Description
The World American WA01-9621C is a rolling-lobe trailer air spring for Hendrickson INTRAAX AA230L suspensions, replacing Firestone 9621 / W01-358-9621 and Hendrickson S-23613 / C-23613. 24.7″ extended / 7.4″ compressed height with a 12.2″ max diameter; 9.0″ two-bolt top plate (3306) on 5.5″ centers and a single-stud 10.31″ piston (9532) for OE-style bolt-in fit on dry van, reefer, flatbed, and heavy-haul trailers.
Signs You Need a New Trailer Air Spring
- Trailer sagging or sitting unevenly when loaded
- Visible cracks, dry rot, or weather-checking on the bellows
- Air leaks — system can’t hold or build to ride height
- Excessive trailer bounce or “hop” when running empty
- Uneven tire wear from suspension imbalance side-to-side
Specifications
| Manufacturer | World American |
|---|---|
| Part Number | WA01-9621C |
| Part Type | Rolling Lobe Air Spring (Trailer) |
| Extended Height | 24.70 in |
| Compressed Height | 7.40 in |
| Maximum Diameter | 12.20 in |
| Top Plate Number | 3306 |
| Top Plate Diameter | 9.00 in |
| Top Plate Holes | 2 (5.50 in center-to-center) |
| Piston Number | 9532 |
| Piston Diameter | 10.31 in |
| Piston Holes | 1 |
| Warranty | 1 year / 100,000 miles |
Cross References
This air spring replaces or is equivalent to the following part numbers:
- Firestone: 9621, W01-358-9621, 1T15LB-10
- Hendrickson: S-23613, C-23613
- ContiTech: 64696, 9 9B-20 P 740, AS9621
- Dayton: 352-9621
- Meritor: FS9621
- Euclid: E-FS9621
- Paccar: AS96210
- HD Value: HDV9621
- Torque: TR9621
Applications
This air spring fits Hendrickson INTRAAX trailer suspensions on:
- Hendrickson INTRAAX AA230L suspension series
- Wabash, Utility, Great Dane, Hyundai Translead, and Vanguard trailers spec’d with Hendrickson INTRAAX
- Dry van, refrigerated (reefer), and flatbed trailers
Verify your suspension model, ride-height setting, and exact piston / top-plate hardware before ordering — INTRAAX variants and other Hendrickson trailer suspensions use different envelopes.
