20505399 | S&S Truck / Newstar Air Spring | 1R12-405 / 1R12-595, S-22540 | New Aftermarket

New Aftermarket S&S Truck / Newstar 20505399 (New Aftermarket Replacement) — heavy-duty rear suspension air spring assembly engineered to maintain proper ride height, load support, and suspension performance in compatible Volvo and Mack truck applications. Cross-referenced with Firestone 1R12-405, 1R12-595, W01-358-8829, FS8829, and Newstar S-22540.

In stock and ready to ship from Discount Parts Exchange (DPX) in Mansfield, Ohio.

Call to confirm availability: 419-522-3320

Key Specifications

• Part Number: 20505399
• Manufacturer: S&S Truck / Newstar
• Type / Model: Heavy-Duty Air Spring Assembly
• System: Rear Air Suspension
• Function: Supports vehicle load, maintains ride height, and helps absorb road shock in compatible air suspension systems
• Condition: New Aftermarket Replacement
• Warranty: Sold As-Is, No Warranty
• Alternate Part Numbers: 1R12-405, 1R12-595, W01-358-8829, FS8829, S-22540
• Top Plate Mount: (2) Studs
• Bottom Plate Mount: (1) Stud
• Extended Height: Approx. 22"

Applications & Fitment

Fits select Volvo and Mack rear air suspension systems requiring air spring 20505399, Newstar S-22540, or matching Firestone-style cross-reference numbers.

• Volvo rear air suspension systems
• Mack rear air suspension systems
• Select Volvo VN and VNL truck models
• Heavy-duty truck suspension replacement applications

Important: Always verify part number, mount configuration, air spring dimensions, suspension position, and system compatibility before ordering or installation.

What’s Included

• 1 × S&S Truck / Newstar Air Spring – 20505399 / S-22540
• Aftermarket air spring assembly as supplied
• Mounting hardware / fittings not included unless noted

DPX Drivetrain Tools Hub

Free tools built by rebuilders for mechanics, drivers, and fleets:

Road Speed Calculator • Gear Ratio Charts • PTO Shimming Guide • Full IPL Library →

Shipping / Location

• Ships from our Mansfield, Ohio warehouse (419-522-3320)
• Parcel shipping available
• Warehouse Bin Location: DPX_OH_BR549_SUSP

Heavy-Duty Solutions — Built to Perform. Trusted to Last. Discount Parts Exchange (DPX).