GMC T Series 1994 Repair Manual page 509

SUBJECT
Coolant Crossover Installation........................................................................................................................ .....6A 7-49
Dipstick Tube Installation........................................................................................................................................6A7-50
Exhaust Manifold Installation.......................................................... ...................................................................... 6A7-50
Glow Plug Installation.............................................................................................................................................. 6A7-50
Injection Nozzle Installation................................................................................................................................... 6A7-51
Injection Line Installation........................................................................................................................................6A7-51
Intake Manifold Installation.................................................................................................................................... 6A7-52
Oil Pump Drive Installation.................................................................................................................................... 6A7-52
Engine Accessory Installation...............................................................................................................................6A7-53
Rear Crankshaft Oil Seal Installation..................................................................................................................6A7-53
Flywheel Installation................................................................................................................................................. 6A7-54
Engine Setup and Testing...................................................................................................................................... 6A7-54
Specifications.................................................................................................................................................................6A7-55
Fastener Tightening Specifications......................................................................................................................6A7-55
Engine Specifications.............................................................................................................................................. 6A7-56
Service Piston and Cylinder Bore Specifications........................................................................................... 6A7-57
Crankshaft Main Bearing Selection and Specifications................................................................................ 6A7-58
Case, Camshaft and Camshaft Bearings Specifications.............................................................................. 6A7-58
Crankshaft Pin Journals and Connecting Rod B earings............................................................................. 6A7-58
Connecting Rod to Crankshaft Journal Bearing Clearance......................................................................... 6A7-58
Special T o o ls ........................................................................................... ...................................................................... 6A7-59
The 6.5L diesel engine is a 90-degree V8 type, with
indirect type combustion chambers. There are four ver­
sions of the 6.5L engine. Two of the engines are turbo­
charged (L56, VIN S and L65, VIN F) and the other two
are non-turbocharged naturally aspirated (L49, VIN P
and L57, VIN Y).
The crankshaft is supported by five precision insert
main bearings, with crankshaft thrust taken at the num­
ber three (center) main bearing.
The camshaft is supported by five plain type bearings
and is chain driven. Motion from the camshaft is trans­
mitted to the overhead valves by roller type hydraulic
lifters, pushrods, and shaft-mounted rocker arms. The
valve guides are integral to the cylinder head.
The connecting rods are forged steel with precision
insert type crankpin bearings. The piston pins are held
in place by retaining rings.
For engine identification information, refer to SEC­
TION OA.
For disassembled views of the 6.5L engine, refer to
figures 1 through 8.
CONTENTS (cont'd)
GENERAL DESCRIPTION
ENGINE LUBRICATION
A lubrication schematic is shown in figure 9.
The gear-type oil pump is driven from a drive gear.
The drive gear is driven by the camshaft. Oil is drawn
into the pump through a pickup screen and pipe.
Pressurized oil is routed to the oil cooler located
either inside of the radiator or in front of the radiator. A
bypass valve is provided to prevent against high oil
pressure on cold start up. Oil flows from the cooler to a
full-flow oil filter.
Oil flows from the oil filter to the oil galleries, provid­
ing pressurized lubrication to various components,
including the turbocharger.
The hydraulic valve lifters receive oil from the oil gal­
leries. 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, piston rings, cylinder walls, and connect­
ing rod small end bearings are lubricated by oil splash.
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