The purpose of New Product Information is to highlight or indicate important
product changes from the previous model year.
Changes may include one or more of the following items:
| • | Torque values and/or fastener tightening strategies |
| • | Changed engine specifications |
| • | New sealants and/or adhesives |
| • | Disassembly and assembly procedure revisions |
| • | Engine mechanical diagnostic procedure revisions |
| • | New special tools required |
| • | A component comparison from the previous year |
Torque Values and/or Fastener Tightening Strategies
| • | All fasteners and threaded holes on the 4.8, 5.3, and 6.0 liter engines
utilize metric threads. |
| • | Cylinder head, connecting rod, crankshaft balancer, and main bearing
cap bolts now apply a torque angle strategy. |
| • | Certain fasteners should not be reused. Bolts, studs, or other fasteners
that must be replaced will be called out in the specific service procedure. |
Changed Engine Specifications
| • | The internal components for the 4.8, 5.3, and 6.0 liter engines are of
a new design and have specific tolerances and clearances for each component. |
| • | Cylinder boring and honing is permitted on the 1999 engine block. |
| • | A 0.5 mm (0.2 in) oversize piston and piston ring set are
available for service. |
New Sealants and/or Adhesives
| • | Threadlocking material is used on the fuel rail, intake manifold, cylinder
head M8/M11, flywheel, and exhaust manifold bolt threads. |
| • | A pipe sealant type material is used on the engine block coolant and
oil gallery plugs, oil pressure sensor threads, and engine block oil pan surface. |
| • | A sealant type material is used on the flange of the M8 crankshaft bearing
cap side bolts. |
Disassembly and Assembly Procedure Revisions
| • | The 4.8, 5.3, and 6.0 liter engine front and rear covers are adjustable
and must be aligned properly with the oil pan surface and crankshaft assembly. |
| • | The 4.8, 5.3, and 6.0 liter engine oil pans are a structural member of
the powertrain and must be aligned properly with the rear of the engine block and
transmission bellhousing. |
| • | Crankshaft balancer installation has a specific procedure to ensure complete
installation. |
| • | Early design water pumps will have a bolt-on drive belt pulley. Later
design water pumps will have a non-removeable press-on drive belt pulley. |
| • | The piston, pin, and connecting rod are to be serviced as an assembly. |
| • | Newer design pistons have a graphite coated piston skirt. The coated skirt
outside diameter (OD) may be slightly larger than the cylinder bore inside
diameter (ID) and the piston assembly may have a slight interference fit to
the cylinder bore during initial installation. |
Engine Mechanical Diagnostic Procedure Revisions
Base Engine Misfire, Valve Train, and other diagnostic information is now provided
in table form. Potential or probable causes are supplied for each specific concern.
New Special Tools Required
| • | A variety of new tools have been developed to assist in engine disassembly,
assembly, and on-vehicle service. |
A Component Comparison from the Previous Year
| • | In the new C/K applications, the L30/L31 engines have been replaced by
the new 4.8, 5.3, and 6.0 liter LR4, LM7, and LQ4 products. |
| • | Some of the new features include: |
| - | L30/L31 engines have a cast aluminum lower and composite upper intake
manifold assembly. The 4.8, 5.3, and 6.0 liter engines have a composite one piece
design. |
| - | L30/L31 crankshafts have two bolt main caps with the thrust bearing in
the number five journal (except heavy duty applications). The 4.8, 5.3, and 6.0 liter
crankshafts have six bolt main caps with the thrust bearing in the number three
journal. |
| - | L30/L31 ignition system includes one ignition coil, a crankshaft sensor,
and a distributor assembly. The 4.8, 5.3, and 6.0 liter ignition system includes
a crankshaft sensor, camshaft sensor, and eight individual ignition coils. |
| - | L30/L31 have a stamped steel oil pan. The 4.8, 5.3, and 6.0 liter engines
have a cast aluminum structural oil pan. |
