How do you adjust valve lash hydraulic lifters?
Loosen the adjusting nut slightly until lash can be felt in the rocker arm. While spinning the pushrod with your fingers tighten the adjusting nut—when a slight resistance is felt the valve is at zero lash, or the point where all the slack is removed.
What is excessive valve lash?
Valve Lash or Valve Clearance is the gap between the Rocker Arms and the valve tappet. This clearance must be tightly controlled. If it is too little, the valves may not seat properly. If you have too much valve lash, you eliminate the more “gentle” sections and are basically “slamming” the valve open and closed.
How often should valve lash be checked?
On a shaft-mount system, most manufacturers say lash should be checked every 500 to 700 laps. Once you’ve determined that the valve you are checking is fully closed, actually checking the lash is the easy part. Simply use a feeler gauge and slide the tab of the correct thickness between the tip of the valve stem and the end of the rocker.
What causes valve lash?
What is a cause for concern is if you notice the valve lash opening up. The most common reason for this is a failure of the needle bearings in a roller lifter or a wiped cam lobe. “Wiping” a cam is when a lack of lubrication or some other problem causes the crown of the lobe of the cam to be ground away.
Why is valve lash necessary?
Valve lash is intended to provide the greatest amount of valve opening on the high point of the camshaft lobe and assure that the valve is tightly closed on the low segment of the camshaft lobe. Valve lash adjustment is necessary maintenance for engines without hydraulic valve lifters.
What is a valve lash adjustment?
RAY: A “valve lash adjustment” is just another term for a valve adjustment, Cynthia. And it’s required on all cars that have adjustable valves. There are fewer and fewer cars that fall into this category, but yours happens to be one of them. TOM: The “valve lash” is the space between the valve stem and the rocker arm.