2/3/2010
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GM Cylinder Head Tightening Specification Clarification
This bulletin was issued to clarify GM 4.0L and 4.6L cylinder head tightening specifications found in previously published service manuals.
Affects:
1993 Cadillac Allante, Sixty Special (FWD)
1993-96 Cadillac Fleetwood
1993-99 Cadillac DeVille, Eldorado, Seville
1994-99 Cadillac Concours
1995-99 Oldsmobile Aurora
with 4.0 L or 4.6 L Engine (VINs C, Y, 9 - RPOs L47, LD8, L37)
Cylinder Head Installation
Torque specification and sequence for the cylinder head bolts (1-10) using a torque angle meter (J 36660-A):
1. First Pass - 30 ft.lbs. (40 N-m)
2. Second Pass - 70 Degrees
3. Third Pass - 60 Degrees
4. Fourth Pass - 60 Degrees (190 Degrees total)
The torque specification for the three front M6 cylinder head bolts is:
106 in.lbs. (12 N-m)
Some or all of this information was provided by the Automotive
Parts Remanufacturers Association (APRA). For more information on
technical bulletins available through APRA call 703-968-2772 or visit www.AutoBulletins.com.