GMC 1989 Light Duty Truck, Repair Manual, Page: 538 / 998

6A7-2 6.2 LITER DIESEL
CONTENTS (CONTINUED)
SUBJECT PAGE
A s s e m b ly ...................................................................................................................................................................................... 6 A 7 -2 0
Crankshaft Installation.......................................................................................................................................................... 6 A 7 -2 0
Flywheel In s ta lla tio n .............................................................................................................................................................6 A 7 -2 2
Connecting Rod and Piston In s ta lla tio n .........................................................................................................................6 A 7 -2 2
Camshaft Installation.............................................................................................................................................................6 A 7 -2 3
Timing Chain and Sprocket Installation...........................................................................................................................6 A 7 -2 4
Front Cover Installation........................................................................................................................................................ 6 A 7 -2 4
Oil Pump In s ta lla tio n .............................................................................................................................................................6 A 7 -2 5
Oil Pan Installation................................................................................................................................................................. 6 A 7 -2 6
Injection Pump In s ta lla tio n ..................................................................................................................................................6 A 7 -2 6
Torsional Damper Installation............................................................................................................................................. 6 A 7 -2 6
W ater Pump In s ta lla tio n ...................................................................................................................................................... 6 A 7 -2 7
Hydraulic Lifter Installation..................................................................................................................................................6 A 7 -2 7
Cylinder Head Installation ....................................................................................................................................................6 A 7 -2 8
Pushrod and Rocker Arm In s ta lla tio n ............................................................................................................................. 6 A 7 -2 9
Rocker Arm Cover In s ta lla tio n ...........................................................................................................................................6 A 7 -2 9
W ater Crossover Installation............................................................................................................................................... 6 A 7 -3 0
Dipstick Tube In s ta lla tio n ....................................................................................................................................................6 A 7 -3 0
Exhaust Manifold In s ta lla tio n ............................................................................................................................................. 6 A 7 -3 0
Glow Plug In s ta lla tio n ...........................................................................................................................................................6 A 7 -3 0
Injection Nozzle In s ta lla tio n ............................................................................................................................................... 6A7-31
Injection Line In s ta lla tio n .................................................................................................................................................... 6A7-31
Intake Manifold Installation..................................................................................................................................................6A7-31
Oil Pump Drive or Vacuum Pump Installation................................................................................................................6 A 7 -3 2
Engine Accessory In s ta lla tio n ...........................................................................................................................................6 A 7 -3 2
Engine Set-Up and T e s tin g ..................................................................................................................................................6 A 7 -3 2
S p e c ific a tio n s .............................................................................................................................................................................6 A 7 -3 6
Special T o o ls ............................................................................................................................................................................... 6 A 7 -3 9
DESCRIPTION
GM 6.2L diesel engines are 90 degree V8 type, natu­
rally aspirated, with indirect type combustion chambers.
The crankshaft is supported by five precision insert
main bearings, with crankshaft thrust taken at the number
three (center) main bearing.
The camshaft is supported by five plain type bearings
and is chain driven. Motion from the camshaft is transm it­
ted to the overhead valves by roller type hydraulic lifters,
pushrods, and shaft mounted rocker arms. The valve
guides are integral in the cylinder head.
The connecting rods are forged steel, with precision in­
sert type crankpin bearings. The piston pins are retained
by snap ring retainers.
For engine identification information, refer to GENERAL
INFORMATION (SEC. OA).
ENGINE LUBRICATION
A lubrication schem atic is shown in figure 1.
The gear type oil pump is driven from either the
vacuum pump shaft or from a drive gear, depending on
engine application. The vacuum pump or drive gear is
driven by the cam shaft. Oil is drawn into the pump
through a pickup screen and pipe.
Pressurized oil is routed to the oil cooler, located in the
radiator. A bypass valve is provided should the oil cooler
become restricted. Oil flows from the cooler to a full flow
oil filter. An oil filter bypass valve is provided should the oil
filter become restricted.
Oil flows from the oil filter to the oil galleries, providing
pressurized lubrication to various components.
The hydraulic valve lifters receive oil from the oil
galleries. Oil flows from the hydraulic lifters through
hollow pushrods to the rocker arms. Oil from the overhead
drains back to the crankcase through oil drain holes.
The pistons, rings, piston rings, cylinder walls, and
connecting rod small end bearings are lubricated by oil
splash.