Removal & Installation Chevrolet Blazer S15

Unscrew rocker arm stud from cylinder head. To install, insert NEW rocker arm stud. Tighten to 35 ft. lbs. (47 N.m).

Remove upper and lower intake manifold. See INTAKE MANIFOLD (UPPER) and INTAKE MANIFOLD (LOWER) . Remove valve covers. Remove push rods. See ROCKER ARMS & PUSH RODS . Remove stuck valve lifter using Valve Lifter Remover (J-9290-01).

Installation

Coat lifter base or roller (if equipped) and body with High Viscosity Oil/Zinc (12345501) or equivalent. Install lifters in original location. To complete installation, reverse removal procedure. Replace oil and filter, and add High Viscosity Oil/Zinc (GM P/N 12345501) or equivalent.

Remove front cover. See FRONT COVER . Remove timing chain and sprockets. See TIMING CHAIN & SPROCKETS . Install three 5/16" X 18 bolts (4-5 inches long) into camshaft threaded holes. Use bolts to remove and install camshaft.

Coat camshaft lobes and bearing journals with High Viscosity Oil/Zinc (12345501). Ensure bearing oil holes align with oil holes in block. On engines where oil holes are difficult to see, use a piece of 3/32" rod to check alignment. Install outer camshaft bearing first. Install camshaft. To complete installation, reverse removal procedure.

1. Remove radiator. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C condenser (if equipped) and grille. Remove valve lifters. See «VALVE LIFTERS»(ref-54865-S09415675252001011700000) .
2. Remove timing chain and camshaft sprocket. See «TIMING CHAIN & SPROCKETS»(ref-54865-S42184389562001011700000) . Remove balance shaft gears. Remove balance shaft retainer plate.
3. Remove intake manifold. See «INTAKE MANIFOLD»(ref-54865-S41273407312001011700000) . Using a soft-faced hammer, tap balance shaft out toward front of engine.

1. Apply oil to balance shaft bearings. Using Installers (J-36996 and J-8092), install balance shaft in block. (Scheme 12) Install lifter retainer (if equipped). Ensure balance shaft turns.
2. Install thrust plate. Install balance shaft gears. Ensure timing marks on balance shaft gears are aligned. (Scheme 13) Install balance shaft timing gear bolt. Tighten bolt to 15 ft. lbs. (20 N.m), then tighten bolt an additional 35 degrees. To complete installation, reverse removal procedure.

Scheme 12

Scheme 13

Remove transmission, clutch (M/T) and flywheel. See appropriate TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. Pry seal from housing.

1. Lubricate inner and outer diameter of seal with engine oil. Place seal on Seal Installer (J-35621). Position seal against crankshaft as indicated in illustration. (Scheme 14)
2. Thread attaching screws into crankshaft flange and tighten with screwdriver. This squares seal with crankshaft. Rotate seal installer handle until it bottoms. Remove seal installer. Install flywheel, clutch (M/T) and transmission.

Scheme 14