What This Air Spring Is
This is a rolling-lobe, reversible-sleeve air spring for the trailer axle. The bellows rolls down over a composite plastic piston instead of a metal one, so the piston will not rust through at the road-spray line the way steel pistons do on salted winter routes. That matters on trailers that sit loaded in yards for weeks at a time.
Dimensions are 14.0 inches extended, 4.7 inches collapsed, roughly 10.4 inches at maximum diameter, and about 13 pounds. Those figures are the quickest way to confirm you are looking at the same bag family. If the old unit measures noticeably taller or shorter at full droop, you are on a different spring and the cross-reference stops there.
The application is the primary trailer-axle air spring on Meritor 202796 and Ridewell-Neway style heavy-duty trailer air suspensions, including Utility Trailer builds. It is an aftermarket part, not a factory-supplied one. Other manufacturers' numbers appear here for identification only.
Why These Numbers Cross
The suspension builder specifies the bag, then the bag maker assigns its own part number, and the trailer OEM assigns a third. Same physical spring, three separate catalogs. That is why W01-358-8729 shows up as Goodyear 1R13-130 and 566-26-3-055, ContiTech 10 10.5AV-12 and 64420, and Meritor 202796 on the suspension parts list.
The trailer-side numbers work the same way. Neway lists G2298729200, Paccar carries RL87290, and Utility Trailer uses AGA8729 on its own build sheets. Each is a stocking number pointing at one bellows with one bead plate configuration, one piston, and one set of mounting hardware locations.
Cross-reference gets you to the right family. It does not guarantee your trailer left the plant with that suspension, and it does not account for a previous owner swapping in something else. Confirm by VIN, by the suspension tag, or by the number stamped on the bag you are pulling off.
Checks Before You Order
Find the suspension model tag on the hanger or crossmember first. If it is painted over or gone, get the ride height and measure the bag at ride height with the trailer level and the system aired up. Then dump the air and check collapsed height. Those two numbers plus the piston material tell you most of what you need.
Look at the failure before you replace. A bag that chafes a hole in the sleeve usually has a bent piston, a loose shock, or debris riding on the piston shoulder. Fix that or the new spring fails the same way. Replace both bags on an axle so ride height stays even, and check the height control valve linkage while the trailer is in the air.
W01-358-8729 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-8729. 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 | 10 10.5AV-12, 64420 |
| Goodyear | 1R13-130, 566-26-3-055 |
| Meritor | 202796 |
| Neway | G2298729200 |
| Paccar | RL87290 |
| Utility Trailer | AGA8729 |
Frequently asked questions
How do I know if my trailer uses the Meritor 202796 suspension?
Check the tag on the suspension hanger or the trailer's build sheet. If the tag is unreadable, pull the old air spring and read the number molded or stamped into the bead plate. Matching that number against the cross-reference list is more reliable than guessing from the trailer make. Fit is confirmed by VIN or by the number on the old part.
Do I have to replace both air springs on the axle?
Replace in pairs on the same axle. A new bag next to an old, fatigued one gives uneven ride height and loads the height control valve into constant correction. That accelerates wear on the remaining original. If the second bag is more than a couple of years old, do both while the trailer is already in the air.
Why does the plastic piston matter?
The composite piston will not corrode. Steel pistons pit at the spray line, and the rough surface abrades the bellows sleeve from the inside as the lobe rolls. That shows up as a slow leak or a blowout well before the bag's normal service life. Check the old piston for pitting or a bent lip before installing the new spring.
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.