Description
Genuine Firestone W01-358-9966 is a reversible-sleeve Airide air spring originally engineered for Reyco Granning 240AR air suspensions and shipped from the factory on Spartan motorhome chassis (Mountain Master, K2-K4 series), Class A diesel pushers, motor coaches, and heavy-duty trucks running Reyco air-ride. As the OEM, Firestone delivers the bellows construction, piston tuning, and top-plate geometry the suspension was originally certified to.
Signs You Need a New Air Spring
- Vehicle sagging or leaning to one side at rest
- Rough or bouncy ride that doesn’t settle at speed
- Visible cracks, dry rot, or scuffing on the bellows
- Air leaks or inability to maintain ride height overnight
- Uneven tire wear caused by suspension imbalance
Specifications
| Manufacturer | Firestone (Genuine OEM) |
|---|---|
| Part Number | W01-358-9966 |
| Part Type | Reversible Sleeve Air Spring |
| Bellows Number | 1T15M-6 |
| Extended Height | 20.50 in |
| Compressed Height | 7.20 in |
| Top Plate Number | 3310 (9.00 in dia.) |
| Piston Number | 9583 (10.00 in dia., aluminum) |
| Bracket | 6030 |
| Warranty | 2 year / 200,000 mile (Firestone) |
Cross References
This part replaces or is equivalent to the following part numbers:
- Firestone: 9966, W013589966, W01-755-9966
- Reyco Granning: 20124-01, 20124-01A, 20124-01K, 20124-02, 20124-12
- Spartan: 1919-DD4-001
- ContiTech: 64668, 9 10-17.5 P 731
- Automann: AB1DK23P-9966
- Dayton: 352-9966
- Meritor: FS9966
- SAF Holland: G2299966200
- World American: WA01-9966C
Applications
This air spring fits Reyco Granning 240AR air suspensions found in:
- Spartan motorhome chassis (Mountain Master, K2, K3, K4 series)
- Class A diesel pusher motorhomes
- Commercial buses with Reyco 240AR suspension
- Heavy-duty trucks with Reyco Granning air ride systems
Air Inlet Note: The Reyco 20124-02 version uses 1/2 in NPT air inlet. Reyco 20124-01 and 20124-01K use 1/4 in NPT. A 1/2 in to 1/4 in adapter may be required depending on your specific application.
Verify your suspension model and air-inlet thread before ordering to confirm fitment.
