Air Spring | Hendrickson S-28929 / C-28929 ~ Goodyear 1R12-668 ~ Firestone W01-358-9978 | FleetRun FR-SPSN501


Same Day Shipping

Order The Truck Parts You Need Now and Pay Later With Our Financing Option Available

Order Now, Pay Later

Need Help With Parts?

(872) 240-4144

Hassle Free Returns

6 Month / 50,000 Mile Warranty

Part Number

  • FleetRun: FR-SPSN501

Cross Reference Part Number

  • Hendrickson: S-28929 / C-28929 / B-28929 / 28929 / C28929
  • Goodyear: 1R12-668
  • Firestone:  W01-358-9978
  • Torque: TR9978
  • Meritor: FS9978
  • Euclid: E-FS9978
  • Automann: 1DK23I-A959
  • TRP: AS9978
  • Misc. Industry Part Number: TDAMAF9978 / SP 559978-KP / G2299978200 / GYR1R12668 / GYR-1R12-668


    • Top Plate Hole/Stud Quantity: 2
    • Bottom Plate Hole/Stud Quantity: 1
    • Extended Height: 19.60 in.
    • Compressed Height: 7.80 in.
    • Top Plate Diameter: 9.00 in.
    • Bottom Plate Diameter: 10.25 in.
    • Top Plate Studs Center To Center: 5.50 in.
    • Top Stud(s) Outer Thread: 3.4-16 UNF
    • Top Stud(s) Inner Thread: 1/4-18 NPTF
    • Bottom Stud Thread: 1/2-13 UNC

    Please note: this is an aftermarket part, the use of other manufacturer's names, part numbers or trademarks is for informational purposes only.

    Please verify OEM part numbers before purchasing, FleetRun assumes no liability related to product use and fitment.

    Looking for a reliable and high-quality air spring for your truck, trailer, or dolly? Look no further than FleetRun's FR-SPSN501, the perfect solution for all your air suspension needs. With a cross-reference part number of S-28929, W01-358-9978 and TR9978, you can rest assured that this air spring is compatible with Hendrickson air suspension systems. Additionally, it's cross-compatible with Goodyear 1R12-668 air springs.

    Our FR-SPSN501 air spring also meets or exceeds OEM standards and is designed to provide excellent ride quality while being durable and long-lasting. It features two top plate holes/studs and one bottom plate hole/stud with an extended height of 19.60 inches and a compressed height of 7.80 inches. The top plate diameter is 10.38 inches, and the bottom plate diameter is 10.25 inches, with top plate studs center to center of 5.50 inches.

    If you're experiencing any issues with your air suspension system, visit our Shop Talk page or FAQs below for helpful tips and troubleshooting from our expert technicians.

    Don't let air suspension issues slow you down. Order FleetRun's FR-SPSN501 air spring today and experience the difference in ride quality and durability.

    • For other information such as tips and tricks or troubleshooting from technicians and shops visit our Shop Talk page from our menu

    Trailer air bags not inflating

    Most common problems for this issue are:

    • Major air leak on the tandem (an air spring, a relay valve or other valve, air lines not connected or damaged)
    • A failed or malfunctioning heigh control valve

    How do you fix an air bag leak?

    • You don't, air springs that have failed need to be replaced, they are not repairable. If the air leak is compromising your safety you can pinch off or plug the air line for the leaking air spring in order to pull over safely, but this can be very dangerous as well.