DISC ASSEM. 2S4983 - Caterpillar

Remove Rocker Shafts And Push Rods
start by:a) remove valve covers 1. Remove bolts (1) and lift shaft (2) and the rocker arms off the valve cover base and the push rods. 2. Remove push rods (3) from the valve lifters and valve covers base.3. Remove bridge assemblies (4) from the dowels.Install Rocker Shafts And Push Rods
1. Loosen the adjustment nuts and screws (1) on valve bridges (2).2. Put clean engine oil on the bridge dowels, the inside diameter of valve bridges (2) and on the top pad of the valve bridge. Install valve bridges (2) on the bridge dowels as shown. 3. While bridges (2) are pushed straight down with a force of 25 20 N (5.6 4.5 lb.) on the top contact surface, turn adjustment screw (1) until it makes contact with the valve stem. Turn screw (1) another 20° to 30°. This will straighten the dowel in the guide and make compensation for clearance (slack) in the threads.4. Hold adjustment screw (1) in position and tighten the nut around screw (1) to a torque of 30 4 N m (22 3 lb.ft.). 5. Put push rods (3) in position in the valve lifters and valve cover base.
Make sure the crankshaft and camshafts are in time with each other and that adjustment screws (5) are turned all the way out before the rocker shaft bolts are tightened or damaged to the valves or pistons can be the result. See INSTALL CAMSHAFTS for the procedure to time the engine.
6. Put the rocker arms and shaft (4) in position on the valve cover. Make sure the rocker shafts and push rods are in alignment and install the bolts to hold shaft (4).7. Make an adjustment of the valves to have a clearance of 0.40 mm (.016 in.) for intake and 0.76 mm (.030 in.) for exhaust. See VALVE CLEARANCE SETTING in TESTING AND ADJUSTING section for the complete procedure.end by:a) install valve covers