluted bag, so it gives a softer rate and longer travel. It carries load and sets ride height. It is not a shock and it does not damp anything on its own.
Built dimensions are 23.0 in extended height and 8.75 in compressed height. The top plate is the 3191 style, 9.00 in, with a combo stud air inlet. The lower mount is a 10.62 in aluminum piston, 9607 style. Those four things — extended height, compressed height, plate style, piston diameter — are what actually determine whether the bag bolts in.
It fits Freightliner drive axle applications on AirLiner suspension across the conventional FLD, Classic and Century era, plus 2001-2011 Columbia and the M2 Business Class. Cross-reference gets you close. Confirm against the number stamped or tagged on the bag you pull off, or by VIN, before you order a set.
Why These Numbers Cross
Freightliner did not build its own air springs. It specified a bellows and mount package from a supplier and gave it a chassis number, A16-14004-000, with 681-320-0017 showing up as a related Freightliner reference. The supplier carried the same assembly under its own catalog number. That is why one physical part shows up under half a dozen part numbers depending on which counter you walk up to.
Firestone lists the assembly as W01-358-9781 with the bellows itself marked 1T15ZR-6 — that bellows code is often the only thing legible on a bag that has been on the truck ten years. Goodyear catalogs the same envelope as 1R12-603. ContiTech shows 161007, with 9 10S-16 A 382 as the molded bellows marking. Hendrickson lists 8536. Volvo carries it as 85101151.
All of these describe the same reversible sleeve geometry: same extended and compressed heights, same 9.00 in top plate with combo stud inlet, same 10.62 in piston. Different rubber compounds and plate hardware do exist between brands, so check the inlet fitting and stud pattern against your old bag. Listing another manufacturer's number here is for identification only.
How These Bags Fail
The usual failure is a split or pinhole where the bellows rolls over the piston. Road grit packs into the sleeve area and abrades the rubber every cycle. You will see one corner sitting low overnight, hear the compressor cycling more than it should, or find the leveling valve fighting to keep the axle up. Soap the bag with the system aired up and look for bubbling along the roll.
The other killer is running a bag out of range. A dead shock lets the axle hammer the bag past its compressed height. A bent or corroded piston tears the sleeve from the inside. Replace both bags on an axle together, check the shocks, and verify the leveling valve links are straight and the valve returns to neutral. A new bag on a bad valve fails the same way.
W01-358-9781 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-9781. 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 | 161007, 9 10S-16 A 382 |
| Firestone | 1T15ZR-6 |
| Freightliner | A16-14004-000, 681-320-0017 |
| Goodyear | 1R12-603 |
| Hendrickson | 8536 |
| Volvo | 85101151 |
Frequently asked questions
My old bag only has 1T15ZR-6 stamped on it — is that the same as W01-358-9781?
1T15ZR-6 is the bellows marking molded into the rubber; W01-358-9781 is the complete assembly number including the top plate and piston. They refer to the same air spring. Still check the top plate style and piston diameter, because a bellows code alone does not confirm the mount hardware matches.
Do I have to replace both drive axle air springs at once?
Replace them in pairs on the same axle. An old bag next to a new one gives you uneven spring rate and the truck will lean or fight the leveling valve. If both bags have the same road time, the second one is usually close behind the first. Inspect the shocks and the leveling valve linkage while you have the axle apart.
Will this fit my Columbia if the chassis tag lists A16-14004-000?
A16-14004-000 is the Freightliner number that crosses to this assembly, so it is a strong indicator. We still cannot promise fitment from a number alone — trucks get resuspended and bags get substituted over a service life. Confirm by VIN or by measuring the extended height, plate style and piston diameter on the bag you remove.
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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