REMOVAL & INSTALLATION
See Figures 1, 2 and 3
- Remove the fuel pump and oil filter.
- Remove the crankshaft pulley and vibration damper.
- Remove the front cover and crankshaft gear.
- Invert the engine on the work stand. Remove the clutch pressure plate and disc (manual shift transmission). Remove the flywheel and engine rear cover plate. Remove the oil pan and gasket. Remove the oil pump.
- Make sure all bearing caps (main and connecting rod) are marked so that they can be installed in their original locations. Turn the crankshaft until the connecting rod from which the cap is being removed is down, and remove the bearing cap. Push the connecting rod and piston assembly up into the cylinder. Repeat this procedure until all the connecting rod bearing caps are removed.
- Remove the main bearings caps.
- Carefully lift the crankshaft out of the block so that the thrust bearing surfaces are not damaged. Handle the crankshaft with care to avoid possible fracture to the finished surfaces.
- Remove the rear journal seal from the block and rear main bearing cap.
- Remove the main bearing inserts from the block and bearing caps. Keep them in order if they are to be reused
- Remove the connecting rod bearing inserts from the connecting rods and caps. Keep them in order if they are to be reused
- If the crankshaft main bearing journals have been refinished to a definite undersize, install the correct undersize bearings. Be sure the bearing inserts and bearing bores are clean. Foreign material under the inserts will distort the bearing and cause a failure.
- Place the upper main bearing inserts in position in the bores with the tang fitting in the slot. Be sure the oil holes in the bearing inserts are aligned with the oil holes in the cylinder block.
- Install the lower main bearing inserts in the bearing caps.
- Clean the rear journal oil seal groove and the mating surfaces of the block and rear main bearing cap.
- Dip the lip-type seal halves in clean engine oil. Install the seals in the bearing cap and block with the undercut side of the seal toward the front of the engine.
This procedure applies only to engines with two piece rear main bearing oil seals. Those having one piece seals will be installed after the crankshaft is in place.
- Carefully lower the crankshaft into place. Be careful not to damage the bearing surfaces.
- Install all the bearing caps except the thrust bearing cap (no. 3 bearing on all except the 3.9L engine which use the no. 5 as the thrust bearing). Be sure the main bearing caps are installed in their original locations. Tighten the bearing cap bolts to specifications.
- Install the thrust bearing cap with the bolts finger-tight.
- 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. Tighten the cap bolts to specifications.
Check the crankshaft end-play using the following procedures:
- Force the crankshaft toward the rear of the engine.
- Install a dial indicator (tools D78P-4201-F,-G or equivalent) so that the contact point rests against the crankshaft flange and the indicator axis is parallel to the crankshaft axis.
- Zero the dial indicator. Push the crankshaft forward and note the reading on the dial.
- If the end play exceeds the wear limit listed in the Crankshaft and Connecting Rod Specifications chart, replace the thrust bearing. If the end play is less than the minimum limit, inspect the thrust bearing faces for scratches, burrs, nicks, or dirt. If the thrust faces are not damaged or dirty, then they probably were not aligned properly. Lubricate and install the new thrust bearing and align the faces.
- On 3.9L engines with one piece rear main bearing oil seal, coat a new crankshaft rear oil seal with oil and install using Tool T65P-6701-A or equivalent. Inspect the seal to be sure it was not damaged during installation.
- Install new bearing inserts in the connecting rods and caps. Check the clearance of each bearing, following the procedure (18a through 18d).
- After the connecting rod bearings have been fitted, apply a light coat of engine oil to the journals and bearings.
- Turn the crankshaft throw to the bottom of its stroke. Push the piston all the way down until the rod bearing seats on the crankshaft journal.
- Install the connecting rod cap. Tighten the nuts to specification.
- After the piston and connecting rod assemblies have been installed, check the side clearance with a feeler gauge between the connecting rods on each connecting rod crankshaft journal. Refer to Crankshaft and Connecting Rod specifications chart in this section.
- Install the timing chain and sprockets or gears, cylinder front cover and crankshaft pulley and adapter, following steps under Cylinder Front Cover and Timing Chain Installation in this section.
CHECKING MAIN BEARING CLEARANCES
See Figure 4
- Place a piece of Plastigauge® or its equivalent, on bearing surface across full width of bearing cap and about 1 / 4 in. (6mm) off center.
- Install cap and tighten bolts to specifications. Do not turn crankshaft while Plastigauge® is in place.
- Remove the cap. Using Plastigauge® scale, check width of Plastigauge® at widest point to get the minimum clearance. Check at narrowest point to get maximum clearance. Difference between readings is taper of journal.
- If clearance exceeds specified limits, try a 0.001 in. (0.0254mm) or 0.002 in. (0.051mm) undersize bearing in combination with the standard bearing. Bearing clearance must be within specified limits. If standard and 0.002 in. (0.051mm) undersize bearing does not bring clearance within desired limits, refinish crankshaft journal, then install undersize bearings.
CRANKSHAFT CLEANING & INSPECTION
Handle the crankshaft carefully to avoid damage to the finished surfaces.
- Clean the crankshaft with solvent, and blow out all oil passages with compressed air. On the 3.9L engine, clean the oil seal contact surface at the rear of the crankshaft with solvent to remove any corrosion, sludge or varnish deposits.
- Use crocus cloth to remove any sharp edges, burrs or other imperfections which might damage the oil seal during installation or cause premature seal wear.
Do not use crocus cloth to polish the seal surfaces. A finely polished surface may produce poor sealing or cause premature seal wear.
- Inspect the main and connecting rod journals for cracks, scratches, grooves or scores.
- Measure the diameter of each journal at least four places to determine out-of-round, taper or undersize condition.
- Inspect the pilot bearing (manual transmissions,) when used, for roughness, evidence of overheating or loss of lubricant. Replace if any of these conditions are found.
BREAK-IN PROCEDURE 1 / 2 hour. Road test the car, and check again for leaks.
Start the engine, and allow it to run at low speed for a few minutes, while checking for leaks. Stop the engine, check the oil level, and fill as necessary. Restart the engine, and fill the cooling system to capacity. Check and adjust the ignition timing. Run the engine at low to medium speed (800-2500 rpm) for approximately
Some gasket manufacturers recommend retorquing the cylinder head(s) due to the composition of the head gasket. Follow the directions in the gasket set.