Category Archives: Service Manual

Front Cover and Timing Chain

Removal Disconnect and remove batteries and tray. Drain engine coolant. Remove radiator upper and lower hoses. Loosen crankshaft pulley belts. Remove left and right splash shields. Disconnect hood harness then remove hood with aid of helper. Place hinge pins in hinges after removal to avoid losing them. Remove air conditioning condenser and power steering fluid…
Read more

Oil Pump Drive

Removal Remove engine cover/console for access to rear of engine. Clean surface of drive, block and drive clamp with carb cleaner. Remove bolt that secures oil pump drive clamp to block (Figure 2-12). Remove oil pump drive with turn and lift motion. Use channel lock or use grip pliers to remove drive. Remove gasket from…
Read more

Front Cover Oil Seal Replacement

Remove crankshaft pulley and torsional damper. Refer to procedures in this section. Remove oil seal front cover with pry tool (Figure 2-11). Clean seal contact surface of torsional damper. Smooth surface, if necessary, with 180 grit emery. Then polish with 220 grit emery coated with engine oil. Seal surface must be smooth to avoid damaging…
Read more

Torsional Damper

Removal Remove crankshaft pulley and serpentine belt. Refer to procedure in this section. Remove damper bolt and nut (Figure 2-9). Remove torsional damper with special tool 5740755 (Figure 2-10). Remove and inspect crankshaft keys. Replace keys if worn, chipped, or distorted. [caption id="attachment_32361" align="aligncenter" width="580"] Figure 2-9: Torsional Damper and Crankshaft Pulley[/caption] [caption id="attachment_32362" align="aligncenter" width="475"]…
Read more

Crankshaft Pulley

Removal Loosen (but do not remove) crankshaft pulley bolts (Figure 2-6). Remove serpentine accessory drive belt as follows: Loosen drive belt by rotating belt tensioner in counterclockwise direction (Figure 2-7). Use 1/2 in. drive breaker bar to rotate pulley. Slide belt off tensioner and other pulleys. Then remove belt. Remove crankshaft pulley screws and remove…
Read more

Engine Mounting Bracket/Insulator

Removal Disconnect air cleaner hoses at air horn. Then remove air horn from intake manifold. Remove upper half of fan shroud extension (for fan clearance when engine is raised). Remove nuts/bolts attaching front propeller shaft center bearing to bracket. Mark front propeller shaft U-joint and yoke position with paint or chalk. Then remove front propeller…
Read more

Engine Troubleshooting

ENGINE WILL NOT CRANK Perform Electrical Troubleshooting Remove serpentine belt Remove all glow plugs. Using socket and breaker bar at crankshaft pulley, rotate engine clockwise and check for mechanical or hydraulic seizure. If crankshaft will not turn, check for bearing failure. If crankshaft turns and liquid is discharged, determine if liquid is coolant or fuel.…
Read more

6.5L NA Diesel Engine Operation

Some HUMMER models are equipped with the 6.5L naturally-aspirated diesel engine. A diesel engine can offer many features which are not available with gasoline engines: • More power at lower engine speeds for increased control • Greater fuel efficiency • Less maintenance required (due to compression ignition instead of spark ignition) • Heavy-duty construction Unlike…
Read more