Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Crankshaft and Main Bearings

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REMOVAL & INSTALLATION



See Figure 1



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Fig. Fig. 1: Always tighten the main bearing nuts with a torque wrench

Although the following procedure is presented as if the engine is removed from the vehicle and installed on an engine stand, it may also be possible to service the crankshaft when the engine is still installed in the vehicle.

All Engines

See Figures 2, 3, 4, 5 and 6

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Fig. Fig. 2: An exploded view of a common crankshaft and main bearing cap set-up-2.6 L engine shown, however the other engines are very essentially the same



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Fig. Fig. 3: If the bearing caps are not labeled already, use a stamp set to number the caps prior to removal-set the caps in order once they are removed to prevent mix-ups



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Fig. Fig. 4: The bearing halves are different depending on their installed positions-the grooved bearing shells are installed in the engine block, whereas the smooth halves are installed in the bearing caps



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Fig. Fig. 5: Make sure that the bearings are not cocked and that their edges are flush with either the engine block or bearing cap (depending on their installed position)



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Fig. Fig. 6: When installing the main bearing caps, check the bolts for stretching, or "necking'', with a straightedge or ruler, as shown

This is a general procedure which is applicable to all engines covered by this information. However, slight variations may arise; alter the procedure accordingly.

The crankshaft is supported in five main bearings. All upper bearing shells in the crankcase have oil grooves. All lower bearing shells are not equipped with oil grooves. Crankshaft end-play is controlled by the thrust bearing on the number 3 main bearing journal for all Chrysler engines and on main bearing journal No. 2 for the 2.5L Premier engine.

  1. Remove the engine from the vehicle and install it onto an engine stand.
  2.  
  3. Remove the upper end components (intake manifold, cylinder heads, timing belt and cover, etc.). Refer to the particular procedures in this section.
  4.  
  5. Remove the oil pan and oil pump. Refer to the particular procedure in this section.
  6.  
  7. Flip the engine upside-down on the engine stand.
  8.  
  9. Remove the rear oil seal retainer and seal as an assembly from the engine block. Refer to the particular procedure in this section.
  10.  
  11. If equipped, remove the balance shafts and carrier, as described earlier in this section.
  12.  

Bearing caps are not interchangeable and should be marked at removal to ensure correct reassembly.

  1. Release the crankshaft main bearing cap bolts evenly. Remove the lower bearing shells and identify them for ease of reassembly.
  2.  
  3. Remove the connecting rod bearing caps and push the pistons down into their respective cylinder bores. For more information, refer to the proper procedures earlier in this section.
  4.  
  5. Lift the crankshaft out and remove the upper crankshaft main bearing shells.
  6.  

To install:

Upper and lower bearing halves are NOT interchangeable. For except Premier engines, lower main bearing halves 1, 2, 4 and 5 are interchangeable and upper main bearing halves 1, 2, 4 and 5 are also interchangeable.

  1. Install the upper main bearing shells making certain the oil holes are in alignment, and the bearing tabs seat in the block tabs. All upper bearings have oil grooves. The crankshaft thrust bearing is installed in journal No. 3 for the 2.2L, 2.5L except Premier and 2.6L engines. The crankshaft thrust bearing is installed in journal No. 2 for the 2.5L Premier engine.
  2.  
  3. Wipe any oil from the crankshaft journals and bearing shells.
  4.  
  5. Set the crankshaft into the engine.
  6.  
  7. Cut pieces of Plastigage® to the same length as the width of the bearing and place a piece on each of the journals parallel with the journal axis.
  8.  
  9. Install the lower main bearing shells (without oil grooves) in the crankshaft bearing caps.
  10.  
  11. Install the main bearing caps carefully and tighten the bolts to the specified torque value, as shown in the Torque Specifications chart in the beginning of this section.
  12.  

Do not rotate crankshaft or the Plastigage® will be smeared.

  1. Carefully remove the bearing caps and measure the width of the various pieces of the Plastigage® at their widest points using the scale on the Plastigage® package. If the clearances are not within specifications, either different bearing shells will be needed or the crankshaft must be machined by a reputable automotive machine shop.
  2.  
  3. Wipe the Plastigage off of the crankshaft or bearing shell. Remove the crankshaft from its position in the engine.
  4.  
  5. Oil the bearings and journals. Reinstall the crankshaft to the engine.
  6.  
  7. Carefully install the bearing caps with the arrows toward the timing belt end.
  8.  
  9. Oil the bearing cap bolt threads, install and tighten the bolts progressively to the torque specification. On the 2.2L and 2.5L except Premier engines, tighten the crankshaft main bearing cap bolts first only finger-tight, then tighten them to 30 ft. lbs. (41 Nm) plus an additional 1 / 4 turn. On the 2.6L engine, tighten the crankshaft main bearing bolts to 58 ft. lbs. (79 Nm) in 3 even steps, such as 20 ft lbs. (27 Nm), 40 ft. lbs. (54 Nm) and 58 ft. lbs. (79 Nm). On the 2.5L Premier engine, tighten the main bearing bolts as follows:
    1. All of the main bearing bolts should be slightly loose.
    2.  
    3. Tighten the bolts of caps No. 1, No. 3, No. 4 and No. 5 to 40 ft. lbs. (54 Nm).
    4.  
    5. Retighten the bolts for caps No. 1, No. 3, No. 4 and No. 5 to 70 ft. lbs. (95 Nm).
    6.  
    7. Finally tighten the bolts for caps No. 1, No. 3, No. 4 and No. 5 to 80 ft. lbs. (108 Nm).
    8.  
    9. Push the crankshaft forward and backward. Push the crankshaft either toward the front or rear and hold it there while tightening the bolts for cap No. 2 to 40 ft. lbs. (54 Nm), then to 70 ft. lbs. (95 Nm), and finally to 80 ft. lbs. (108 Nm).
    10.  

  10.  
  11. Rotate the crankshaft to check for binding or any other problems.
  12.  
  13. Mount a dial indicator to the front of the engine, locating the probe on the nose of the crankshaft.
  14.  
  15. Move the crankshaft all the way to the rear of its travel.
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  17. Set the dial indicator to zero.
  18.  
  19. Move the crankshaft all the way to the front and read the dial indicator. Refer to the engine charts for the proper end-play specification.
  20.  
  21. Scrape clean or wire brush the gasket surface of the oil seal retainer to remove all lose material. Inspect the housing to ensure that the gasket surface is flat.
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  23. Clean the surface of all oil and residual dirt. Make sure all of the old gasket material is removed from any bolt holes or housing surfaces.
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  25. Set the retainer on a flat, hard, clean work surface with the inside face resting down. Install a new oil seal, as described earlier in this section.
  26.  
  27. Apply Mopar Silicone Rubber Adhesive Sealant® or the equivalent to the oil seal housing in a continuous bead of 0.120 in. (3mm) diameter or less, as shown. Be certain that the sealing material surrounds each mounting bolt hole. Excess material can easily be wiped off. The oil seal retainer should be installed and tightened to its specified torque within 10 minutes (still wet to the touch).
  28.  
  29. Apply a light coating of engine oil to the entire circumference of the oil seal lip.
  30.  
  31. Install the seal retainer onto the cylinder block. For more information, refer to the rear main oil seal procedures in this section.
  32.  
  33. Pull the pistons and connecting rods back up and install them onto the crankshaft, as described earlier in this section.
  34.  
  35. Install a new front oil seal. For more information, refer to the crankshaft, camshaft and intermediate shaft sprocket procedure in this section.
  36.  
  37. Install the oil pan, oil pump and related components. Refer to the procedures in this section.
  38.  
  39. Reassemble the engine and install it back into the vehicle.
  40.  

CLEANING & INSTALLATION



Clean all components in a solvent to remove oil, dirt or caked on grime.

The crankshaft main journals should be checked for excessive wear, taper and scoring. Limits of taper or out-of-round on any crankshaft journals are shown in the Engine Rebuilding Specification charts at the end of this section. Do not grind the thrust faces of No. 3 main bearing. Do not nick the crankshaft pin or bearing fillets. After grinding, remove all rough edges from the crankshaft oil holes and clean out all passages.

Crankshaft End-Play

See Figures 7 and 8

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Fig. Fig. 7: A dial gauge should be positioned as shown to measure crankshaft end-play



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Fig. Fig. 8: Carefully pry the shaft back and forth while reading the dial gauge for play

  1. Rotate the crankshaft to check for binding or any other problems.
  2.  
  3. Mount a dial indicator to the front of the engine, locating the probe on the nose of the crankshaft.
  4.  
  5. Pry the crankshaft all the way to the rear of its travel with a prybar.
  6.  
  7. Set the dial indicator to zero.
  8.  
  9. Move the crankshaft all the way to the front and back again while reading the dial indicator. Pry the crankshaft back and forth several times. The amount of variation measured by the dial indicator is the end-play. Refer to the engine charts for the proper end-play specification.
  10.  
  11. If end-play is not within specification, inspect the crankshaft thrust faces for wear. If no wear is evident, replace the thrust bearing and measure end-play again. If end-play is still not within specification, replace the crankshaft.
  12.  

Main Bearing Oil Clearance

Perform this procedure if only the crankshaft oil bearing clearance must be measured, otherwise refer to either the crankshaft removal and installation procedure or the crankshaft main bearing replacement procedure.

  1. Remove cap from the bearing to be checked. Using a clean, dry rag, thoroughly clean all oil from crankshaft journal and bearing insert.
  2.  

Plastigage® is soluble in oil; therefore, oil on the journal or bearing could result in erroneous readings.

  1. Place a piece of Plastigage® along the full width of the insert, reinstall cap, and torque to specifications.
  2.  
  3. Remove bearing cap, and determine clearance by comparing width of Plastigage® to the scale on Plastigage® envelope. Journal taper is determined by comparing width of the Plastigage® strip near its ends. Remove the Plastigage®, rotate the crankshaft 90 degrees and retest, to determine journal concentricity.
  4.  

Do not rotate crankshaft with Plastigage® installed.

  1. If the bearing insert and journal appear intact, and are within tolerances, no further main bearing service is required. Just make sure to oil the bearing and crankshaft journal surfaces thoroughly and reassemble caps to the specified torque. If the bearing or journal appear defective, the cause of failure should be determined before replacement.
  2.  

BEARING REPLACEMENT



See Figure 9



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Fig. Fig. 9: A roll-out pin can be fabricated from a cotter pin-simply bend it as shown

This procedure explains how to replace the crankshaft bearings without removing the crankshaft from the engine. If the crankshaft must be removed for some other reason, refer to the previous removal and installation procedure.

Use these procedures as a guide for all engines. Modify service steps, if required.

  1. Rod bearings can be installed when the pistons have been removed for servicing (rings etc.) or, in most cases, while the engine is still in the car. Bearing replacement, however, is far easier with the engine out of the car and disassembled.
  2.  
  3. For in-car service, remove the oil pan, oil pump, balance shafts and carrier (if equipped-2.2L Turbo III and 2.5L except Premier engines), spark plugs and front cover, as necessary.
  4.  
  5. Main bearings may be replaced while the engine is still in the car by "rolling'' them out and in.
  6.  
  7. A special roll-out pin is available from Chrysler (Tool C-3059), from automotive parts houses or can be fabricated from a cotter pin (refer to the illustration). The roll out pin fits in the oil hole of the main bearing journal on the crankshaft. When the crankshaft is rotated opposite the direction of the bearing lock tab, the pin engages the end of the bearing and rolls out the insert.
  8.  

Bearing caps are not interchangeable and should be marked at removal to ensure correct reassembly.

  1. Remove one main bearing cap and roll out the upper bearing insert, as follows:
    1. Insert the roll-out pin into the oil hole of the crankshaft main journal.
    2.  
    3. Slowly rotate the crankshaft clockwise, forcing the upper half of the bearing shell out of the engine block.
    4.  

  2.  
  3. Remove the bearing insert from the main bearing cap. Clean the inside of the bearing cap and crankshaft journal.
  4.  

Upper and lower bearing halves are NOT interchangeable. Lower main bearing halves 1, 2, 4 and 5 are interchangeable and upper main bearing halves 1, 2, 4 and 5 are also interchangeable. Only one main bearing should be selectively fitted while all other main bearing caps are properly tightened.

If servicing main bearing No. 3 (middle main bearing), make sure to install the thrust bearing (bearing with the folded over edges).

  1. Lubricate only the upper bearing shell with assembly lube or clean engine oil (assembly lube is preferred by the manufacturer) and roll the upper insert into position in the crankshaft main, make sure the lock tab is anchored in the groove of the main journal and the insert is not cocked. Remove the bearing roll-out tool.
  2.  


WARNING
Make sure to remove the roll-out pin tool, otherwise extensive crankshaft and/or engine block damage will occur.

  1. Check the main bearing oil clearance, as follows:
    1. Wipe any oil from the bottom half of the crankshaft journal and bearing shells.
    2.  
    3. Cut a piece of Plastigage® to the same length as the width of the bearing and place a piece on the journal parallel with the journal axis.
    4.  
    5. Install the lower main bearing shell (without oil grooves) dry in the crankshaft bearing cap.
    6.  
    7. Install the main bearing cap carefully and tighten the bolts to the specified torque value, as shown in the Torque Specifications chart in the beginning of this section.
    8.  

  2.  

Do not rotate crankshaft or the Plastigage® will be smeared.

    1. Carefully remove the bearing cap and measure the width of the Plastigage® at its widest point using the scale on the Plastigage® package; this is the minimum oil clearance for this journal. Measure the thinnest section of Plastigage® and subtract this number from the widest section, this is the amount of taper of the crankshaft journal or it indicates that the bearings may be slightly cocked. Double check that the bearings are mounted flush in their bores. If the clearances measured are not within specifications, either different bearing shells must be acquired or the crankshaft must be machined by a reputable automotive machine shop. Remove the crankshaft and inspect it with a micrometer, or have a reputable machine shop inspect it.
    2.  
    3. Wipe the Plastigage off of the crankshaft or bearing shell.
    4.  

  1. Oil the lower bearing half and lower half of the journal with assembly lube or clean engine oil (assembly lube is preferred by the manufacturer).
  2.  
  3. Install the lower bearing insert into the main cap. Lubricate it with assembly lube or engine oil as with the upper bearing, then install it on the engine. Make sure the main bearing cap is installed facing in the correct direction. Make sure the oil holes line up with those in the block and that the grooved bearing shell is located in the block (rather than in the cap). The thrust bearing (the bearing with folded up sides) must be installed in the No. 3 main.
  4.  
  5. Oil the bearing cap bolt threads. Check the cap bolts for "necking down''. This is a condition that would prevent the right size nut from being run down until it touches the cap or would cause some threads not to touch a straightedge run along the side of the bolt.
  6.  
  7. Tighten the crankshaft main bearing cap bolts until slightly looser than snug.
  8.  
  9. Repeat Steps 5 through 11 for all main bearings which are to be replaced (all of the bearings should be replaced at the same time).
  10.  
  11. Once all replacement bearings are installed, install and tighten the bolts progressively to the torque specification. On the 2.2L and 2.5L except Premier engines, tighten the crankshaft main bearing cap bolts first only finger-tight, then tighten them to 30 ft. lbs. (41 Nm) plus an additional 1/4 turn. On the 2.6L engine, tighten the crankshaft main bearing bolts to 58 ft. lbs. (79 Nm) in 3 even steps, such as 20 ft lbs. (27 Nm), 40 ft. lbs. (54 Nm) and 58 ft. lbs. (79 Nm). On the 2.5L Premier engine, tighten the main bearing bolts as follows:
  12.  
    1. All of the main bearing bolts should be slightly loose.
    2.  
    3. Tighten the bolts of caps No. 1, No. 3, No. 4 and No. 5 to 40 ft. lbs. (54 Nm).
    4.  
    5. Retighten the bolts for caps No. 1, No. 3, No. 4 and No. 5 to 70 ft. lbs. (95 Nm).
    6.  
    7. Finally tighten the bolts for caps No. 1, No. 3, No. 4 and No. 5 to 80 ft. lbs. (108 Nm).
    8.  
    9. Push the crankshaft forward and backward. Push the crankshaft either toward the front or rear and hold it there while tightening the bolts for cap No. 2 to 40 ft. lbs. (54 Nm), then to 70 ft. lbs. (95 Nm), and finally to 80 ft. lbs. (108 Nm).
    10.  

  13. Rotate the crankshaft to ensure that there is no binding. If binding, or other problems, are evident, the crankshaft should be completely removed from the engine and inspected for defects.
  14.  
  15. Mount a dial indicator to the front of the engine, locating the probe on the nose of the crankshaft.
  16.  
  17. Move the crankshaft all the way to the rear of its travel.
  18.  
  19. Set the dial indicator to zero.
  20.  
  21. Move the crankshaft all the way to the front and read the dial indicator. Refer to the engine charts for the proper end-play specification.
  22.  
  23. Install the components removed earlier. For more information, refer to the applicable procedures.
  24.  

BREAK-IN PROCEDURE



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 (800-2,500 rpm) for approximately 1 / 2 hour, and retighten the cylinder head bolts. Road test the car, and check again for leaks.

Some gasket manufacturers recommend not retightening the cylinder head(s) due to the composition of the head gasket. Follow the directions in the gasket set.

 
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