How to Replace a Bent Pushrodby Tom Price
A bent pushrod can not only affect your engine's performance, it can seriously damage other parts if the problem is not taken care of immediately. The reason being that if a pushrod is severely bent or it breaks, the pushrod could dislodge itself from between the valve lifter and the rocker arm and fall through the engine into the oil pan. It is not enough to just replace the pushrod. A technician must also diagnose why the pushrod bent in the first place.
Remove the valve cover on the affected bank of the engine.
Wiggle all of the pushrods to determine which rod or rods are bent and mark the rod with a yellow wax marker.
Remove the rocker arm by removing the rocker arm nut over the bent pushrod -- if the vehicle is equipped with individual rocker arms. If the engine is equipped with a rocker shaft, remove the rocker shaft assembly by loosening the bolts that are attaching it to the head. Use a ratchet wrench and the appropriate size socket for the nuts or bolts being removed.
Remove the bent pushrod by pulling it up through the cylinder head by hand and set it aside. Inspect all of the other pushrods for wear or cracking if the motor is equipped with a rocker shaft assembly. If there is severe damage on one cylinder bank it is prudent to inspect the other bank for damage.
Inspect the rocker shaft and all of the rocker arms and springs on the shaft for damage and replace any worn or broken parts, as necessary.
Inspect the valve springs for breakage or damage. Inspect the visible portion of the valve shaft to ensure that they are straight and not excessively worn down.
Install a new pushrod in place of the bent one and reinstall the other pushrods by placing them through the cylinder head by hand, making sure that they all seat in the valve lifter. Reinstall either the rocker shaft assembly or the rocker arm making sure that all of the pushrods remain seated in both the valve lifters and rocker arms or shaft.
Start the engine and adjust the valves if not equipped with a rocker shaft. Observe the operation of the rocker arms and pushrods to ensure that they are working properly.
Replace the valve cover and valve cover gasket. Clean all oil off the engine compartment.
Test drive the vehicle to ensure that there are no further problems. Check the valve covers for leaks.