Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
Notice: When adding coolant, it is important that you use GM Goodwrench DEX-COOLTM coolant. If coolant other than DEX-COOLTM is added to the system, the engine coolant will require change sooner: at 50 000 km (30,000 miles) or 24 months.
Important: Do not rotate flex coupling more than 4 degrees as damage may occur.
Important: Before you install the coolant pump, read the entire procedure. Follow the tightening sequences in order to avoid part damage and to provide proper sealing.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Tighten Tighten nuts to 26 N·m (19 lb ft).
Tighten Tighten the bolts to 14 N·m (124 lb in).
Tighten Tighten bolts to 26 N·m (19 lb ft).
Notice: The timing chain on the LD9 (VIN T) Twin Cam Engine is not to be replaced with the timing chain from any other model year. The timing sprockets are different on the Twin Cam engine and the shape of the links matches the sprockets. Engine damage may result if the wrong timing chain is used. The timing chain and the crankshaft sprocket must be marked so that they are reinstalled in the same side facing out at the time of reassembly.
Notice: Do not attempt to pry the sprocket off the camshaft or damage to the sprocket or chain housing could occur.
Important: Mark the timing chain and the crankshaft sprocket prior to removal. If the chain or the crankshaft sprocket is installed with the wear pattern in the opposite direction, noise and increased wear may occur.
Some scoring of the timing chain shoe and the guides is normal.
Install the intake and exhaust camshaft sprockets onto the camshafts with the marked surface showing.
Tighten Tighten the bolts to 70 N·m (52 lb ft) while holding the sprockets with the J 39579 .
Notice: Do not rotate the crankshaft clockwise to TDC. Valve or piston damage could occur.
Important: The side of the timing chain that was marked during removal must be showing when the chain is installed.
Important: Use the following steps in order to reset the timing chain tensioner assembly to the zero position.
Tighten Tighten the bolts to 10 N·m (89 lb in).
Important: If the timing chain tensioner is not released from the installation position, engine damage will occur when the engine is started.
Tighten Tighten the bolt to 16 N·m (12 lb ft).