ISM, ISMe, and QSM11 – 001-006   Bearings, Main

Used bearings must be installed in the same location from which they were removed.

Use Lubriplate™ 105 multi-purpose lubricant, or equivalent, to coat the inside diameter of the upper main bearing shell.

Install the upper main bearing shells (2) using the same method used to remove them.

The tang side (1) of the bearing must go into place last.

CAUTION  Low oil pressure faults can occur if more than one set undersize main bearings are installed in the same engine.

NOTE: Both upper and lower undersize main bearing shells must be installed as a set in the same block location.

Undersize main bearing installation procedures are the same as standard main bearings procedures. Both upper and lower undersized main bearing shells must be installed as a set in the same block location.

For undersize main bearing installation, mark the outside back of the main cap X -0.003 X with a permanent white Dykem™ marker to identify bearing location for future repairs. Allow the Dykem™ to dry before oil is added.

Install the lower main bearing shells with the bearing tang (1) in the slot (2) of the main bearing cap.

Use Lubriplate™ 105 multi-purpose lubricant, or equivalent, to coat the inside diameter of the bearing shells.

Apply Loctite™ 518 anaerobic sealant to four locations on each main bearing cap.

Apply a bead of Loctite™ 518 anaerobic sealant to the main bearing cap mounting surface, as shown.

Repeat this procedure on the opposite side of the main bearing cap.

CAUTION  The bead must be 3 to 5 mm [0.12 to 0.2 in] wide and must not enter the main bearing shell inside diameter. Sealant in the main bearing can cause engine damage.

Locate the leading edge of the main bearing cap clearance chamfer.

Apply a bead of Loctite™ 518 anaerobic sealant to the leading edge of the main bearing cap clearance chamfer (as shown).

Repeat this procedure on the opposite side of the main bearing cap.

To reduce the possibility of bore size issues, clearance issues, or both, the main bearing capscrews must be tightened within 15 minutes of the Loctite™ 518 anaerobic sealant application.

Use Lubriplate™ 105 multi-purpose lubricant, or equivalent, to coat the lower thrust bearings.

Install the lower thrust bearings in the number 4 main bearing cap, as shown.

The grooves of the thrust bearing must be toward the crankshaft.

The locating dowels must not protrude above the thrust bearing surface.

Use clean 15W-40 oil to coat the capscrew threads and both sides of the washers.

Drain the excess oil from the capscrews before installing them in the cylinder block.

The Number 4 main bearing cap must be aligned with the dowel pins in the bearing saddle when the capscrews are tightened.

The main bearing caps are numbered 1 through 7 from front to rear in the cylinder block. The caps must be installed so the number on the cap matches the bearing saddle in the block. The lock tangs in the main bearing saddle and bearing cap must be on the same side.

Install the main bearing caps.

Do not hit the main bearing cap with a hammer.

Make sure the proper main cap capscrew torque procedure is used when torquing main bearings. The use of the improper torque procedure will damage the engine.

Tighten all older blocks (prior to Engine Serial Number (ESN) 35011095) main bearing capscrews in alternating sequence to the following torque values:

All torque-to-yield blocks (ESN first 35011095) or blocks with TTY stamped on the rear engine serial number stamp pad must be tightened in alternating sequence to the following torque values:

Use a dial indicator to measure the crankshaft end clearance.

Crankshaft End Clearance

If the end clearance is not within the specifications, inspect the main bearing cap and thrust bearing surfaces in the cylinder block.