Skylark V6-181 3.0L (1986)
The 1985 "Torque to Yield" bolt was readily identifiable. It had a cut down shank (See Figure 3). The 1986 bolt is not readily identified and can
easily be mistaken for a regular bolt.
The only outward difference between the current 1986 torque to yield bolt and the past model bolt, is the indentation on the head of the 1985 bolt
(See Figure 3).
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Torque Specifications
Once you have determined which bolt you are using, refer to the following for correct tightening specifications. Failure to use the correct
specifications may result in broken head bolts, improper clamping load - too tight or loose, leaking head gaskets, etc.
Tightening Specifications - Torque to Yield Head Bolts
1.
Apply a heavy body thread sealer to threaded areas of bolt.
FIGURE 1 - CYLINDER HEAD BOLT TIGHTENING SEQUENCE
FIGURE 2 - CYLINDER HEAD BOLT TIGHTENING SEQUENCESEQUENCE SAME AS FOR TORQUE TO YIELD
2.
Torque cylinder head bolts to 34 N-m (25 ft.lbs.) per sequence shown in Figure #1.
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Should you reach 81 N-m (60 ft.lbs.) at anytime in Steps
3 & 4, you should stop at this point. Do Not complete the balance of the 90~ turn on this bolt.
3.
After completing Step 2, tighten each bolt 1/4 turn (90~) in same sequence.
4.
Repeat Step 3, tightening each bolt an additional 1/4 turn (90~).
NOTE:
Care should be taken when handling the new composition gasket used on 1986 engines to prevent surface or edge damage prior to installation.
Also, the gasket should be installed without the use of sealers of any kind.
Torque Specifications - Regular Head Bolts
1.
Apply a heavy body thread sealer to threaded area of bolts.
2.
Torque cylinder head bolts gradually, three times around in the proper sequence, then torque to 108 N-m (80 ft.lbs.).
