Description
The World American WA01-9978C is a heavy-duty rolling lobe air spring engineered for trailer suspensions. Designed as a direct replacement for Mack 8446-S28929, this OEM-equivalent spring delivers consistent height control, superior durability, and reliable damping for long-haul and vocational trailers. Built to withstand harsh road conditions and heavy loads on highways and back roads.
Specifications
| Category | Air Springs / Air Bags |
|---|---|
| Part Type | Trailer (tandem or tri-axle) |
| Design Style | Rolling Lobe |
| Bottom Plate Alignment | Parallel |
| Bottom Plate Diameter | 10.24 inches |
| Bottom Plate Center-to-Center | 2.25 inches |
| Bottom Plate Hole Quantity | 1 |
| Maximum Diameter | 12.6 inches |
| Minimum Height | 7.8 inches |
| Warranty | 3 years |
Cross References
This part replaces or is equivalent to the following part numbers:
- Mack: 8446-S28929
- Continental-ContiTech: 67588, 910-14P959
- Dayton Parts: 352-9978
- Euclid: E-FS9978
- Firestone: W01-358-9978, 9978
- Goodyear: 1R12-668
- Hendrickson: C28929, S-28929
- Holland: G2299978200
- Meritor: FS9978
- PACCAR Parts: AS99780
- Triangle Air Springs: AS-9978
Applications
This rolling lobe air spring is used on trailers with:
- Tandem axle suspensions (rear axles)
- Tri-axle suspensions
- Over-the-road semi-trailers
- Chassis and drop-deck trailers
- Refrigerated and flatbed trailers
Verify trailer suspension type and axle configuration before ordering to ensure correct fitment.
