PLATE 2N9839 - Caterpillar

Table 1
Required Tools
Part Number Description
444-7035 Hydraulic Lash Adjuster Gauge Measure the valve lash between the rocker arm and the valve bridge. Perform the adjustments with the engine stopped. The valves must be fully closed. To determine whether the valves are fully closed, refer to Testing and Adjusting, "Finding the Top Center Position for the No. 1 Piston" and Testing and Adjusting, "Crankshaft Position for Valve Lash Setting".
Incorrect adjustment of the valve bridge and/or of the valve lash can result in engine damage from these conditions: excessive exhaust temperatures, incorrect seating of the valves and contact between the valves and the piston.
Valve Bridge Adjustment
Illustration 1 g03509419
(1) Valve cover
(2) Transformer
Remove valve covers (1). If a seal is damaged or deteriorated, obtain a new seal for assembly.
Remove transformer (2). If the O-ring seal is damaged or deteriorated, obtain a new O-ring seal for assembly.
Illustration 2 g03509186
(3) Locknut
(4) Adjustment screw
(5) Rocker arm
(6) Valve bridge
Loosen locknut (3) and adjusting screw (4).
Press straight down on rocker arm (5) at the contact point for valve bridge (6). Turn adjusting screw (4) clockwise until the screw just contacts the valve stem.
Tighten adjusting screw (4) for an additional 25 5 degrees in order to straighten the valve bridge onto the dowel.
Hold adjusting screw (4) in position and tighten locknut (3) to 30 4 N m (22 3 lb ft).
Make sure that the valve lash is correct. Refer to "Valve Lash Adjustment".
Make sure that O-ring seal is in good condition and install the transformer (2) .
Make sure that seal is in good condition and Install valve cover (1).Valve Lash Adjustment
The valve bridge must be adjusted before the valve lash is adjusted.
Ensure that the No. 1 piston is at the top center (TC) position. Refer to Testing and Adjusting, "Finding the Top Center Position for the No. 1 Piston".
Work on the appropriate cylinders that are listed in Testing and Adjusting, "Crankshaft Positions for Valve Lash Setting".
Before you perform any adjustments, use a soft hammer to tap lightly on each rocker arm at top the adjustment screw. This action will ensure that the lifter roller is seated against the camshaft.
Illustration 3 g03511179
(1) Hydraulic lash adjuster
(2) Locknut
(3) Adjustment screw
Loosen locknut (2) and adjusting screw (3).
With light force turn the adjustment screw (3) clockwise until the ball is seated into the cup of the hydraulic lash adjuster (1). Once contact is made, rotate the adjustment screw (3) clockwise an additional 360 45 degrees.
Hold adjusting screw (3) in place and tighten locknut (2) to a torque of 70 15 N m (52 11 lb ft).
Illustration 4 g06131969
(4) Hydraulic Lash Adjuster Gauge
Verify that the setting is correct using the 444-7035 Hydraulic Lash Adjuster Gauge (4). The hydraulic lash adjuster gauge should easily slide around the hydraulic lash adjuster without excessive drag or slop on the top and bottom of the gauge.
Remove the timing bolt from the flywheel housing. Rotate the crankshaft for 360 degrees. Install the timing bolt in the flywheel housing.
With the No. 1 piston in the top