ADAPTER 7W1645 - Caterpillar

Valve Lash Check
Measure the valve lash between the rocker arm and the valve bridge. Perform checks and 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".An adjustment is NOT NECESSARY if the valve lash is within the tolerance that is listed in Table 1.
Table 1
Valve Lash Check: Engine Stopped
Valves Acceptable Valve Lash Range
Inlet 0.43 to 0.58 mm (0.017 to 0.023 inch)
Exhaust 1.19 to 1.35 mm (0.047 to 0.053 inch) If the measurement is not within tolerance, adjust the valve bridge and then adjust the valve lash.Valve Bridge Adjustment
The valve bridge must be adjusted before the valve lash is adjusted. The valve bridge can be adjusted without removing the rocker arms and shafts. 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".Note: If the cylinder head is disassembled, keep the bridges with the respective valves. Check that the bridge dowels are installed to the correct height. Lubricate the bridge dowel, the bore for the bridge dowel, and the top contact surface of the bridge. Install the bridge on the dowel.Use the following procedure to adjust the valve bridges:
Illustration 1 g00662524
(1) Valve cover
(2) Transformer
(3) Ignition harness
Remove valve cover (1).
Disconnect ignition harness (3).
Grasp transformer (2) and pull the transformer straight out of the cylinder head.
Illustration 2 g00808424
(4) Adjusting screw
(5) Locknut
(6) Valve bridge
(7) Rocker arm
Loosen locknut (5) and adjusting screw (4).
Press straight down on rocker arm (7) 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 (5) to 30 4 N m (22 3 lb ft).
Make sure that the valve lash is correct. Refer to "Valve Lash Check".
Install transformer (2).
Connect ignition harness (3).
Install valve cover (1). Valve Lash Adjustment
The valve bridge must be adjusted before the valve lash is adjusted. Note: You can use the 147-5482 Valve Lash Gauge Group to measure the valve lash. Refer to the Special Instruction, REHS0128 that is included with the tool group. You will also need the 147-2056 Dial Indicator or the 147-5537 Dial Indicator.
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 lightly tap each rocker arm at top of the adjustment screw. This will ensure that the lifter roller