How do you time a 350 gmc motor - Sierra 1500HD GMC Cars & Trucks

4.8L, 5.3L and 6.0L Engines

1. • Timing mark alignment-4.8L, 5.3L & 6.0L
     
     
   • Locate the camshaft sprocket alignment mark in the 6 o'clock position and install the camshaft sprocket and timing chain
   • Camshaft sprocket bolts and tighten the camshaft sprocket bolts;
     1. Torque to: 26 ft. lbs. (35 Nm)
   • Oil pump
   NOTE: Do not lubricate the oil seal sealing surface.
   
2. Lubricate the outer edge of the oil seal with clean engine oil.
3. Lubricate the front cover oil seal bore with clean engine oil.
4. Install the crankshaft front oil seal with a suitable seal installer. NOTE: Do not apply any type sealant to the front cover gasket (unless specified). Special tools are used to properly align the engine front cover at the oil pan surface and to center the crankshaft front oil seal.
   
5. Install the front cover gasket, cover, and bolts onto the engine.
6. Install the front cover-to-oil pan bolts and do not overtighten.
7. Tighten the cover bolts finger tight and do not overtighten. J41480 installation-4.8L, 5.3L & 6.0L
   
   
8. Start the J41480 or other suitable tool to front cover bolts but don’t tighten the bolts yet. NOTE: Align the tapered legs of the tool with the machined alignment surfaces on the front cover.
   Seal alignment tool installation-4.8L, 5.3L & 6.0L
   
   
9. Install tool J41476 or other suitable tool.
10. Install the crankshaft balancer bolt and tighten the crankshaft balancer bolt by hand until snug but do not overtighten.
11. Tighten the J41480 bolts and front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
12. Remove the tools. NOTE: Place a straight edge across the engine block and front cover oil pan sealing surfaces. Avoid contact with the portion of the gasket that protrudes into the oil pan surface. Insert a feeler gauge between the front cover and the straight edge tool. The cover must be flush with the oil pan surface or no more than 0.5 mm (0.02 in) below flush. If the front cover-to-engine block oil pan surface alignment is not within specifications, repeat the cover alignment procedure. If the correct front cover-to-engine block alignment cannot be obtained, replace the front cover.
    
13. Snug the oil pan-to-cover bolts in order to position the cover at the pan rail.
14. Tighten the oil pan-to-front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
15. Tighten the front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
16. Install the crankshaft balancer and bolt (See: Crankshaft Damper).
17. Install the water pump (See: Water Pump).
18. Fill the engine to the proper level with oil.
19. Fill the engine to the proper level with coolant.
20. Test drive the vehicle to confirm the repairs.

1. Before servicing the vehicle refer to the precautions at the beginning of this section.
2. Remove the upper intake manifold sight shield as follows:
   • Remove the retaining bolt in the front of the shield
   • Lift up on the front of the shield, then lift the shield off the rear bracket
3. Drain the cooling system.
4. Remove or disconnect the following:
   • Negative battery cables
   • Right front wheel
   • Right front fender splash shield
   • Upper fan shroud
   • Fan clutch (See: Engine Fan and Clutch)
   • Drive belt
   • Oil dipstick tube
   • Thermostat housing crossover
   • Crankshaft damper (See: Crankshaft Damper)
   • Crankshaft front oil seal
   • Water pump (See: Water Pump)
   • Camshaft sensor electrical connector
   • Camshaft sensor bolt and sensor
   • Crankshaft Position (CKP) sensor connector, bolt and sensor
   • CKP sensor spacer bolts and spacer
   • 5 bolts securing the upper oil pan to the front cover
   • Bracket bolts and the bracket for the turbocharger outlet coolant pipe
   • Engine front cover bolts
   • Use a suitable seal cutter to separate the front cover from the cylinder block and upper oil pan NOTE: Do not bend the turbocharger outlet pipe.
     
   • O-ring from the front cover Engine front cover-6.6L engine
     
     
   • Oil pressure relief valve from the front cover

1. Clean and inspect all sealing surfaces.
2. Install or connect the following:
   • Oil pressure relief valve with a new O-ring and tighten the valve
     1. Torque to: 30 ft. lbs. (41 Nm)
3. Apply a 1/8 in. (2-3mm) wide to 1/16 in. (0.5-1.5mm) high bead of sealant to the front cover sealing surfaces to the engine block and oil pan.
4. Install or connect the following:
   • New front cover O-ring after lubricating it with engine oil
   • Front cover and bolts and tighten the front cover bolts
     1. Torque to: 15 ft. lbs. (20 Nm)
   • Upper oil pan-to-front cover bolts and tighten the bolts
     1. Torque to: 15 ft. lbs. (20 Nm)
   • Turbocharger coolant outlet pipe bracket and bolts and tighten the bolts
     1. Torque to: 15 ft. lbs. (20 Nm).
   • Camshaft sensor and bolt and tighten the bolt
     1. Torque to: 80 inch lbs. (9 Nm)
   • Camshaft sensor connector NOTE: The CKP sensor spacers are machined with different timing positions. If you have to replace a spacer, make sure it has the same part number.
     
   • CKP sensor spacer and spacer bolts and tighten the bolts
     1. Torque to: 89 inch lbs. (10 Nm)
   • CKP sensor and bolt and tighten the bolt
     1. Torque to: 89 inch lbs. (10 Nm)
   • Water pump (See: Water Pump)
   • Crankshaft front oil seal
   • Crankshaft damper (See: Crankshaft Damper)
   • Thermostat housing crossover
   • Oil fill tube
   • Drive belt
   • Upper fan shroud
   • Right front fender splash shield and wheel
   • Negative battery cables
5. Refill the cooling system with the proper type and quantity of antifreeze.
6. Inspect the engine for leaks.
7. Test drive the vehicle to confirm the repairs.