55498 Mercruiser PLATE, Transom

1. Remove bolts (1) and the washers that hold rocker shaft assembly (2) in position.2. Remove rocker shaft assembly (2). Remove the O-ring seal from the rear rocker arm support bracket.3. Put identification marks on push rods (3) as to their location in the engine. Remove the push rods. The following steps are for the installation of the rocker shaft assembly and push rods.4. Loosen the adjusting screws (4) on the rocker arms for valve clearance. This will prevent a bent valve or push rod during installation of the rocker shaft assembly.5. Install push rods (3). The O-ring seal in the rear support must be installed new each time the bolt is removed from the rear support bracket.6. Put rocker shaft assembly (2) in position on the cylinder head.
Make sure the dowels on each end of the rocker shaft assembly are in alignment with the holes in the cylinder head.
7. Put 5P3931 Anti-Seize Compound on all of bolts (1) that hold the rocker shaft assembly in position except for bolt (10) that goes through the rear rocker arm support bracket. Install the bolts in the rocker shaft assembly.8. Hand tighten bolts (1) for the rocker shaft as follows:a. Tighten all the bolts in number sequence to a torque of 156 N m (115 lb.ft.).b. Tighten all the bolts in number sequence to a torque of 250 17 N m (185 13 lb.ft.).c. Tighten all bolts in the number sequence again to a torque of 250 17 N m (185 13 lb.ft.).9. The assembled length of springs at both ends of rocker shaft must be 1.50 0.25 mm (.059 .010 in.). Remove or install washers behind springs to change the assembled length of the springs.10. Make adjustments until the intake valve clearance is 0.038 mm (.015 in.) and the exhaust valve clearance is 0.64 mm (.025 in.). For the complete valve adjustment procedure see the topic, Valve Clearance Setting in Testing And Adjusting. Tighten the locknuts for adjusting screws (4) to a torque of 29 7 N m (21 5 lb.ft.).End By:a. install valve coverDisassemble & Assemble Rocker Shaft Assembly
Start By:a. remove rocker shaft assembly and push rods 1. Remove O-ring seal (1) from the rear support bracket. A replacement of the O-ring seal must be made each time the head bolt is removed from the rear support bracket. 2. Remove retainer ring (6), washer (5), spring (4) and washer (3) from each end of rocker shaft. Remove rocker arm (2). 3. Remove pin from rear support bracket with a hammer and punch. Remove rear support bracket (7) from shaft.4. Remove remainder of rocker arms, springs, washers and brackets.5. Remove plugs from each end of the shaft if necessary. The following steps are for the assembly of the rocker shaft. 6. Install rocker arms (2), brackets (8), washers (5) and springs (4) on the rocker shaft.7. Install rear support bracket (7) on rocker shaft. Make sure hole in rear support bracket is in alignment with hole in rocker shaft.8. Install pin (9) through bracket and shaft with a hammer.9. Pin (9) must extend 9.60 mm (.378 in.) above the bracket.10. Install O-ring seal (1) in the rear support bracket. Install rocker arm (2), washer, spring, washer and retainer ring on the rocker shaft.11. Install the plugs in each end of the rocker shaft if they were removed.End By:a. install rocker shaft assembly and push rods