Hydraulic Lash Adjusters

The hydraulic lash adjusters are designed to keep the lash between the rocker arm and the valve at a constant rate, and also eliminate almost all periodical adjustment of the valve lash. The lash adjuster is a precision part, and it needs to be kept free from dust and other foreign matter. The lash adjusters do not need to be disassembled.

Fig. 1: The location of the lash adjuster and lash adjuster retainer upon installation

Fig. 2: Cross-section diagram of the hydraulic lash adjuster

3.5L Engines

CAUTION
In the cylinder from which the lash adjuster is removed, the piston interferes with the valve when the valve is pushed down. Therefore, turn the crankshaft to keep the piston position down. In addition, the rocker arm located at the valve lifted by the camshaft cannot be removed. Therefore, turn the crankshaft to keep the camshaft from lifting the valve before removal of the rocker arm.

Using the special tool, press the valve down and remove the roller rocker arm.
Pull out the lash adjuster from the cylinder head.
To install:
Install a new lash adjuster, with all air previously removed, to the cylinder head.
With the valve pressed down by the special tool, install the roller rocker arm.

Fig. 3: Press the valve down by using the tool MD998782

Fig. 4: While the valve is depressed, removal and installation of the roller rocker arm and lash adjuster is facilitated

All Other Engines

For the procedures for all other engines refer to the camshaft removal and installation procedures, located in this section.