Somerset V6-181 3.0L (1986)
Cylinder Head Bolts: Technical Service Bulletins
Cylinder Head - Recap of Torque to Yield Bolt
Bulletin 86-6-23
Date
Aug. '86
Ref. No. 86-136-6
SUBJECT:
RECAP OF "TORQUE TO YIELD" BOLT INFORMATION
MODELS AFFECTED: 1985 3.0L (VIN CODE L) ENGINES LATE MODEL 1985 3.8L (VIN CODE 3) ENGINES 1986 3.0L (VIN CODE L) and
3.8L (VIN CODES A, B, 3 AND 7) ENGINES
NOTE:
It is suggested that a copy of the information provided in this bulletin be provided to all dealership technicians with the request that they
become familiar with its contents.
Earlier bulletins attempted to introduce you to "Torque to Yield Head Bolts" used on the above engines, and the difference between them and past model
fasteners for this application. Recent information indicates a need to expand on the information already provided. (Ref. Bulletins 85-6-3, 86-6-14,
85-6-17, and 86-6-2).
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What are "Torque to Yield" Bolts?
"Torque to Yield" bolts differ from regular fasteners in that they are tightened to the point where they literally start to stretch or "yield", thus
providing the greatest possible clamping force. When torqued to this point, it reduces the tendency of the bolt to relax it's clamping load, something
which does not happen with conventional bolts. This also means that torque to yield head bolts and regular head bolts should not be mixed for any
application.
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Identification
FIGURE 3 - CYLINDER HEAD BOLTS
