General Description - GMC T Series 1994 Repair Manual

Intake M anifold..................................................................................................................................................6A2-23
Exhaust Manifold.............................................................................................................................................. 6A2-23
Cylinder Head.....................................................................................................................................................6A2-23
Valve Lifters.......................................................................................................................................................6A2-27
Oil Pump Overhaul........................................................................................................................................... 6A2-28
Thread Repair.....................................................................................................................................................6A2-30
Assembly of Engine.............................................................................................................................................. 6A2-31
Prior to Assembly............................................................................................................................................. 6A2-31
Crankshaft Installation...................................................................................................................................... 6A2-31
Crankshaft Rear Oil Seal Installation............................................................................................................ 6A2-31
Camshaft Installation......................................................................................................................................... 6A2-32
Flywheel Installation......................................................................................................................................... 6A2-32
Piston and Connecting Rod Installation........................................................................................................6A2-32
Oil Pump Drive Installation............................................................................................................................6A2-34
Oil Pump Installation........................................................................................................................................ 6A2-34
Oil Pan Installation........................................................................................................................................... 6A2-34
Valve Lifter Installation................................................................................................................................... 6A2-35
Cylinder Head Installation...............................................................................................................................6A2-35
Rocker Arm and Pushrod Installation...........................................................................................................6A2-35
Valve Rocker Arm Cover Installation.......................................................................................................... 6A2-36
Crankshaft Sprocket Installation..................................................................................................................... 6A2-36
Timing Chain, Tensioner and Camshaft Sprocket Installation................................................................. 6A2-36
Crankcase Front Cover Oil Seal Installation...............................................................................................6A2-37
Crankcase Front Cover Installation............................................................................................................... 6A2-37
Crankshaft Pulley Hub Installation................................................................................................................ 6A2-37
Crankshaft Pulley Installation......................................................................................................................... 6A2-37
Coolant Pump Installation................................................................................................................................6A2-37
Coolant Inlet Installation..................................................................................................................................6A2-38
Coolant Outlet, Thermostat and Adapter Installation................................................................................. 6A2-38
Exhaust Manifold Installation......................................................................................................................... 6A2-38
Intake Manifold Installation.............................................................................................................................6A2-38
Oil Filter, Connector ad By-pass Valve Installation.................................................................................. 6A2-40
Oil Fill Tube Installation.................................................................................................................................6A2-40
Start-up Procedures........................................................................................................................................... 6A2-40
Specifications...........................................................................................................................................................6 A2-41
Fastener Tightening Specifications................................................................................................................. 6A2-41
Special Sealers, Adhesives, Thread Lockers and Lubricants.....................................................................6A2-41
Engine Specifications........................................................................................................................................ 6A2-43
Special Tools........................................................................................................................................................... 6A2-45
CYLINDER BLOCK
The cylinder block is made of cast iron and has
four cylinders arranged "In-Line." Five main bearings
support the crankshaft which is retained by recessed
bearing caps that are machined with the block for
proper alignment and clearances. Partial length water
jackets are around each cylinder.
CYLINDER HEAD
The aluminum cylinder head has individual
intake and exhaust ports for each cylinder. The valve
guides are cast iron and pressed into the cylinder head.
The valve seats are powder metal steel and also
pressed into the cylinder head. The rocker arms are
retained on individually threaded studs.

GENERAL DESCRIPTION

CRANKSHAFT AND BEARINGS
The crankshaft is cast nodular iron and is
supported by five main bearings. Number 4 bearing is
the thrust bearing. Main bearings are lubricated from
oil holes which intersect the main oil gallery on the
left side of the block.
PISTONS AND CONNECTING RODS
The pistons are cast aluminum with steel struts
and use two compression rings and one oil control
ring. The piston pin is offset toward the major thrust
side. This allows a gradual change in thrust pressure
against the cylinder wall as the piston travels its path.