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 LS1/LS6 engines utilize metric
threads. |
| • | Cylinder head, connecting rod, crankshaft balancer, and main bearing
cap bolts now apply a torque angle tightening strategy. |
| • | 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. |
| • | Certain fasteners should not be used again. Bolts, studs, or other fasteners
that must be replaced will be called out in the specific service procedure. |
New Sealants and/or Adhesives
Canadian SPO part numbers have been added. Refer to
Sealers, Adhesives, and Lubricants
.
Disassembly and Assembly Procedure Revisions
| • | 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
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
| • | A timing chain guide has been added to the valve train system. The nylon
chain guide is retained to the front of the engine block by two bolts. |
| • | The positive crankcase ventilation (PCV) system is now incorporated into
the engine valley cover for both LS1 and LS6 applications. |
| • | The first design piston, pin, and connecting rod are to be serviced as
an assembly. |
| • | First design applications use a piston pin that is floating fit to 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. |
