Frequently Asked Questions About Diesel Camshafts & Valve Train Parts
What valve train components does Highway and Heavy Parts carry?
Highway and Heavy Parts offers a comprehensive selection of diesel valve train components for all major manufacturers including camshafts (new and remanufactured options) for precise valve timing, rocker arms and rocker arm assemblies for valve actuation, push rods and push tubes for overhead valve engines, cam followers and lifters that ride on the camshaft lobes, rocker shafts and pivot points for rocker arm operation, valve springs and retainers to control valve closure, crossheads and crosshead guides for specific engine designs, rocker arm pin and roller kits for cost-effective repairs, and complete valve train rebuild kits. All components are available for Cummins, Caterpillar, Detroit Diesel, Mack, Volvo, International/Navistar, and other major diesel engines.
What are common symptoms of camshaft or valve train failure?
Common signs of valve train failure include ticking, clicking, or tapping noises from the cylinder head that increase with engine RPM, loss of engine power or poor acceleration indicating improper valve timing, rough idle or engine misfires from valves not opening or closing properly, popping or backfiring in the intake manifold or exhaust system, excessive valve lash or clearance during adjustments, poor fuel economy due to inefficient combustion from valve timing issues, and metal shavings in the oil from worn cam lobes or followers. If you experience any of these symptoms, inspect your valve train components immediately as continued operation can cause catastrophic engine damage requiring complete rebuild.
Should I choose a new or remanufactured camshaft for my diesel engine?
A new camshaft offers several advantages including brand new forged billet steel construction with no previous wear history, engineered to exceed OEM specifications for lobe profile and lift, superior hardness rating of 55RC or higher for extended wear resistance, no core charge required since it’s a complete new part, and maximum reliability for critical applications where dependable operation is essential. Remanufactured camshafts provide good value with professionally rebuilt cores, proper hardness restoration, and significantly lower cost, making them suitable for budget-conscious repairs. However, new camshafts ensure the longest service life and peak performance restoration, particularly important for high-mileage engines or those operating in demanding commercial applications.
Why do I need to replace other valve train components when installing a new camshaft?
When replacing a camshaft, you must also replace components that directly contact the cam lobes because if there is wear on the camshaft lobes, the cam followers or rollers in your rocker arms also have corresponding wear patterns and will cause premature failure of the new camshaft if not replaced. Installing a new camshaft against worn followers creates mismatched wear patterns that accelerate camshaft lobe failure. Most professional mechanics recommend replacing cam followers, rocker arm rollers, push rods, and valve springs when installing a new camshaft to ensure proper break-in, prevent premature wear, and maximize the service life of your valve train investment.
Can I replace just the rocker arm roller instead of the entire rocker arm assembly?
Yes! For several engine applications, Highway and Heavy Parts offers pin and roller kits that allow you to replace just the worn roller component instead of the entire rocker arm assembly, potentially saving thousands of dollars on valve train repairs. While many OEMs only sell complete rocker arm assemblies, there is no reason to replace the entire unit if only the roller is worn. Purchasing individual pin and roller kits is significantly cheaper than complete rocker arms, and when multiplied by the eighteen or more rocker arms that some engines have, the cost savings increase tremendously while maintaining the same quality and performance standards.
How does valve train timing affect diesel engine performance?
The valve train controls incredibly precise timing for air intake, exhaust evacuation, and fuel injection in diesel engines. The camshaft lobes create an upward force on rocker arms, which push valves down at exact intervals coordinated with piston position and crankshaft rotation. Proper valve timing ensures maximum cylinder filling during intake, complete exhaust evacuation, and optimal compression for efficient combustion. When valve train components wear and develop excessive clearance or tolerance, valve timing becomes imprecise, causing loss of power, poor fuel economy, rough operation, and potential engine damage from valve-to-piston contact or incomplete combustion.
What causes valve train noise and ticking in diesel engines?
Valve train ticking or tapping noise occurs when worn components create excessive clearance between parts that should maintain tight tolerances. The nominal setting might be 27 thousandths of an inch between the rocker lever and crosshead, but when components wear, this tolerance increases and creates audible ticking as metal parts impact each other with greater force and distance. Common causes include worn cam follower pins or rollers that increase clearance, worn crosshead sockets where push tubes rest, damaged or bent push tubes, worn rocker arm pivot points, and excessive valve lash from worn valve stem tips or seats. Diagnosing requires systematic valve lash adjustment and component inspection to identify which parts have excessive wear.
What support does HHP provide for valve train installation and diagnosis?
Highway and Heavy Parts employs ASE-certified diesel technicians with specialized expertise in valve train systems who provide comprehensive support including detailed installation guidance with proper torque specifications and timing procedures, diagnostic troubleshooting to identify root causes of valve train failure, compatibility verification for your specific engine application and CPL number, comprehensive technical documentation with timing specification charts and adjustment procedures, and post-installation support if issues arise. Orders placed by 2PM EST ship same day Monday through Friday from HHP’s Coleman, Michigan facility stocking over 250,000 diesel parts. All valve train components are backed by HHP’s standard 1-year unlimited mileage warranty with select parts eligible for extended coverage.
