K 2500 Truck 4WD V8-6.0L VIN U (1999)
Connecting Rod: Technical Service Bulletins
Engine - Second Design Connecting Rod Bolt & Torques
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 99-06-01-011
Date: June, 1999
SERVICE MANUAL UPDATE
Subject:
Second Design Connecting Rod Bolt and Torque Specification
Models:
1997-99 Chevrolet Corvette
1998-99 Chevrolet Camaro
1998-99 Pontiac Firebird
1999 Chevrolet and GMC C/K Models (Silverado and Sierra)
with 4.8 L, 5.3 L, 5.7 L, or 6.0 L V8 Engine VINs V, T, G, U - RPOs LR4, LM7, LS1, LQ4)
This bulletin is being issued to revise the Fastener Tightening Specifications and the Piston, Connecting Rod, and Bearing Installation procedures in
Section 6 Engine Mechanical of the Service Manual. A second design connecting rod bolt will be introduced for the 1999 model year. Either design bolt,
(when used in pairs and properly tightened) may be used with 1997-99 connecting rods. Add the second design bolt description and torque specifications
to the appropriate Service Manual information.
Identify the type of connecting rod bolt.
^
The first design connecting rod bolt (1) can be identified by a single dimple/mark on the head of the bolt and no retaining sleeve (3) on the bolt
shank.
^
The second design connecting rod bolt (2) can be identified by two dimples/marks on the head of the bolt and a retaining sleeve (3) on the bolt shank.
Important:
When replacing the connecting rod bolts, both bolts MUST be of the same design for each connecting rod assembly. The use of different design
connecting rod bolts on the same connecting rod may lead to uneven clamploads and/or connecting rod bearing bore distortion.
