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 used again. Bolts, studs, or other fasteners
that must be replaced are called out in the specific service procedure. |
| • | First design engine blocks cylinder head bolts have different torque/angle
specifications using both medium length 100 mm (3.94 in) and long 155 mm
(6.1 in) M11 cylinder head bolts. Second design engine blocks use only the
medium length 100 mm (3.94 in) bolt with a common torque/angle specification. |
Disassembly and Assembly Procedure Revisions
| • | For certain applications, a spacer plate has been added between the flywheel
and rear of the crankshaft. It is necessary to remove the spacer plate prior to removal
and installation of the crankshaft rear oil seal and clutch pilot bearing. |
| • | 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
All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics
is a uniform approach for repairing all systems. The diagnostic flow may always be
used in order to resolve a system condition. The diagnostic flow is the place to start
when repairs are necessary. For a detailed explanation, refer to
Strategy Based Diagnosis
in General Information or
Diagnostic Starting Point - Engine Mechanical
.
New Special Tools Required
| • | Angle Meter J 45059
has been
developed to provide technicians with a convenient method to tighten bolts that require
the torque angle tightening strategy. |
A Component Comparison from the Previous Year
| • | Exhaust gas recirculation (EGR) system has been deleted on all applications. |
| • | A spacer plate between the crankshaft and flywheel is required for applications
using the 4L80-E transmission. |
| • | All 2004 applications use a piston with a graphite coated skirt. |
| • | The positive crankcase ventilation valve is a non-serviceable
fitting on the left rocker arm cover. |
| • | The fuel rails for all engines except the L59 are returnless fuel systems.
The fuel pressure regulator for those engines is now a part of the fuel pump module. |
| • | First design applications use a piston pin that is floating fit to the
piston and press fit to the connecting rod. Second design applications use a piston
pin that is full-floating to both the piston and connecting rod. |
| • | The first design piston, pin, and connecting rod are to be serviced as
an assembly. |
