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The procedure for tightening TTY head bolts on GM 3.8L engines?
What is the procedure for tightening TTY head bolts on GM 3.8L engines?
The AERA Technical Committee offers the following information regarding cylinder head installation for 1995-2002 GM 3.8L VIN K and 1 engines. AERA TB 1952 should be discarded. According to AERA, other published service information has been incomplete and this is the most up to date information.
It is important to remember that the cylinder head bolts used for these engines should be replaced any time the heads are re-installed. Failure to replace the bolts during head installation may reduce clamping force and head gasket service life.
To install new head bolts on these engines, use a torque angle tool and:
- Thoroughly clean the threads in the block using a 7/16-14 tap.
- Install the head gasket with the arrow pointing to the front of the engine.
- Install the new cylinder head bolts dry.
Notice: This bolt is designed to permanently stretch when tightened. The correct part number fastener must be used to replace this type of fastener. If the correct bolt is not used, the parts will not be tightened correctly and the engine may be damaged.
Step 1: Tighten all bolts in sequence (see Figure 1) to 35-37 ft.lbs. (49-50 Nm).
Step 2: Rotate each bolt 130° in sequence.
Step 3: Rotate the center four bolts 1,2,3 and 4 an additional 30°.
Where do the different colored valve stem seals go on 2000-’02 Mitsubishis?
There have been reports of difficulty correctly identifying valve stem seals on 2000-’02 Mitsubishi VIN H engines. To properly identify the two different valve stem seals, Mitsubishi has color coded the seals.
There may not be an identification sheet in the packaging with the seals. To correctly identify which seals go on the intake and exhaust valves, see the chart in Figure 2.
Charcoal gray seals go with the exhaust valves and the green seals go with the intake valves.
The GM 6.6L Duramax has different thickness head gaskets. Which one should I use?
The AERA Technical Committee offers the following information regarding cylinder head gasket selection on 2001-’03 GM 6.6L VIN 1 Duramax diesel engines. Using the wrong head gasket on this engine could cause engine damage.
GM offers three different thickness head gaskets depending on the amount of piston protrusion the engine has. When measuring piston protrusion, make sure that you measure all pistons on each bank.
For the maximum value of protrusion for each bank, determine the proper gasket using the information from Figure 3. See Figure 4, for gasket grade mark location and bank location on the gasket.
Notice: The left and right cylinder head gaskets are not interchangeable. Improper placement of the cylinder head gasket will block coolant and oil passages and oil passages and will cause severe engine damage. The gasket markings face up when correctly installed.
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