REMOVAL & INSTALLATION
See Figures 1, 2, 3 and 4
- Remove the engine from the vehicle and place on a suitable workstand.
- Drain the crankcase and the cylinder block.
- Tag and disconnect the spark plug wires at the spark plugs, then remove the wires from the ignition harness brackets on the valve covers. If necessary, remove the distributor cap and spark plug wire assembly.
- Remove the spark plugs to allow easy rotation of the crankshaft.
- Remove the oil pan. If necessary remove the oil pump.
- Remove the engine front cover and water pump (if necessary) as an assembly.
- If equipped, remove the distributor drive gear.
- Remove the crankshaft sprocket, camshaft sprocket(s) and timing chain.
- Remove the flywheel and the engine rear plate.
- If equipped, remove and discard the 1-piece rear main seal.
Each connecting rod cap MUST be identified so it can be installed in its original position during assembly.
- Remove the connecting rod caps. Turn the crankshaft as necessary to position the connecting rod in the low point of travel before removing the connecting rod cap. After removing the connecting rod cap, push the piston into the cylinder block bore. Make sure the crankshaft journals are not damaged.
- Remove the crankshaft main bearing caps.
- Carefully lift the crankshaft out of the cylinder block to avoid damage to the bearing surfaces.
- If equipped, remove the split-type crankshaft rear oil seal, then discard.
- Lightly oil all bolt and stud bolts threads before installation. Make sure all crankshaft bearing surfaces and main bearings are clean.
- If the crankshaft main bearing journals have been refinished to definite undersize, remove the crankshaft main bearings from the cylinder block and main bearing caps.
- Install new crankshaft main bearings. Make sure the tabs on the main bearings engage the slots in the main bearing caps and cylinder block.
- Install the upper half of the split-type rear main seal. Make sure the crankshaft rear oil seal groove in the cylinder block is clean. Carefully lower the crankshaft into position in the cylinder block. Take care not to damage the crankshaft main bearing.
- Make sure the crankshaft split-type rear oil seal groove in the rear crankshaft main bearing cap is clean.
When using sealer, assembly must occur within 15 minutes after sealer application. After this time, the sealer may start to set-up, and its sealing effectiveness may be reduced.
- Apply a 1 / 8 in. (3mm) bead of Silicone Rubber to the rear main bearing cap-to-cylinder block parting line.
- Install the lower half of the split-type rear main seal.
- Lubricate the bearing surfaces with Engine Assembly Lubricant D9AZ-19579-D or equivalent. Install the main bearing caps and retaining bolts, except for the 5.0L engine. For the 5.0L engine, install all bearing caps, except the thrust bearing cap (no. 3 bearing).
For the 2.3L engine, tighten the main bearing cap retaining bolts in two steps, as follows:
- Step 1: to 50-60 ft. lbs. (68-81 Nm)
- Step 2: to 75-85 ft. lbs. (102-115 Nm)
For the 3.8L engine, tighten the main bearing cap retaining bolts as follows:
- Wedge a prybar between the cylinder block web and the crankshaft cheek in front of the No. 3 crankshaft main bearing. Do NOT jam the prybar into position. Carefully tap on the prybar until it holds the crankshaft toward the front of the engine.
- Tighten the main bearing cap bolts to 65-81 ft. lbs. (88-110 Nm) for vehicles through 1994 or to 81-89 ft. lbs. (110-120 Nm) for 1995-96 vehicles, then remove the prybar.
- For the 4.6L engine, tighten the main bearing cap bolt 1 / 2 turn, after the gasket contacts the sealing surface.
- For the 5.0L engine, tighten the main bearing cap retaining bolts, except the thrust bearing cap (No. 3) to 60-70 ft. lbs. (81-95 Nm). Install the thrust bearing cap with the bolts finger-tight.
- For the 5.0L engine, pry the crankshaft forward against the thrust surface of the upper half of the bearing. Hold the crankshaft forward and pry the thrust bearing cap to the rear. This will align the thrust surfaces of both halves of the bearing. Retain the forward pressure on the crankshaft, then tighten the thrust cap bolts to 60-70 ft. lbs. (81-95 Nm). Force the crankshaft toward the rear of the engine.
Check the crankshaft end-play, as follows:
- Pry against the No. 2 main bearing cap and check the crankshaft end play in both directions as shown in the accompanying figure.
- If end play exceeds specifications, grind the crankshaft and install an oversize crankshaft thrust main bearing or replace the crankshaft and crankshaft thrust main bearing.
- Install the one-piece crankshaft rear oil seal.
- If the crankshaft connecting rod journals have been refinished to a definite undersize, remove the bearing inserts from the connecting rods and rod caps. Install new bearings. Make sure the tabs on the insert securely engage the slot in the cap and rod.
- Rotate the crankshaft as necessary to bring each crankshaft throw to the lowest point of travel. Pull the piston downward until the connecting rod seats on the crank throw and install the rod caps.
- Check the connecting rod clearance. After each clearance check is completed, lubricate the bearing surfaces with Oil Conditioner D9AZ-19579-CA or equivalent before installing the connecting rod caps.
Tighten the connecting rod retaining nuts, as follows:
2.3L Engine: Step 1 to 25-30 ft. lbs. (34-41 Nm), then Step 2 to 30-36 ft. lbs. (41-49 Nm)
- Install the timing chain and front cover (water pump) assembly, as outlined earlier in this section.
- If equipped, install the distributor drive gear.
- Install the oil pan and, if necessary, the oil pump.
- Install the rear cover plate and flywheel, as outlined.
- Install the spark plugs, distributor cap (if equipped), then connect the wires to the spark plugs as tagged during removal.
- Retighten the lower intake manifold, as outlined in this section.
- Install the engine into the vehicle.
- Fill the engine cooling system and crankcase to the proper levels with the correct types of fluids.
- Connect the negative battery cable, then start the engine and check for proper operation.
CLEANING AND INSPECTION
See Figures 5, 6 and 7
- Clean the crankshaft with solvent and a brush. Clean the oil passages with a brass brush, then blow them out with compressed air.
- Inspect the crankshaft for obvious damage or wear. Check the main and connecting rod journals for cracks, scratches, grooves or scores. Inspect the crankshaft oil seal surfaces for nicks, sharp edges or burrs that could damage the oil seal or cause premature seal wear.
- If the crankshaft passes a visual inspection, check journal runout using a dial indicator. Support the crankshaft in V-blocks, then check runout as shown. Compare to the specifications shown at the end of this section.
- Measure the main and connecting rod journals for wear, out-of-roundness or taper, using a micrometer. Measure in at least 4 places around each journal and compare your findings with the journal diameter specifications.
- If the crankshaft fails any inspection for wear or damage, it must be reground or replaced.
See Figures 8 and 9
The following procedure requires the use of Plastigage® or a micrometer set consisting of inside and outside micrometers, and a dial indicator.
- Inspect the bearings for scoring, chipping or other wear.
- Inspect the crankshaft journals as detailed in the Cleaning and Inspection procedure.
- If the crankshaft journals appear usable, clean them and the bearing shells until they are completely free of oil. Blow any oil from the oil hole in the crankshaft.
To check the crankshaft/rod bearing clearances using a micrometer, perform the following procedures:
- Set the crankshaft on V-blocks. Using a dial indicator set on the center bearing journal, check the crankshaft runout. Repair or replace the crankshaft if out of specification.
- Using an outside micrometer, measure the crankshaft bearing journals for diameter and out-of-round conditions; if necessary, regrind the bearing journals.
- Install the bearings and caps, then torque the nuts/bolts to specifications. Using an inside micrometer, check the bearing bores in the engine block. If out of specification, regrind the bearing bores to the next largest oversize.
- The difference between the two readings is the bearing clearance. If out of specification, inspect for the cause and repair as necessary.
- To inspect the main bearing surfaces, using the Plastigage® method, perform the following procedures:
NOTE: The journal surfaces and bearing shells must be completely free of oil to get an accurate reading with Plastigage®.
- Place a strip of Plastigage® or equivalent gauging material, lengthwise along the bottom center of the lower bearing shell, then install the cap with the shell and torque the connecting rod nuts or main cap bolts to specification.When the Plastigage® material is installed on the bearing surfaces, DO NOT rotate the crankshaft.
- Remove the bearing cap with the shell. The flattened Plastigage® will either be sticking to the bearing shell or the crankshaft journal.
- Using the printed scale on the Plastigage® package, measure the flattened material at its widest point. The number on the scale that most closely corresponds to the width of the Plastigage® indicates the bearing clearance in thousandths of an inch or hundredths of a millimeter.
- Compare your findings with the bearing clearance specification. If the bearing clearance is excessive, the bearing must be replaced or the crankshaft must be ground and the bearing replaced.NOTE: Bearing shell sets over standard size are available to correct excessive bearing clearance.
- After clearance measurement is completed, be sure to remove the Plastigage® from the crankshaft and/or bearing shell.
- For final bearing shell installation, make sure the connecting rod and rod cap and/or cylinder block and main cap bearing saddles are clean and free of nicks or burrs. Install the bearing shells in the bearing saddles, making sure the shell tangs are seated in the notches.
NOTE: Be careful when handling any plain bearings. Your hands and the working area should be clean. Dirt is easily embedded in the bearing surface and the bearings are easily scratched or damaged.