Pay in 4 interest-free payments of $30.00 Learn more
Ships within 48 hours · Estimated delivery Sep 15 - Sep 20
and ships with the cartridge plus the required seal package
Fits both Big Cam and Small Cam 855 configurations
Verify your Allison transmission model and serial number before ordering to confirm fitment
Western Star 4900 / 5700 / 4700 (Eaton-spec)
World American WA01-9978C Air Spring | Replaces Mack 8446-S28929 Filtration and ships with the cartridgeThe 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
