Installation of Main Bearing Bolts

INSTALLATION OF MAIN BEARING BOLTS

Two types of main bearing bolts are used on the engines of 1992-95 vehicles: non-elastic and elastic. Before installing either type of bolt, coat the bolt threads with clean engine oil.

NOTE:
Designations such as "Turbo," "Non-Turbo," "SOHC," and "DOHC" are only used if these items cause variation to the torque information of the engine.


Non-Elastic Main Bearing Bolts

The following vehicles use non-elastic main bearing bolts:

^ 1992 Eclipse and 1992 Galant 4G6 (2.0L)
^ 1992 Expo and 1992 Truck, 4G6 (2.4L)
^ 1992-95 Mirage, 4G1 (1.5L)
^ 1992-94 Eclipse, 4G3 (1.8L)
^ 1995 Eclipse, 420A (2.0L), Non-Turbo (Use bolt tightening sequence chart.)
^ 1995 Galant, 6G7 (2.5L) (Use bolt tightening sequence chart.)
^ 1992-95 Truck, 1992-95 Diamante, 1993-95 Diamante Wagon, 1992-95 3OOOGT, and 1992-95 Montero, 6G7 (3.0L) (Use bolt tightening sequence chart.)
^ 1994-95 Montero, 6G7 (3.5L) (Use bolt tightening sequence chart.)

To install non-elastic main bearing bolts, the following procedure is applicable to all vehicles/engines listed above, except the 420A (2.0L) engine.

1. Tighten the bolts on each main bearing cap equally, until the specified torque is reached. Use the bolt tightening sequence, if applicable. Refer to the sequence chart.

On the 420A (2.0L) engine, the tightening method is slightly different:

1. Check the bolts for damage by laying a straight edge against the threads. If the threads are not even and level against the straight edge, replace the bolt. Refer to the illustration.
2. Tighten bolts # 1 through # 10 (in sequence) to 75 Nm (55 ft.lbs.). Refer to the sequence chart.
3. Tighten bolts A through K (in sequence) to 28 Nm (20 ft.lbs.). Refer to the sequence chart.




Main Bearing Bolt Tightening Torque for Non-Elastic Bolts




Tightening Sequences for Non-Elastic Main Bearing Bolts (Engines not shown in the chart DO NOT have a specific main bearing bolt tightening sequence.)


Elastic Main Bearing Bolts (Plastic/Angle Tightening Method) The following vehicles/engines use elastic main bearing bolts:

1993-95 Mirage and 1992-95 Expo LRV, 4G9 (1.8L)
1993-95 Eclipse and 1993 Galant, 4G6 (2.0L)
1993-95 Expo, 1993-95 Expo LRV, 1993-95 Truck, and 1994-95 Galant, 4G6 (2.4L)




Before reusing an elastic bolt, measure its shank length. The shank measurement extends from the tip of the threads to the shoulder of the bolt head (NOT to the shoulder of the washer). If the specified shank measurement is exceeded, the bolt must be replaced.




Shank Measurements for Main Bearing Bolts
(Replace bolt if measurement is exceeded or if the bolt is visually damaged.)

To tighten elastic main bearing bolts using the plastic/angle tightening method, the following procedure is applicable to all engines listed above.


1. Torque bolts (in sequence) to specification. (Refer to page 9.)
2. Using a breaker bar (not a torque wrench), tighten each bolt an additional 1/4 turn (in sequence), plus another 1/4 turn (in sequence).





Main Bearing Bolt Tightening Torque for Elastic Bolts




Tightening Sequences for Elastic Main Bearing Bolts