Frequently Asked Questions About Kenworth W900B/W900L Cab, Sleeper & Cowl Panels

What's the difference between aftermarket and OEM panels, and how does it affect fit and quality?

Aftermarket panels vary significantly in quality. Premium aftermarket panels use 16-18 gauge steel similar to OEM specifications and feature proper stamping for exact fitment. Lower-quality options may use thinner 20-22 gauge steel that can dent easily and require extensive modification during installation. OEM panels guarantee perfect fit but cost 40-60% more. We recommend checking the steel gauge and looking for panels with pre-drilled mounting holes that match factory specifications to avoid fitment issues.

Will these panels fit both W900B and W900L models, and what years are compatible?

While W900B (1987-2004) and W900L (1987-present) share many components, not all panels are interchangeable. The main difference is the hood length - W900L has a longer hood requiring different cowl panels. Cab back panels and sleeper panels typically fit both models within the same year ranges. Major design changes occurred in 2005 with the introduction of the aerodynamic package, so panels are generally categorized as pre-2005 or 2005-newer. Always verify your specific VIN and build date, as mid-year production changes can affect compatibility.

What tools and skills are needed for installation, and should I hire a professional?

Basic panel replacement requires a drill, rivet gun, grinder, and standard hand tools. Most installations take 4-8 hours per panel for experienced mechanics. Critical areas like cab corners often require welding for proper structural integrity. Common challenges include removing old panels without damaging surrounding components, properly aligning new panels, and addressing hidden rust damage. Professional installation typically costs $150-300 per panel but ensures proper fitment and paint prep. DIY installation is feasible for bolt-on panels, but welded sections should be handled by professionals to maintain cab structural integrity.

Do these panels come primed or painted, and what prep work is required?

Most replacement panels come with a black e-coat primer that prevents rust during shipping but requires additional preparation before painting. This primer must be scuffed with 320-400 grit sandpaper and cleaned before applying automotive primer and paint. Some premium panels feature a gray primer that's paint-ready, saving prep time. Raw steel panels require immediate treatment to prevent rust. Plan for additional costs: professional painting typically runs $200-400 per panel including prep work, primer, base coat, and clear coat to match your existing finish.

Which panels are most prone to rust and should be replaced first?

Based on common wear patterns, prioritize these areas: (1) Lower cab corners where road spray accumulates, (2) Sleeper-to-cab transition panels where water can pool, (3) Lower door jamb areas exposed to driver entry/exit wear, (4) Cowl panels near the windshield where leaves and debris trap moisture. Battery box areas and step panels also deteriorate quickly due to acid and salt exposure. When inspecting for replacement needs, check behind insulation and sound deadening material where rust often hides. Addressing these high-risk areas first prevents rust from spreading to adjacent panels and maintains structural integrity.