Valve Lifters: Removal & Installation GMC Envoy I

Removal

Remove upper intake manifold. See INTAKE MANIFOLD (UPPER) . Remove lower intake manifold. See INTAKE MANIFOLD (LOWER) . Remove valve covers. Remove push rods. See ROCKER ARMS & PUSHRODS . Remove valve lifter guide. Remove stuck valve lifter using Valve Lifter Remover (J-3049-A).

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 oil supplement (1052367) or equivalent.

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(ref-1456-S18711585852001121700000) . Remove negative battery cable. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Drain cooling system. Remove front grille from vehicle. Remove radiator and A/C condenser. Remove interior engine cover (if equipped). Remove the generator and the generator mounting bracket. Remove lower intake manifold. See «INTAKE MANIFOLD (LOWER)»(ref-1456-S39226791962000031300000) . Remove the valve covers. Remove the push rods. See «ROCKER ARMS & PUSHRODS»(ref-1456-S20287707962000031300000) . Remove the valve lifters. See «VALVE LIFTERS»(ref-1456-S32591278422000031300000) . Remove the front cover. See «FRONT COVER»(ref-1456-S09894237352000031300000) .
2. Align timing chain timing marks. Remove camshaft sprocket bolts, camshaft sprocket and timing chain. Remove CKP sensor reluctor ring using Puller (J-8433-1) and Puller Plate (J-41371). Remove crankshaft sprocket, use Sprocket Puller (J-28509) on 7.4L or (J-5825-A) on all others. 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 with Zinc (12345501) or equivalent. 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. Fill and bleed cooling system. Replace oil and filter, and add High Viscosity Oil with Zinc (12345501) or equivalent.

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(ref-1456-S18711585852001121700000) . Disconnect negative battery cable. Drain cooling system. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove radiator, A/C condenser (if equipped) and grille. Remove lower intake manifold. See «INTAKE MANIFOLD (LOWER)»(ref-1456-S39226791962000031300000) . Remove valve lifters. See «VALVE LIFTERS»(ref-1456-S32591278422000031300000) . Remove accessory drive belt, water pump and front cover. See «FRONT COVER»(ref-1456-S09894237352000031300000) .
2. Remove CKP sensor reluctor ring using Puller (J-8433-1) and Puller Plate (J-41371). Remove the timing chain and the camshaft sprocket. Remove the crankshaft sprocket, using (J-5825-A). See «TIMING CHAIN & SPROCKETS»(ref-1456-S18921480282000031300000) . Remove balance shaft gears. Remove balance shaft retainer plate. Using a soft-faced hammer, tap balance shaft out toward front of engine.

Note. Front bearing is removed with balance shaft. Replace front bearing and balance shaft as a set only. Replace balance shaft timing gears as a set only.

1. Apply oil to balance shaft bearings. Using Installers (J-36996 and J-8092), install balance shaft in block. (Scheme 15) 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 16) 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. Tighten all nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(ref-1456-S12800425072000031300000) table.

Scheme 15

Scheme 16

Release fuel system pressure. See FUEL PRESSURE RELEASE. Disconnect negative battery cable. Remove transmission, clutch (M/T) and flywheel. On A/T see appropriate TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. On M/T see appropriate article in CLUTCHES. Pry seal from housing. (Scheme 17)

Note. On 4.3L, 5.0L & 5.7L, DO NOT allow oil or any other lubricant to contact seal surface of oil seal.

Coat seal with clean engine oil (7.4L). Place seal on Seal Installer (J-35621 for 4.3L, 5.0L and 5.7L, or J-38841 for 7.4L). Thread attaching screws into crankshaft flange and tighten. This squares seal with crankshaft. Rotate seal installer handle until it bottoms. Remove seal installer. Install flywheel, clutch (M/T) and transmission. To complete installation, reverse removal procedure. Tighten all retaining nuts and bolts to specification. See TORQUE SPECIFICATIONS .

Scheme 17