N14 Base Engine Troubleshooting and Repair Manual – 001-006   Bearings, Main

WARNING  To reduce the possibility of personal injury, avoid direct contact of hot oil with your skin.

WARNING  Some state and federal agencies have determined that used engine oil can be carcinogenic and cause reproductive toxicity. Avoid inhalation of vapors, ingestion, and prolonged contact with used engine oil. If not reused, dispose of in accordance with local environmental regulations.

Drain the lubricating oil. Refer to Procedure 007-025 (Lubricating Oil Pan) in Section 7.

Remove the lubricating oil pan. Refer to Procedure 007-025 (Lubricating Oil Pan) in Section 7.

CAUTION  The main bearing caps are marked for position (1) on the camshaft side and the cylinder block identification (2) on the exhaust side. Mark any caps that are not marked before removing them from the cylinder block.

NOTE: Replace main bearings one at a time.

Remove the number 7 main bearing cap capscrews and washers.

NOTE: The number 7 main bearing cap has thrust bearings and dowel pins.

NOTE: The service tool listed below must be centered on the cap.

Use the main bearing cap puller, Part Number ST-1178, to remove the cap.

Remove the lower main bearing shell from the crankshaft journal.

NOTE: Mark the bearing shells with the journal number from which they were removed.

Remove the dowel ring.

Remove the thrust bearings from the number 7 cap.

Mark these bearings as the bottom front and the bottom rear thrust bearings.

CAUTION  Do not damage the crankshaft when removing the thrust bearings.

Use a blunt tool to remove the upper thrust bearings.

Mark these bearings as the top front and the top rear thrust bearings.

To remove the upper main bearing shell, install the main bearing roll out tool, Part Number 3823818, into the oil hole of the main bearing journal.

CAUTION  Do not use a capscrew or any hard metal object as this can damage the crankshaft and cause serious engine failure.

Rotate the crankshaft with the accessory drive pulley to remove the main bearing shell. Mark each main bearing for location if they are to be installed again in the engine.

Use a soft bristle brush to clean the parts, and dry with compressed air.

NOTE: Refer to Parts Reuse Guidelines, Bulletin 3810303, for information on bearing inspection.

Plastigage®

CAUTION  To reduce the possibility of the crankshaft falling, two evenly spaced main bearing caps must always be on the engine to support the engine crankshaft.

The inspection must be performed with the main cap bearings that will be used in the engine after the inspection and/or repair is completed.

The PR-1 (red) style Plastigage®, clearance range of 0.05 to 0.152 mm [0.002 to 0.006 in], is required for this procedure.

Do not destroy evidence. Go slowly and observe all conditions.

To Plastigage® the main bearing journal clearance on an in-chassis engine, shims must be inserted into the main caps on both sides of the journal being Plastigaged®. Shims support the crankshaft so an accurate clearance measurement can be made on the lower bearing.

Use a main bearing cap puller, Part Number ST-1178, to remove the caps. The main bearing cap puller must be centered on the cap. Pull straight down to remove the cap.

Remove the lower bearings.

Shims push the crankshaft up against adjoining upper bearings so an accurate clearance measurement can be made on the lower bearing.

The shims can be manufactured from a piece of 4-inch-diameter, schedule 40 PVC pipe. The dimensions of the fabricated shims must be as follows:

Width = 38.1 mm [1.5 in]

Thickness = 6.35 mm 0.25 in] (approximate thickness of schedule 40 PVC pipe)

Diameter = 101.6 mm [4.0 in].

Cut the pipe in half. The shims must be fabricated to the above-specified dimensions and be less than 180 degrees in circumference.

NOTE: Two fabricated shims are required for this procedure.

Install the shims in the main bearing caps on both sides of the bore being checked. (For example, to check the number 4 main bearing cap, install the shims on the number 3 and number 5 main bearing caps. To check the number 6 main bearing cap, install the shims on the number 5 and number 7 main bearing caps.)

Install the main bearing caps.

Install and tighten the capscrews.

Remove the main bearing cap to be Plastigaged®.

Wipe the oil from the bearing and crankshaft journal.

Cut or tear a piece of Plastigage® the full width of the bearing.

Do not squeeze the gauge material as this can result in a false reading.

Tear through both the envelope and plastic thread at the same time. Open the envelope lengthwise by cutting the edge with scissors or a knife or by tearing.

With the envelope open, lift out the Plastigage® by one end. Roll the material out with a thumb if the material is stuck lightly to the paper.

Occasionally, the color in the Plastigage® material will transfer to the paper. This has no effect on accuracy.

Place the piece of Plastigage® in the bearing shell approximately at the 6-o’clock position.

The Plastigage® clearance check procedure must be performed with the original bearings.

Do not disturb the Plastigage® before reading the measurement. Disturbing the Plastigage® can result in an incorrect measurement.

Install the main bearing cap using the appropriate torque procedure.

Remove the main bearing cap. The compressed Plastigage® will be located adhering to either the bearing shell or the crankshaft.

Compare the width of the compressed Plastigage® at its widest point, to the graduations on the envelope (regardless of taper). The number within the graduation on the envelope indicates the bearing clearance in thousandths of an inch or millimeters, depending on which side of the envelope is used.

Taper does not affect the clearance measurement. Clearance is still measured at the widest point on the Plastigage® strip.

If the compressed Plastigage® is less than 0.051 mm [0.002 in] at its widest point, the block must be pulled from service and repaired or replaced.

If the compressed Plastigage® is greater than 0.051 mm [0.002 in], reassemble the main bearing caps with either the existing or new main bearings.

Inspect the main bearing cap and capscrews for damage.

Inspect the bearing shells and the thrust bearings for nicks, scratches, or damage.

NOTE: If the main bearings are damaged, refer to the N14 Shop Manual, Bulletin 3810487 to inspect the crankshaft main bearing journals. If the crankshaft is damaged, the engine must be removed for repair. Refer to Procedure 000-001 (Engine Removal) in the N14 Shop Manual, Bulletin 3810487.

Use an outside diameter ball tipped micrometer to measure the main bearing shell thickness.

Standard Main Bearing Shell Thickness

Discard a main bearing shell if its thickness is below the minimum specification.

NOTE: For more detailed information of bearing damage, refer to Analysis and Prevention of Bearing Failures, Bulletin 3810387.

NOTE: Bearing shells are available for crankshafts which are 0.25 mm [0.010 in], 0.51 mm [0.020 in], 0.76 mm [0.030 in], or 1.02 mm [0.040 in] undersize. Crankshafts which are ground undersize in the connecting rod and main bearing journals are marked on the front counter weight. If the crankshaft is marked, check the bearing shell part number to make sure the correct bearing size is used.

NOTE: The upper main bearing shells have a groove and an oil hole to provide crankshaft lubrication. The lower main bearing shells do not have grooves or holes. The groove for the number 7 shell is not in the center of the shell. The wider part of the number 7 shell must be installed toward the flywheel end of the cylinder block.

CAUTION  The cylinder block saddle and the cap mating surfaces must be clean and dry when the bearing shells are installed. Used bearings must be installed in their original location.

CAUTION  The groove for the dowel ring must be next to the dowel ring counterbore in the cylinder block.

Use clean Lubriplate® 105 or its equivalent to lubricate the upper main bearing shell to crankshaft journal mating surface.

CAUTION  Do not use a capscrew or any hard metal object as this can damage the crankshaft and cause serious engine failure.

To install the upper main bearing shell, install main bearing roll out tool, Part Number 3823818, into the oil hole of the main bearing journal. Start the bearing into the upper saddle by hand. Take care that the roll-in tool does not slip between the bearing and the crank journal.

Use clean Lubriplate® 105 or its equivalent to lubricate the upper thrust bearings.

CAUTION  The grooves must be toward the crankshaft. Incorrect thrust bearing installation will result in engine damage.

Install the upper thrust bearings in the number 7 main bearing saddle.

NOTE: Push the crankshaft toward the rear of the engine to install the front bearing and to the front of the engine to install the rear bearing.

Install the dowel ring in the dowel ring counterbore of the cylinder block.

Install the lower main bearing shell as follows:

1. Use clean Lubriplate® 105 or its equivalent to lubricate the bearing shell to the crankshaft journal mating surface.

1. Align the bearing shell with the dowel ring.
2. Push on the side of the bearing shell opposite the dowel ring to install the bearing shell.

CAUTION  The grooves of the thrust bearing must be toward the crankshaft. The locating dowels must not protrude above the thrust bearing surface. Incorrect thrust bearing installation will result in engine damage.

Use clean Lubriplate® 105 or its equivalent to lubricate the lower thrust bearings.

Install the lower thrust bearings in the number 7 main bearing cap as shown.

Use clean 15W-40 oil to lubricate the capscrew threads and the flat washers.

Drain the excess oil from the capscrews before installing them.

CAUTION  The main bearing caps are marked for position (1) on the camshaft side and the cylinder block identification (2) on the exhaust side. The cylinder block identification number (3) is stamped on the pan rail on the camshaft side of the block. Install the caps in the correct position with the position number to the camshaft side and its part number toward the rear of the engine. Installation of main bearing caps into incorrect positions will result in severe engine damage.

Install the main bearing caps as follows:

1. Align the capscrew holes in the cap with the holes in the cylinder block. Make sure the ring dowel and the lower bearing shell are in position.

1. Install the capscrews and the washers through the cap and into the cylinder block.
2. Hand tighten the capscrews two to three threads.

NOTE: When hitting the cap, make sure the bearing shell and dowel ring do not move.

1. Hit the cap with a rubber mallet to push it into the correct position.

Tighten all older block (prior to engine serial number (ESN) 11875596) main bearing capscrews in alternating sequence to the following torque values:

All newer blocks (ESN first 11875596) must be tightened in alternating sequence to the following torque values:

Replace the main bearing shells number 1 through number 6.

NOTE: Main bearings number 1 through number 6 do not have thrust bearings.

Tighten the main bearing capscrews in the sequence shown.

Measure the end clearance of the crankshaft as follows:

1. Install a dial indicator to the oil pan flange.
2. Put the tip of the gauge against the crankshaft counter weight.
3. Push the crankshaft toward the rear of the cylinder block.

1. Set the dial indicator to zero.
2. Push the crankshaft toward the front of the cylinder block.
3. If the end clearance is less than 0.10 mm [0.004 in], do the following:

Loosen all main bearing capscrews one turn.

Push the crankshaft toward the front and then toward the rear of the cylinder block.

Tighten all older block (prior to engine serial number (ESN) 11875596) main bearing capscrews in alternating sequence to the following torque values:

All newer blocks (ESN first 11875596) must be tightened in alternating sequence to the following torque values:

Tighten the main bearing capscrews in the sequence shown.

Measure the crankshaft end clearance. The end clearance specification for a new or reground crankshaft with new thrust bearings is 0.10 to 0.45 mm [0.004 to 0.018 in].

NOTE: Crankshafts that have been reground on the thrust bearing surfaces are marked for oversize thrust bearings on the rear crankshaft counter weight. If the crankshaft counter weight is marked, check the thrust ring part number to make sure the correct thrust ring size is used.

Example: F.010 = Front 0.25 mm [0.010 in]

Example: R.020 = Rear 0.51 mm [0.020 in]

If the crankshaft end play is more than 0.56 mm [0.022 in], the crankshaft must be removed from the engine and repaired. Refer to the Alternate Repair Manual, Bulletin 3379035.

Install the lubricating oil pan. Refer to Procedure 007-025 (Lubricating Oil Pan) in Section 7.

CAUTION  The lubricating oil system must be primed before operating the engine after any internal engine repairs to avoid internal component damage.

Remove the temperature sensor from the lubricating oil pump cover.

Prime the lubricating system. Refer to Procedure 007-037 (Lubricating Oil System) in Section 7.

Fill the engine with lubricating oil. Refer to Procedure 007-025 (Lubricating Oil Pan) in Section 7.

Operate the engine until it reaches a temperature of 82°C [180°F], and check for lubricating oil leaks.