Frequently Asked Questions About Peterbilt 330/335/337 Air Springs & Level Valves
Will these air springs fit my specific year model Peterbilt 330, 335, or 337?
Most air springs and level valves for these models are compatible across years 2005-2021, but there are important variations. The 330 and 335 models typically share the same suspension components, while the 337 may have different specifications depending on GVWR configuration. Always verify your truck's OEM and suspension type (Hendrickson, Reyco, or other) before ordering. If you're unsure, check the part number on your existing air spring or contact us with your OEM for exact fitment verification.
What's the difference between rubber and aluminum top plate air springs, and which should I choose?
Rubber top plate air springs are the standard OEM choice and work well for most applications, typically lasting 3-5 years under normal use. Aluminum top plate versions offer enhanced durability and better resistance to road chemicals and salt, making them ideal for trucks operating in harsh winter conditions or coastal areas. While aluminum plates cost about 20-30% more initially, they often outlast rubber plates by 2-3 years. Choose rubber for standard applications or aluminum if you need maximum longevity.
Can I replace just one air spring, or do I need to replace them in pairs?
While it's technically possible to replace a single air spring, we strongly recommend replacing them in pairs per axle. Mismatched air springs can cause uneven ride height, premature wear on the new spring, and potential handling issues. If one spring has failed, the opposite side has likely experienced similar wear and stress. Replacing in pairs ensures balanced performance and typically costs less than making two separate repairs down the road.
What tools and skills are needed to install air springs and level valves myself?
Basic installation requires jack stands rated for commercial trucks, a floor jack, basic hand tools, and ideally an impact wrench. The job typically takes 2-3 hours per axle for experienced DIYers. Key challenges include safely supporting the truck's weight, removibng corroded bolts, and properly adjusting the level valve linkage. You'll need to measure ride height accurately and may need to adjust the level valve arm angle. If you're not comfortable working with air systems or lack proper lifting equipment, professional installation is recommended for safety.
How do I know if my level valve is bad versus just needing adjustment?
A properly functioning level valve should maintain consistent ride height and respond quickly to load changes. Signs of a bad valve include: truck leaning to one side, constant air bleeding, slow height recovery after loading, or failure to maintain height overnight. Before replacing, try adjusting the linkage arm - many issues are simply misalignment. To test, manually move the valve arm up and down; you should hear air entering or exhausting the springs. If the valve doesn't respond or leaks internally, replacement is necessary. Always check air lines and fittings first, as leaks there can mimic valve problems.
