What This Air Spring Does
This is a cab/sleeper mount air spring, not a suspension bag. It sits between the cab or sleeper structure and the frame, and its only job is isolating the driver from road shock the chassis suspension already passed through. When it fails, the truck still drives, but the cab bangs and the driver feels every expansion joint.
Physical size is 6.75 in. diameter, 2.40 in. compressed height, 8.75 in. extended height. Maximum rating is 100 psi. The mount is a bottom internal thread with a top alignment stud, so the bag threads to the lower bracket and the stud locates it in the upper plate. Measure your old bag before ordering.
The sleeve design means the rubber rolls over a piston rather than folding like a convoluted bag. Sleeves fail differently: they chafe through at the roll point, or the crimped end lets go. Either way you get a leak that empties the cab air circuit overnight and leaves the cab sitting on its bump stops in the morning.
Why These Numbers Cross
W02-358-7087, Goodyear 1S5-040, ContiTech SC29-W087, Triangle AS-5087, Torque TR7087, Automann ABSZ70-7087, TRP AS70870, Dayton 453-7087L and Freightliner GYR1S5040 all describe the same physical sleeve bag. Same 6.75 in. diameter, same 2.40 in. compressed and 8.75 in. extended heights, same bottom internal-thread and top-stud mounting arrangement.
The reason so many numbers exist is that the air spring was built to a Freightliner cab-mount envelope and then catalogued independently by every supplier that served that market. Goodyear used a 1S series index, Firestone used the W02 sleeve family, and the rest built their numbers off whichever of those two they were referencing. None of that changes the part in the box.
These numbers are listed for identification only. PartStop is not affiliated with, endorsed by, or authorised by Firestone, Goodyear, ContiTech, Freightliner or any other manufacturer named here. The cross-reference is a starting point. Confirm fit by VIN or by reading the number stamped or tagged on the bag you are pulling off.
Check Before You Order
Pull the old bag and look for a moulded or tagged number on the end cap. That number is the most reliable thing you have. If the tag is gone, measure diameter and extended height with the bag off the truck, and check the mount style — internal thread at the bottom, stud at the top. Sleeve bags in this size range look alike and mount differently.
Replace in pairs where the cab uses two. A new bag beside a tired one leaves the cab sitting off level and loads the new one unevenly. While the bag is out, inspect the air line and fitting at the bottom port, the levelling valve linkage if fitted, and the shock or damper at that corner. A collapsed bag often means the leak has been feeding for months.
W02-358-7087 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W02-358-7087. 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 |
|---|---|
| Automann | ABSZ70-7087 |
| ContiTech | SC29-W087 |
| Dayton | 453-7087L |
| Freightliner | GYR1S5040 |
| Goodyear | 1S5-040 |
| TRP | AS70870 |
| Torque | TR7087 |
| Triangle | AS-5087 |
Frequently asked questions
Will this fit my FLD if I do not know the exact model code?
Pre-2002 FLD conventionals often fall outside current model code lookups, which is why the old part number matters more than the year. Read the number off the bag you are removing and compare it to the cross-reference list. If the tag is unreadable, measure the bag and verify by VIN before ordering.
My cab drops overnight but I cannot hear a leak. Where do I look?
Air the system up, then soap the crimped ends of the bag and the roll area where the sleeve folds over the piston. Sleeve bags commonly chafe through at the roll point and the leak is small enough to be silent. Also soap the bottom air fitting and the line, since fittings loosen with cab movement.
Is this the same bag as the rear suspension air spring?
No. This is a cab/sleeper mount air spring rated to 100 psi, sized 6.75 in. diameter with 2.40 in. compressed and 8.75 in. extended height. Suspension bags are larger and carry chassis load. Do not substitute one for the other, and confirm the position on your truck before ordering.
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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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