Jeep 4621938 Valve Tappet

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Before removing the camshafts, you have to take them off; after doing so, you can also take out the rocker arms. Losing hold of the rocker arms and valve lash adjuster that were removed should be avoided, thus it is advisable to mark each out individually to know which one goes where. Before installing use the opportunity to check the rocker arm tip, roller, and lash adjuster pocket for signs of wear; if any replace them. Each should be inspected in detail but particularly the ball-end which rubs against the rocker arm as these are prone to becoming obstructed; if there is doubt about their condition or if the engine develops 'valve-tapping' it will be wise to replace them. Prior to fitting the lash adjusters should be partly filled with engine oil and it should be noted that when the plunger is depressed, the movement should be minimal. And if there is too much of this travel increase, immerse the rocker arm assembly in clean engine oil and pump the plunger until such travel is nudged out. When filled with oil the Plunger has to move within the rocker arm, if so then the Plunger is defected and has to be replaced. Bolt the hydraulic lash adjusters and rocker arms to their standard position in the cylinder head and then replaced the camshafts. The adjusters should make 'tapping' noises in the initial times after restarting the engine after replacement. The process is to keep increasing the engine speed reiteratively from idle to 3000 rpm and back to idle for one minute; if the adjusters are noisy, as they should be, they will have to be replaced.

Before removing the camshafts, you have to take them off; after doing so, you can also take out the rocker arms. Losing hold of the rocker arms and valve lash adjuster that were removed should be avoided, thus it is advisable to mark each out individually to know which one goes where. Before installing use the opportunity to check the rocker arm tip, roller, and lash adjuster pocket for signs of wear; if any replace them. Each should be inspected in detail but particularly the ball-end which rubs against the rocker arm as these are prone to becoming obstructed; if there is doubt about their condition or if the engine develops 'valve-tapping' it will be wise to replace them. Prior to fitting the lash adjusters should be partly filled with engine oil and it should be noted that when the plunger is depressed, the movement should be minimal. And if there is too much of this travel increase, immerse the rocker arm assembly in clean engine oil and pump the plunger until such travel is nudged out. When filled with oil the Plunger has to move within the rocker arm, if so then the Plunger is defected and has to be replaced. Bolt the hydraulic lash adjusters and rocker arms to their standard position in the cylinder head and then replaced the camshafts. The adjusters should make 'tapping' noises in the initial times after restarting the engine after replacement. The process is to keep increasing the engine speed reiteratively from idle to 3000 rpm and back to idle for one minute; if the adjusters are noisy, as they should be, they will have to be replaced.

To remove the lifters, first take off the intake manifold and valve covers, followed by the rocker arms and pushrods, and then the cylinder heads from the engine block. After removing the retaining plate bolts, lift the plate to access the hydraulic roller lifters, which are retained with an alignment yoke that should be lifted off.

Common causes of noisy lifters include dirt trapped inside and insufficient oil flow, viscosity, or pressure. It is important to check the oil for fuel contamination, correct level, cleanliness, and viscosity before concluding that the lifters are at fault.

Remove each rocker arm and lash adjuster, placing them in labeled bags.

The installation follows the reverse order of removal.

After reinstalling the lifters, run the engine to check for oil leaks.