Frequently Asked Questions About Kenworth W990 Steer Axle Springs & Hangers

What are the weight capacity ratings for W990 steer axle springs, and how do I choose the right one for my truck?

Kenworth W990 steer axle springs typically come in 12,000 lb, 13,200 lb, and 14,600 lb capacities. To select the correct capacity, check your door jamb sticker for the front GAWR (Gross Axle Weight Rating) or consult your owner's manual. For heavy-haul applications or if you frequently carry maximum loads, consider upgrading to a higher capacity spring. Remember that both springs on the axle should always be replaced as a matched set to maintain proper ride height and handling.

Will these springs and hangers fit my specific year W990, and are there differences between model years?

The W990 has maintained consistent steer axle specifications since its introduction in 2018. Springs and hangers designed for the W990 will fit all model years from 2018 to present. However, always verify the spring eye dimensions (typically 3-inch front eye and 3-inch rear eye) and center-to-center measurements before ordering. Some W990s with specialized front suspensions or heavy-haul configurations may require different specifications.

Can I install these springs and hangers myself, or do I need special tools?

While experienced mechanics can perform this installation, it requires heavy-duty tools including a spring compressor, torque wrench capable of 450-500 ft-lbs, and proper jack stands rated for commercial trucks. The job typically takes 4-6 hours per side. Critical safety steps include properly supporting the axle, compressing springs safely, and torquing U-bolts to specification in the correct sequence. Many customers choose professional installation due to safety concerns and the need for front-end alignment afterward.

What's the difference between OEM and aftermarket springs, and which should I choose?

OEM springs are manufactured to Kenworth's exact specifications and typically feature shot-peened leaves for longer life and consistent spring rates. Aftermarket options from reputable manufacturers like Dayton Parts or Triangle Spring often provide comparable quality at 20-30% less cost. Look for springs with military-wrapped eyes, diamond-cut center bolts, and zinc phosphate coating for corrosion resistance. Avoid budget springs that lack these features, as they may sag prematurely or develop cracks.

How often should I inspect and replace hangers, bushings, and shackles?

Inspect hangers and bushings every 50,000 miles or during regular PM services. Look for cracks in hanger brackets, worn or collapsed bushings, and excessive play in shackle pins. Replace bushings when you see metal-to-metal contact or more than 1/8-inch of play. Hangers typically last the life of the truck unless damaged, but bushings usually need replacement every 200,000-300,000 miles depending on application. Always replace bushings and shackle pins when installing new springs to ensure proper articulation and prevent premature wear.