What Are Push Rods and What Do They Do?
Alright, let's talk push rods. These aren't the flashy parts you see advertised everywhere, but they're absolutely crucial for your engine's breathing. In a nutshell, push rods are long, hollow tubes that sit between the rocker arms and the lifters in many overhead valve (OHV) engines. When the camshaft lobe pushes up on a lifter, the lifter pushes up on the bottom of the push rod. That push rod then travels up its tube to push down on the rocker arm, which in turn opens the engine's intake or exhaust valve. They're a vital link in the chain that gets air and fuel into your cylinders and exhaust out. Simple, right? But crucial.
Common Signs of Push Rod Failure
Push rods themselves don't fail very often in a catastrophic way. They're pretty robust. More often, you'll see symptoms that indicate a problem *related* to the push rods or the components they interact with. The most common issue you might encounter is a bent or worn push rod. If a push rod gets bent, perhaps from a valve spring failure or a piston-to-valve collision (don't ask), it won't transmit the lift from the lifter to the rocker arm correctly. This can lead to:
- Reduced engine power: A valve not opening fully or at the right time means poor cylinder filling and exhaust scavenging.
- Engine misfires: If a push rod is significantly bent or broken, a valve might not open at all, causing a dead cylinder.
- Ticking or tapping noises from the engine: A bent push rod or excessive wear at the ends where it contacts the lifter and rocker arm can create noise. It's often a rhythmic tick that speeds up with engine RPM.
- Difficulty starting or rough idling: Similar to power loss, improper valve timing or lift will make the engine run poorly.
Often, these symptoms point to a broader issue in the valvetrain, and inspecting the push rods is part of diagnosing that issue.
Used OEM vs. Cheap Aftermarket: The Verdict
For push rods, a properly inspected used OEM part is almost always the safer, more reliable choice than a cheap, no-name aftermarket copy. Why? OEM parts are manufactured to the original equipment manufacturer's specifications. They're made from materials and with tolerances that the engineers designed the engine around. Cheap aftermarket parts, especially ones you find for just a few bucks, often cut corners. They might use weaker metals, have imprecise dimensions, or lack the proper heat treatment. This can lead to premature bending, wear, or even failure, potentially causing more expensive damage to your lifters and rocker arms. An OEM part, even if used, has already survived its initial break-in period and proven its durability. If it's been inspected and looks good, it's likely got plenty of life left and will perform as intended.
What to Check Before Buying
Whether you're looking at a used OEM push rod or considering an aftermarket option (though I'd strongly advise against the cheapest ones), here's what you need to check:
- Straightness: Lay the push rod on a flat surface. Any deviation or wobble means it's bent and useless.
- Ends: Inspect both the top and bottom ends. They should be smooth, without excessive pitting, mushrooming, or wear. The ball end (if applicable) and the cup end should be intact.
- Straightness (again, it's that important): Hold it up and sight down its length. Look for any subtle bends that might not be obvious on a flat surface.
- Integrity: Check for any cracks or signs of stress, especially near the ends. If it's a hollow push rod, ensure there are no holes or damage to the tube itself.
Don't just grab the cheapest option. Your engine's valvetrain deserves better. A good used OEM push rod, checked carefully, will serve you far better than a flimsy aftermarket replacement.
Browse our selection of properly inspected used OEM push rods to find the right fit for your vehicle.
