Assembly

TOOL REQUIRED
^ J 36660 Torque Angle Meter
^ J 36005 Rear Crankshaft Seal Installer
^ J 38122 Balance Shaft Holder
^ J 39579 Camshaft Sprocket Wrench
^ J 36008-A Camshaft Sprocket Alignment Pins

1. Cylinder Block Plug Installation

a. Install the engine block coolant drain plug.
b. Apply gasket paste GM P/N 1050026 or equivalent to the plug before installation. Tighten Coolant Jacket Plug to 30 Nm (22 lb ft).
c. Install the oil passage plugs.
d. Apply gasket paste GM PIN 12345382 to the plugs before installation. Tighten Oil Passage Plugs to 30 Nm (22 lb ft).

2. Crankshaft, Bearings, and Bearing Cap Installation

a. Install the main bearings and lubricate with engine oil.

b. Install the crankshaft on the journals.

CAUTION: In order to prevent the possibility of cylinder block or crankshaft bearing cap damage, the crankshaft bearing caps are tapped into the cylinder block cavity using a brass, lead, or a leather mallet before the attaching bolts are installed. Do not use attaching bolts to pull the crankshaft bearing caps into the seats. Failure to observe this information may damage a cylinder block or a bearing cap.

c. Install the crankshaft caps. Tap gently into place with a suitable tool.
d. Install the crankshaft cap bolts. Finger tighten.
e. Seat the crankshaft thrust bearing. Tighten the bearing cap bolts to 20 Nm (15 lb ft), and rotate the bolts 90 degrees. Use the torque angle meter.

3. Crankshaft Rear Oil Seal and Housing Installation

a. Press the new crankshaft seal into the housing. Use the Rear Crankshaft Seal Installer. The installer also establishes the depth of the seal in the housing.
b. Position the new seal housing to block the gasket over the alignment dowel pins. The gasket is reversible.
c. Lubricate the lip of the crankshaft seal with engine oil.
d. Install the seal housing assembly.
e. Install the seal housing to the block bolts. Tighten the bolts to 12 Nm (106 lb in).

4. Piston, Connecting Rod, and Bearing Installation

a. Lubricate the cylinder bore with engine oil.
b. Lubricate the piston and bearing with engine oil.
c. Install the piston and rod assembly into the cylinder bore. Ensure that they are installed with the arrow pointing towards the front of the engine and the connecting rod oil squirt hole facing the left (exhaust) side of the engine.
d. Remove the thread protectors.

e. Install the rod cap.
f. Install the rod cap nuts. Tighten the nuts to 25 Nm (18 lb ft), then rotate 80 degrees using the torque angle meter.

CAUTION: The crankshaft must be positioned with the timing chain drive sprocket marks aligned with the timing mark on the engine block.

g. Install the crankshaft timing sprocket with the marked side facing out and rotate the crankshaft to align the keyway with the timing mark on the engine block.

5. Balance Shaft Housing Installation

a. Install the balance shaft assembly to the block. Use Loctite 272 GM P/N 12345493, or equivalent on the housing assembly to the block bolts.
b. If the balance shaft housing was disassembled, loosely assemble the housing assembly to the block.

c. Tighten the housing fasteners in sequence.
^ Tighten fasteners 1, 2, 4, 5, 6 and 7 to 15 Nm (11 lb ft) + 40 degrees.
^ Tighten fasteners 3 and 8 to 10 Nm (89 lb in) + 40 degrees.

d. Tighten the housing assembly to block bolts in sequence.
^ Tighten bolts 1,2 and 4 to 25 Nm (18 lb ft) + 70 degrees.
^ Tighten bolt 3 to 40 Nm (30 lb in) + 60 degrees.
^ Tighten bolt 5 to 53 Nm (39 lb ft).
e. Ensure that the balance shafts spin freely.
f. If the balance shaft housing was disassembled, install the oil pump pick-up screen into the housing. Lightly tap it into place with a plastic hammer.

CAUTION: If the balance shafts are not properly timed to the engine, the engine may vibrate or make noise.

g. Use the following steps to time the balance shaft to the engine:
^ Place the number one piston at Top Dead Center (TDC).
^ Rotate the crankshaft 90 degrees.
^ Install the balance shaft holder on to the balance shaft assembly in order to ensure that the shafts do not rotate while the driven sprocket bolt is tightened.

CAUTION: The surface that was marked during disassembly of the driven sprocket must show if it is going to be reused. This will insure that the chain continues to ride on the same surface. If a new driven sprocket will be installed, either surface can be placed against the shaft.

h. Install the driven sprocket to the shaft.

CAUTION: The balance shaft driven sprocket bolt is left hand threaded and must be tightened by rotating it in a counter clockwise direction.

i. Install the balance shaft driven sprocket bolt, finger tighten.

j. Install the balance shaft chain guide.
k. Press the chain guide tightly against the chain.
l. Tighten the chain tensioner bolt. Tighten the bolt to 13 Nm (115 lb in).
m. Tighten the balance shaft driven sprocket bolt. Tighten the bolt to 40 Nm (30 lb ft) and rotate the bolt 45 degrees.
n. Remove the balance shaft holder from the balance shaft housing assembly.
o. Loosen the balance shaft chain guide bolt.

NOTE: A brass feeler gauge needs to be used to ensure correct measurements are obtained. If a steel gauge is used, it will not bend to conform to the guide and will cause incorrect measurements.

p. Use the following procedure to adjust the balance shaft drive chain tension:
^ Inserting a 1 mm (0.040 inches) brass feeler gauge between the chain guide and the chain.
^ Press the guide against the chain. Use about three pounds of force.
^ Tighten the chain fastener bolt. Tighten the bolt to 13 Nm (115 lb in).
q. Install the balance shaft chain cover.

r. Install the balance shaft chain cover nut and bolt. Tighten the nut and bolt to 13 Nm (115 lb in).

6. Oil Pump Installation

a. Install the oil pump cover to the balance shaft housing.

b. Install the oil pump bolts to the balance shaft housing. Tighten the pump to housing bolts to 54 Nm (40 lb ft).

c. Install the balance shaft chain guide.

NOTE: A brass feeler gauge needs to be used to ensure correct measurements are obtained. If a steel gauge is used, it will not bend to conform to the guide and will cause incorrect measurements.

d. Use the following procedure to adjust the balance shaft drive chain tension:
^ Inserting a 1 mm (0.040 inches) brass feeler gauge between the chain guide and the chain.
^ Press the guide against the chain. Use about three pounds of force.
^ Tighten the chain fastener bolt. Tighten the bolt to 13 Nm (115 lb in).
e. Install the balance shaft chain cover.
f. Install the balance shaft chain cover nut and bolt. Tighten the nut and bolt to 13 Nm (115 lb in).

7. Timing Balance Shafts to Engine Installation

c. Tighten the housing fasteners in sequence.
^ Tighten fasteners 1, 2, 4, 5, 6 and 7 to 15 Nm (11 lb ft) + 40 degrees.
^ Tighten fasteners 3 and 8 to 10 Nm (89 lb in) + 40 degrees.

d. Tighten the housing assembly to block bolts in sequence.
^ Tighten bolts 1,2 and 4 to 25 Nm (18 lb ft) + 70 degrees.
^ Tighten bolt 3 to 40 Nm (30 lb in) + 60 degrees.
^ Tighten bolt 5 to 53 Nm (39 lb ft).
e. Ensure that the balance shafts spin freely.
f. If the balance shaft housing was disassembled, install the oil pump pick-up screen into the housing. Lightly tap it into place with a plastic hammer.

CAUTION: If the balance shafts are not properly timed to the engine, the engine may vibrate or make noise.

g. Install the timed balance shaft and housing assembly to the engine using the following steps:
^ Place the number one piston at TDC
^ Rotate the crankshaft 90 degrees
^ Install the balance shaft holder on to the balance shaft assembly to ensure the shafts do not rotate while the driven sprocket bolt is tightened.

CAUTION: A new balance shaft driven sprocket bolt must be used any time the bolt is removed. If a new bolt is not used, the balance shaft sprocket may slip allowing the balance shafts to become mistimed and cause engine vibration.

NOTE: The surface that was marked during disassembly of the driven sprocket must show if it is going to be reused. This will insure that the chain continues to ride on the same surface. If a new driven sprocket will be installed, either surface can be placed against the shaft.

j. Install the balance shaft chain guide.
k. Press the chain guide tightly against the chain.
l. Tighten the chain tensioner bolt. Tighten the chain tensioner bolt to 13 Nm (115 lb in).
m. Tighten the balance shaft driven sprocket bolt. Tighten the driven sprocket bolt to 40 Nm (30 lb ft). Use the torque angle meter in order to rotate the bolt an additional 45 degrees.
n. Remove the balance shaft holder from the balance shaft housing assembly..
o. Loosen the balance shaft chain guide bolt.

NOTE: A brass feeler gauge needs to be used in order to ensure correct measurements are obtained. If a steel gauge is used, it will not bend to conform to the guide and will cause incorrect measurements.

p. Adjust the balance shaft drive chain tension. Insert a 1 mm (0.040 inches) brass feeler gauge between the chain guide and the chain.
q. Press the guide against the chain using about three pounds of force.
r. Install the chain tensioner bolt. Tighten the chain tensioner bolt to 13 Nm (115 lb in).
s. Install the balance shaft chain cover.
t. Install the balance shaft chain cover nut and bolt. Tighten the chain cover nut and bolt to 13 Nm (115 lb in).

8. Cylinder Head Installation

a. Install the cylinder head gasket to the block.

CAUTION: Do not use any sealing material.

b. Install the cylinder head.

c. Lightly apply clean engine oil to the threads and the bottom side of the flange of the head bolt and allow the oil to drain before installing.

d. Install and tighten the cylinder head bolts in sequence.
^ Tighten bolts 1-8 to 65 Nm (40 lb ft).
^ Tighten bolts 9 and 10 to 40 Nm (30 lb ft).
^ Then turn all the bolts an additional 90 degrees in sequence. Use the torque angle meter.

9. Timing Chain Housing Installation

CAUTION: Ensure that the alignment dowel pins are in the cylinder block and the timing chain housing, before installing the timing chain housing. The dowel pins ensure proper chain housing and front cover location for correct front oil seal-to-crankshaft alignment.

a. Install the timing chain housing gaskets. Gaskets are reusable.
b. Install the timing chain housing. No sealer is needed.
c. Install the timing chain housing to the camshaft housing bolts and hand tighten.
d. Install the timing chain housing to the block fasteners and hand tighten.
e. Install the chain housing to the oil pan bolts and hand tighten.

f. Tighten the bolts.
^ (1) (M8 X 1.25 X 25) to 26 Nm (19 lb ft).
^ (2) (M10 X 1.25 X 55) to 50 Nm (37 lb ft).
^ (3) (M8 X 1.25 X 25) to 29 Nm (21 lb ft).

g. Install the camshaft sprockets. Sprockets are identical and interchangeable.
h. Clean the old sealer off of the bolt with a wire brush.
i. Clean the threaded hole in the camshaft with a nylon bristle brush.
j. Install the camshaft sprocket bolts and washers while holding the sprockets with camshaft sprocket wrench. Tighten the bolts to 70 Nm (52 lb ft).
k. Use Adhesive/Sealant Compound GM P/N 12345493 or equivalent on the camshaft sprocket bolts.

10. Water Pump Installation

NOTE: Use the following guidelines when servicing the cooling system or draining it for service procedures:
^ Add two coolant pellets, GM P/N 3634621 or equivalent, when the cooling system is serviced or drain for service procedures.
^ The pellets must be added to the radiator or the pressurized water reservoir.
^ Crush the pellets prior to installation.
^ Do not place the pellets into a non-pressurized coolant recovery reservoir. On these systems the pellets must be added to the radiator.
^ The sealant pellets may leave a film on the sides of the pressurized and non-pressurized water recovery reservoirs. This film is normal.
^ Prior to installing the water pump read the entire procedure. Pay special attention to the tightening sequence to avoid part damage and to ensure proper sealing.

a. Install the water pump cover to the coolant pump assembly.
b. Install the water pump bolts. Finger tighten the bolts.
c. Install the cover to the block bolts. Finger tighten the bolts.
d. Install the pump to chain housing nuts. Finger tighten the nuts.

NOTE: When the pump assembly to the housing nuts are tight there should be a gap between the seal and both the housing and the pump.

e. Use the following sequence to tighten the fasteners:
^ Install the pump assembly to the chain housing nuts. Tighten the nuts to 26 Nm (19 lb ft).
^ Install the pump cover to the pump assembly. Tighten the bolts to 14 Nm (124 lb in).
^ Install the cover to the block, bottom bolt first. Tighten the bolts to 26 Nm (19 lb ft).

11. Timing Chain, Sprockets, Tensioner Installation

CAUTION: Ensure that the camshaft sprocket alignment pins are in the cylinder block and the timing chain housing, prior to installing the timing chain housing. The camshaft sprocket alignment pins ensure proper chain housing and front cover location for correct front oil seal to crankshaft alignment.

a. Install the camshaft sprocket alignment pins through holes in the camshaft sprockets and into holes in the timing chain housing. This will position the camshaft for correct timing.
b. Use the following steps if the camshafts are out of position and must be rotated more than 1/8 turn to install the alignment dowel pins:

CAUTION: Failure to follow this procedure could result in severe engine damage.

^ The crankshaft must be rotated 90 degrees clockwise off of TCC to give the valves adequate clearance to open.
^ Once the camshafts are in position and the dowels are installed, rotate the crankshaft counter clockwise back to TDC.

CAUTION: Do not rotate the crankshaft clockwise to TDC. Valve or piston damage could occur. The timing chain and crankshaft sprocket must be put on in a specific direction for chain noise and wear considerations. The surfaces that were marked during removal should be showing when the chain and crankshaft sprocket are installed.

c. Install the timing chain over the exhaust camshaft sprocket around the coolant pump sprocket and around the crankshaft sprocket.
d. Remove the alignment dowel pin from the intake camshaft. Use the camshaft sprocket wrench in order to rotate the intake camshaft sprocket counter clockwise enough to allow the timing chain to slide over the intake camshaft sprocket.
e. Release the camshaft sprocket wrench. The length of the chain between the two camshaft sprockets will tighten.
f. If properly timed the intake camshaft alignment dowel pin will slide in easily. If the dowel pin does not fully index, the camshafts are not timed correctly and the procedure must be repeated.
g. Leave the alignment dowel pins installed.
h. The keyway on the crankshaft and the mark on the cylinder block should be aligned, with the slack removed from the chain between the intake camshaft sprocket and the crankshaft sprocket. If the mark and keyway are not aligned, move the chain on tooth forward or rearward, remove the slack and recheck marks.
i. Use the following steps in order to reload the timing chain tensioner assembly to its zero; position:
^ Form a keeper from a piece of heavy gauge wire.
^ Apply slight force on the tensioner shoe in order to compress the plunger.
^ Insert a small screwdriver into the reset access hole, and pry the ratchet pawl away from the ratchet teeth while forcing the plunger completely in the hole.
^ Install the keeper between the access hole and the blade.

j. Install the tensioner assembly to the chain housing.
k. Inspect the plunger assembly installation, it is correctly installed when the long end is toward the crankshaft.
l. Install the timing chain tensioner bolts. Do not over tighten. Tighten the bolts to 10 Nm (89 lb in).
m. Remove the alignment dowel pins.

CAUTION: The timing chain 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.

n. Rotate the crankshaft clockwise two full rotations. Align the crankshaft keyway with the mark on the cylinder block and reinstall the alignment dowel pins. The alignment dowel pins will slide in easily if the engine is timed correctly.
o. Install the timing chain guides.

12. [1][2]Engine Front Cover and Oil Seal Installation

a. Inspect the front cover gasket for damage before reusing the gasket

b. Install the front cover gasket. Front cover gaskets are reusable.
c. Install the front cover
d. Install the front cover bolts/nuts. Hand tighten. Tighten the bolts to 12 Nm (106 lb in).

13. Oil Pan Installation

a. Inspect the oil pan gasket for damage, replace as necessary. The oil pan gasket is reusable.
b. Install the oil pan gasket.
c. Install the oil pan.
d. Install the oil pan bolts and hand tighten.

e. Tighten the on pan bolts.
^ (1) (M8 X 1.25 X 80) to 24 Nm (18 lb ft).
^ (2) (M8 X 1.25 X 22) to 24 Nm (18 lb ft).
^ (3) (M6 X 1.00 X 25) to 12 Nm (106 lb in).
^ (4) to 26 Nm (19 lb ft).

14. Oil Filter Adapter and Valve Assembly Installation

a. Install oil filter bypass valve.
^ Insert a new oil filter bypass valve in the cylinder block
^ Use a center punch to stake the valve in three places.
b. Install the oil filter connector. Tighten the oil filter connector to 29 Nm (21 lb ft).
c. Install a new oil filter.
^ Lubricate the oil filter seal with clean engine oil before installation.
^ Tighten the oil filter 3/4 to one full turn after the gasket contacts the cylinder block.

15. Intake Manifold Installation

CAUTION: Never attempt to remove the intake manifold from a hot engine, allow the engine to cool to ambient temperature. The intake manifold is made of a composite plastic and can be damaged if it is removed when the engine is hot.

a. Install the EGR tube to the intake manifold. Tighten the bolts to 7 Nm (53 lb in).
b. Install the new gasket with the numbers stamped on the gasket faced toward the manifold surface.
c. Install the intake manifold gasket. The gasket is reusable if it is undamaged.

d. Install the intake manifold.

e. Install the intake manifold bolts and nuts. Follow the tightening sequence. Tighten the bolts and nuts to 22 Nm (16 lb ft).

f. Install the Throttle body. Tighten the bolts and nuts to 10 Nm (89 lb in).

16. Crankshaft Balancer and Hub Installation

a. Lubricate the front oil seal and sealing surface of the crankshaft balancer. Use Chassis Grease GM P/N 1051344 or equivalent.

b. Install the balancer onto the crankshaft indexing keyway. Tap the balancer into place using a rubber or sand filled mallet.

CAUTION: Do not use the torque angle meter to rotate the retaining bolt an additional 90 degrees. The torque capacity of the tool will be exceeded and damage to the tool will result.

c. Install the retaining bolt and washer. Tighten the bolt to 175 Nm (129 lb ft). Use the crankshaft balancer holder to prevent the crankshaft from rotating.
d. Put a mark on the socket next to one of the four marks on the crankshaft balancer holder. This mark will represent the zero point or O degrees. Tighten the bolt by rotating the socket clockwise 90 degrees. At 90 degrees the socket indexes with the next mark on the tool.

17. Exhaust Manifold Installation

a. Install the exhaust manifold gasket.

b. Install the exhaust manifold.

c. Install the exhaust manifold to the cylinder head retaining nuts. Follow the tightening sequence. Tighten the nuts to 13 Nm (115 lb in).
d. Install the exhaust manifold upper heat shield.

e. Install the exhaust manifold upper heat shield bolts. Tighten the bolts to 14 Nm (124 lb in).

f. Install the exhaust manifold brace to the exhaust manifold.
g. Install the exhaust manifold brace to the exhaust manifold bolt. Tighten the bolt to 56 Nm (41 lb ft).
h. Install the exhaust manifold brace to the oil pan.
i. Install the exhaust manifold brace to the oil pan nuts. Tighten the nuts to 26 Nm (19 lb ft).

18. Oil Level Indicator Tube Installation

a. Install the tube into the block.

b. Install the indicator tube bracket to the rear cam carrier lift bracket bolt. Tighten the nut to 10 Nm (89 lb in).

19. Flex Plate Installation

a. Install the flex plate.

b. Install the retainer if the vehicle has an automatic transmission.

CAUTION: This bolt is designed to permanently stretch when tightened. The correct part number fastener must be used to replace this type of fastener. Do not use a bolt that is stronger in this application. If the correct bolt is not used, the parts will not be tightened correctly. The system or the components may be damaged.

c. Install the new bolts or apply Adhesive/Sealant Compound GM P/N 12345493 or equivalent to all flex plate to crankshaft bolts that are being re-used. Carefully follow the instructions included with the thread locking compound in order to ensure proper bolt retention.
d. Holding the crankshaft balancer with the crankshaft balancer holder, tighten the bolts evenly. Tighten the bolts to 30 Nm (22 lb ft). Use the torque angle meter in order to rotate the bolts 45 degrees.

NOTE: After assembly, test the engine before installing it in the vehicle if possible. If a test stand is not available use the following procedure.

1. Fill the crankcase with oil.
2. If a new camshaft and lifters have been installed add Engine Oil Supplement to the engine oil.
3. Fill the cooling system with coolant.
4. Add cooling system sealing pellets to the engine cooling system. GM P/N 3634621 or equivalent.
^ Add the pellets directly to the radiator or pressurized coolant reservoir on systems that do not have caps on the radiator.
^ Crush the pellets before installation.
5. Crank the engine several times and listen for unusual noises or any other evidence of mechanical problems.
6. Start the engine.
7. Listen for any abnormal engine sounds.
8. Run the engine at 1000 RPM until the engine is at operating temperature.
9. After the engine is at operating temperature, shut the engine off and inspect it carefully for oil or coolant leaks.