Suburban 3/4 Ton 4WD V8-454 7.4L (1986)
Cylinder Head Bolts: Technical Service Bulletins
Engine - Incorrect Head Bolt Torque
Number:
86-142
Section:
6A
Date:
AUG., 1986
Subject:
SERVICE MANUAL REVISION - HEAD BOLT TORQUE
Model and Year:
1986 LIGHT AND MEDIUM DUTY TRUCKS WITH THE 6.0L, 7.0L AND 7.4L ENGINES
TO:
ALL CHEVROLET DEALERS
If it becomes necessary to remove and reinstall the cylinder heads from a 1986 6.0L, 7.0L, or 7.4L engine, the torque for the cylinder head bolts listed in
the service manuals (95 ft.lbs.) is incorrect. The correct torque for these bolts is 80 ft.lbs.
It is important for each dealer to correct their service manuals in order to reflect this change.
Light Duty - Page 6A6-33 Medium Duty - Page 6A3-60 Light Duty Unit Repair Manual - Page 6A5-44
