Regular rocker arm maintenance is as critical as running a leak-down test, setting lash, checking spring pressure, or changing oil. Overlooking rocker arm inspection can lead to costly issues over time.
At T&D Machine, we frequently receive calls from customers wanting to replace all the bearings in their rocker arms. While we can provide any components needed, we caution against replacing bearings without proper diagnosis. Because T&D rocker arms are internally oiled, bearing failures are extremely rare. If a bearing feels rough or damaged, it is usually a symptom of another underlying problem.
Common Causes of Rocker Arm Wear
When a bearing issue arises, the first question is whether the engine has experienced trauma such as a blow-up, broken valve spring, valve-to-piston contact, or over-rev. In these events, the rocker arm can experience extreme forces as the pushrod attempts to open a valve being slammed shut by the piston.
Even if the pushrod remains straight, the bearing bore in the rocker body can become slightly oval instead of perfectly round. Installing new bearings in an out-of-round bore will not solve the issue; once the engine runs, the new bearings will quickly conform to the distorted shape, recreating the same problem.
Oil Quality and Rocker Arm Lubrication
If no mechanical damage is evident, the next step in rocker arm maintenance is evaluating oil quality and delivery. Insufficient or poor-quality oil compromises the protective film required to prevent metal-to-metal contact within the rocker arm. Without proper lubrication, premature wear occurs in bearings and tips.
T&D rocker arms rely on oil routed through the pushrod for internal lubrication. Because of this, adjuster screw position is critical. If the adjuster is set too deep or the pushrod is too short, the rocker arm may be starved for oil. While the adjuster may appear unaffected, the bearings and roller tips will show accelerated wear from inadequate lubrication.
Professional Rocker Arm Inspection and Rebuild Service
T&D offers a complete rocker arm inspection and rebuild service. Customers can send in their rocker assemblies for full evaluation and cleaning. Each rocker is disassembled, inspected under magnification, and checked for galling, pitting, or bearing bore distortion.
The bearing bore is honed perfectly round when manufactured. Over time, or after mechanical stress, the aluminum housing can stretch, causing the bore to become oval. In severe cases, the bearings can lose press fit and shift within the body during operation.
We do not recommend attempting to re-hone an out-of-round rocker, nor do we recommend using adhesives like Loctite to secure bearings. Once the aluminum material has stretched, the rocker body must be replaced to maintain reliability and proper rocker arm performance.
Recommended Rocker Arm Maintenance Intervals
For preventative rocker arm maintenance, we suggest sending rockers for inspection whenever the engine is freshened or after any valvetrain-related issue. This ensures early detection of wear and prevents catastrophic failures.
The best time to schedule rocker inspection is at the end of race season, giving sufficient lead time before the next cycle. Turnaround times vary based on workload, so early submission is ideal.
During rebuilds, customers can also upgrade to additional T&D performance features such as the spring oil hole option or needle bearing tips while the rockers are already disassembled.
Summary
Consistent rocker arm maintenance is essential for preserving valvetrain integrity and maximizing engine performance. Proper lubrication, regular inspections, and early detection of structural distortion can prevent failures and extend rocker arm lifespan. For complete inspection and rebuild services, contact T&D Machine to keep your rocker arms performing at peak reliability.