Rainier AWD L6-4.2L (2007)
Crankshaft Main Bearing: Technical Service Bulletins
Engine - Broken Bolt Extraction Information
INFORMATION
Bulletin No.: 05-06-01-026B
Date: October 21, 2008
Subject:
Information On Torque to Yield Bolt Breakage and Use of Bolt Extractor Tool Kit Part Number EN-47702 for Removing Broken Cylinder Head or
Main Bearing Cap Bolts on Inline Truck Engines
Models:
2004-2007 Buick Rainier
2002-2009 Chevrolet TrailBlazer
2004-2009 Chevrolet Colorado
2002-2009 GMC Envoy
2004-2009 GMC Canyon
2002-2004 Oldsmobile Bravada
2006-2009 HUMMER H3
2005-2009 Saab 9-7X
with 2.8L, 2.9L, 3.5L, 3.7L or 4.2L Vortec Inline Engine (VINs 8, 9, 6, E, S - RPOs LK5, LLV, L52, LLR, LL8)
Supercede:
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-06-01-026A (Section 06 - Engine/Propulsion System).
A Torque To Yield (TTY) bolt, like a cylinder head bolt or main bearing cap bolt, may break during repair procedures. Interaction between a TTY bolt
and threads may cause the bolt to bind or break on removal.
Prior to removing the cylinder head or main cap bolts, perform the following procedure:
Using an appropriately sized punch and hammer, rap on the head of each bolt. The vibration produced by this procedure will assist in successful
removal.
If a head bolt or main bolt breaks during engine disassembly, a broken bolt extractor kit (EN-47702) has been released to assist in removal of the
remaining bolt segment. Many times the remaining bolt segment will back out easily with a pick tool or a reverse twist drill bit.
Bolt Replacement & Tightening
Important:
Never reuse TTY main bearing or cylinder head bolts. Always make sure that the engine block threaded holes are clean and do not place oil or
threadlocker on the bolts.
Utilize a thread chase tool followed by cleaning with dry compressed air to insure threads are clean and dry prior to installation of new TTY bolts. Bolts
that creak and snap while tightening will fail due to excessive torque caused by threads contaminated with debris, antifreeze or oil. Trace amounts of oil
or antifreeze will cause this condition. In extreme cases the threads may need additional cleaning with a non-residue cleaner like a brake clean product
followed by drying with clean & dry compressed air.
