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

Pistons and Connecting Rods

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IDENTIFICATION



See Figures 1, 2 and 3

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Fig. Fig. 1: Identification and positioning characteristics for the 2.2L and 2.5L naturally aspirated engines



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Fig. Fig. 2: Identification and positioning characteristics for the 2.2L and 2.5L turbocharged engines



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Fig. Fig. 3: The arrow stamped in the top of the piston should point toward the front of the engine

The pistons used in the 2.2L and 2.5L except Premier engines have notches in them to indicate the proper installed position. The notch faces the front of the engine, when installed. Connecting rods have markings to indicate proper assembly of the rod to the cap.

2.6L engines have arrows on the pistons. These arrows must face front when installed in the engine. The connecting rods are numbered for easy identification.

The pistons in the 2.5L Premier engines are equipped with the marking "FRT'' and an arrow, which should point toward the front of the engine when installed.

This procedure requires removal of the cylinder head and oil pan. It is much easier to perform this work with the engine removed from the vehicle and mounted on a stand. These procedures require certain hand tools which may not be in your tool box. A cylinder ridge reamer, a numbered punch set, piston ring expander, snapring tools and piston installation tool (ring compressor) are all necessary for correct piston and rod repair.

REMOVAL



All Engines

See Figures 4, 5, 6, 7 and 8

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Fig. Fig. 4: Use rubber hose over the connecting rod studs to protect the crankshaft and cylinders



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Fig. Fig. 5: Carefully tap the piston out of the bore using a wooden dowel- except Premier



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Fig. Fig. 6: An exploded view of a common connecting rod and piston assembly



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Fig. Fig. 7: If the connecting rod and bearing cap are not already matchmarked, use a steel stamp and hammer to do so



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Fig. Fig. 8: Label the pistons if they are to be reused so that they can be installed in their original positions

  1. Remove the cylinder head, following correct procedures listed earlier in this section.
  2.  
  3. Remove the oil pan, following correct procedures listed earlier in this section.
  4.  
  5. For 2.2L Turbo III and 2.5L except Premier engines, remove the balance shafts and carrier. For more information, refer to the correct procedure earlier in this section.
  6.  
  7. Note the identification of the pistons, as described earlier in the identification section of the piston and connecting rod procedures.
  8.  
  9. The connecting rods are marked to indicate which surface faces front, but the bearing caps should be matchmarked with numbers (front to rear) before disassembly. Use a marking punch and a small hammer; install the number over the seam of the rod and cap so that each piece will be reused in its original location.
  10.  
  11. Remove the connecting rod cap bolts, pull the caps off the rods, and place them on a bench in order.
  12.  
  13. Inspect the upper portions of the cylinder (near the head) for a ridge formed by ring wear. If there is a ridge, it must be removed by first pushing the piston down in the cylinder and then covering the piston top completely with a clean rag. Use a ridge reamer to remove metal at the lip until the cylinder is smooth. If this is not done, the rings will be damaged during piston removal.
  14.  
  15. Once the ridges have been removed, the pistons and rods may be pushed upward and out of the cylinders. Place pieces of rubber tubing over the rod bolts to protect the cylinder walls. Use a piece of wood or a hammer handle under the piston to tap it upward. If you're working under an engine that's still installed in the vehicle (with the crankshaft still in position) turn the crankshaft until the crankpin for each cylinder is in a convenient position. Be careful not to subject the piston and/or rod to heavy impact and do not allow the piston rod to damage the cylinder wall on the way out. The slightest nick in the metal can cause problems after reassembly.
  16.  

CLEANING & INSPECTION



All Engines

See Figures 9, 10, 11, 12 and 13

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Fig. Fig. 9: Clean the piston grooves using a ring groove cleaner-all engines



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Fig. Fig. 10: You can use a piece of an old ring to clean the ring grooves, but be CAREFUL the ring is sharp-all engines



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Fig. Fig. 11: Measure the piston's outer diameter using a micrometer- except Premier



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Fig. Fig. 12: A telescoping gauge is the best way to measure in the cylinder bore



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Fig. Fig. 13: Use the telescoping gauge to measure the cylinder bore diameter in the six directions shown

  1. Clean the pistons, rings and rods in parts solvent with a bristle brush. Do not use a wire brush, even to remove heavy carbon. The metal may be damaged.
  2.  
  3. Measure the bore of the cylinder at 3 levels and in 2 dimensions (fore-and-aft and side-to-side). That's six measurements for each cylinder. By comparing the 3 vertical readings, the taper of the cylinder can be determined and by comparing the front-rear and left-right readings the out-of-round can be determined. The block should be measured: at the level of the top piston ring at the top of piston travel; in the center of the cylinder; and at the bottom of the cylinder bore. The measurements are located in the specification charts in this section.
  4.  
  5. If the cylinder bore is not within specification for taper and out-of-round, or the wall is scored or scuffed, according to Chrysler the block must be replaced with a new one. However, in most cases it is possible to have the cylinders bored oversize to correct the problem. Under these circumstances, the block should be taken to a machine shop for proper boring by a qualified machinist using the specialized equipment required.
  6.  

If the cylinder is bored, oversize pistons and rings must be installed. Since all pistons must be the same size (for correct balance within the engine) ALL cylinders must be re-bored if any one is out of specification.

  1. Even if the cylinders do not need to be bored, they should be fine honed for proper break-in by a qualified machine shop. A de-glazing tool may be used in a power drill to remove the glossy finish on the cylinder walls. Use only the smooth stone type, not the beaded or bottle-brush type.
  2.  
  3. The cylinder head top deck (gasket surface) should be inspected for warpage. Run a straightedge along all four edges of the block, across the center, and diagonally. For the standard warpage value, refer to the specification charts in this section.
  4.  
  5. The rings should be removed from the pistons with a ring expander. Keep all rings in order and with the piston from which they were removed. The rings and piston ring grooves should be cleaned thoroughly with solvent and a brush as deposits will alter readings of ring wear. The piston ring grooves should also be cleaned with a groove cleaning tool or a piece of piston ring as shown in the illustrations.
  6.  
  7. Before any measurements are begun, visually examine the piston for any signs of cracks, particularly in the skirt area, or for scratches in the metal. Anything other than light surface scoring disqualifies the piston from further use. The metal will become unevenly heated and the piston may break apart during use.
  8.  
  9. Piston diameter should be measured at the skirt, at right angles to the piston pin. Compare either with specified piston diameter or subtract the diameter from the cylinder bore dimension to get clearance, depending upon the information in the specifications. If clearance is excessive, the piston should be replaced. If a new piston still does not produce piston-to-wall clearance within specifications, use an oversize piston and bore out the cylinder accordingly. Refer to the specification charts for the specific values for the various engines.
  10.  
  11. Ring end-gap must be measured for all 3 rings in the cylinder by using a piston top (upside down) to press the ring squarely into the top of the cylinder. First wipe the cylinder bore clean. The rings must be at least 0.63 in. (16mm) from the bottom of the bore. Use a feeler gauge to measure the end-gap and compare it with specifications.If cylinder bore wear is very slight, you may use new rings to bring the end-gap to specification without boring the cylinder.
  12.  

For piston ring specifications, refer to the Piston and Ring Specification chart in this section.

  1. Compression ring side clearance should be measured by using a ring expander to put cleaned rings back in their original positions on the pistons. Measure side clearance on one side by attempting to slide a feeler gauge of the thickness specified between the ring and the edge of the ring groove. If the gauge will not pass into the groove, the ring may be re-used. If the gauge will pass, but a gauge of slightly greater thickness representing the wear limit will not, the piston may be re-used, but new rings must be installed.
  2.  
  3. The connecting rods must be free from wear, cracking and bending. Visually examine the rod, particularly at its upper and lower ends. Look for any sign of metal stretching or wear. The piston pin should fit cleanly and tightly through the upper end, allowing no side-play or wobble. The bottom end should also be an exact half-circle, with no deformity of shape. The bolts must be firmly mounted and parallel.The rods may be taken to a machine shop for exact measurement of twist or bend.
  4.  
  5. If removal of the pistons from the connecting rods is necessary or desired, have the pins pressed out and the new pins heated and pressed back in by a qualified automotive machine shop. This procedure requires extreme heat and pressures which are not available to the general mechanic without the special tools needed.
  6.  

RIDGE REMOVAL & HONING



Ridge Removal

See Figure 14

Inspect the upper portions of the cylinder (near the head) for a ridge formed by ring wear. If there is a ridge, it must be removed by first shifting the piston down in the cylinder and then covering the piston top completely with a clean rag. Use a ridge reamer to remove metal at the lip until the cylinder is smooth. If this is not done, the rings will be damaged during removal of the piston.



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Fig. Fig. 14: Removing the ridge from the cylinder bore using a ridge cutter- except Premier

Honing

See Figures 15 and 16

Before honing the cylinders, stuff plenty of clean shop towels under the bores and over the crankshaft (if still in the engine) to keep the abrasive materials from entering the crankcase area.

  1. Used carefully, the cylinder bore resizing hone C-823 equipped with 220 grit stones, or equivalent, is the best tool for this job. In addition to deglazing, it will reduce taper and out-of-round as well as removing light scuffing, scoring or scratches. Usually a few strokes will clean up a bore and maintain the required limits.
  2.  
  3. Deglazing of the cylinder walls may be done using a cylinder surfacing hone (or equivalent), Tool C-3501, equipped with 280 grit stones (C-3501-3810) if the cylinder is already straight and round. 20-60 strokes depending on the bore condition will be sufficient to provide a satisfactory surface. Inspect the cylinder walls after each 20 strokes. using a light honing oil available from an automotive parts store.
  4.  

Do not use engine or transaxle oil, mineral spirits or kerosene.

  1. Honing should be done by moving the hone up and down fast enough to get a cross-hatch pattern. When hone marks intersect at 50-60°, the cross-hatch angle is most satisfactory for proper seating of the rings.
  2.  



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Fig. Fig. 15: Using a ball type cylinder hone is an easy way to hone the cylinder bore- except Premier



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Fig. Fig. 16: A properly cross-hatched cylinder bore

  1. A controlled hone motor speed between 200-300 rpm is necessary to obtain the proper cross-hatch angle. The number of up and down strokes per minute can be regulated to get the desired 50-60° angle. Faster up and down strokes increase the cross-hatch angle.
  2.  
  3. After honing, it will be necessary to clean the block to remove all traces of abrasive.
  4.  


WARNING
Be sure that all abrasive is removed from the engine parts after honing. It is recommended that a solution of soap and hot water be used with a brush and the parts then thoroughly dried. The bore is considered clean when it can be wiped with a white cloth and the cloth remains clean. Oil the bores after cleaning to prevent rust.

PISTON PIN REPLACEMENT



Except 2.2L Turbo III and 2.5L Turbo I Engines

The piston pins in all of these engines are press-fit into the piston/connecting rod assemblies. The piston pin must be heated up to an extreme temperature (often as high as 1500°F/815°C or higher) and then the pin must be pressed into the piston and connecting rod with a special press. Therefore, because of the special machinery and specific skills needed to either remove the old piston pin or to install the new piston pin, the piston, connecting rod and piston pin should be taken to a qualified machine shop.

2.2L Turbo III and 2.5L Turbo I Engines

See Figures 17, 18 and 19

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Fig. Fig. 17: Unlike all other engines which utilize interference fit piston pins, the 2.2L Turbo III and 2.5L Turbo I engines use full floating piston pins that use lockrings for retention



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Fig. Fig. 18: Remove the lockring from the piston with a small prytool through the notch



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Fig. Fig. 19: When installing the piston to the connecting rod, make sure to position the piston valve clearance notches on the same side as the connecting rod oil squirt hole

The turbocharged engine piston/pin/connecting rod assemblies should not be disassembled unless a malfunction is present or a damaged assembly component is to be replaced.


CAUTION
Approved safety glasses must be worn during piston lockring removal or installation to prevent possible injury from flying parts.

  1. Carefully remove the piston pin lockrings from the piston using a small prytool in the removal notch.
  2.  
  3. Discard the used lockring.
  4.  
  5. Following lockring removal, attempt to slide the pin out of the piston. If the pin does not slide freely by hand, check for a burr on the outer edge of the lockring groove. If a burr is present, carefully scrape the burr away with a knife or other hand tool, being careful not to damage the lockring retaining groove.
  6.  
  7. Slide the piston pin out to complete disassembly.
  8.  
  9. Inspect the components, discard damaged or excessively worn parts.
  10.  

If a new piston is being installed, a new piston pin should also be installed.

To assemble:
  1. Two different lockrings are used for the turbocharged engines. Consult the Service Note, provided with the lockring service package, to select the correct lockrings from the package for your application.
  2.  
  3. Careful install one new lockring with the gap toward the piston top in the lock ring groove. Do not reinstall the used lockrings.
  4.  
  5. Position the connecting rod and piston together. Make sure that the positioning markings on the connecting rod and piston agree. Lightly lubricate the piston pin, then slide it into the piston and connecting rod.
  6.  
  7. Install the second new lockring with the gap toward the piston top in the lockring groove. Use a small prytool, if necessary.
  8.  


WARNING
Both lockrings must be FULLY SEATED in the lockring grooves, otherwise engine failure will occur.

  1. Check the piston pin end-play movement between the lockrings in the assembly. The piston pin end-play specifications are as follows:

    2.5L Turbo I-new part, 0.000-0.035 in. (0.00-0.88mm)
     
    2.5L Turbo I-used component wear limit, 0.047 in. (1.20mm)
     
    2.2L Turbo III-new part, 0.0015-0.0400 in. (0.04-1.02mm)
     
    2.2L Turbo III-used component wear limit, 0.047 in. (1.20mm)
     

  2.  

PISTON RING REPLACEMENT



See Figures 20, 21, 22, 23, 24, 25, 26, 27 and 28

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Fig. Fig. 20: Use a ring expander tool to remove the piston rings



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Fig. Fig. 21: Checking the ring-to-ring groove clearance



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Fig. Fig. 22: Most rings are marked to show which side should face up



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Fig. Fig. 23: Piston ring placement



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Fig. Fig. 24: Install the 2 oil ring side rails by hand



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Fig. Fig. 25: Position the piston rings gaps as shown



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Fig. Fig. 26: When installing the piston rings on the 2.5L Premier engine, use the markings on the rings for position identification, as shown



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Fig. Fig. 27: The piston rings used in 2.6L engines have different cross-sections, which can be used for identification purposes



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Fig. Fig. 28: Exploded view of the piston rings on the pistons for 2.5L Premier engines

  1. Use a ring expander to remove the old rings from the pistons. Chances are that new piston rings will be used upon installation so it doesn't matter if the rings break during disassembly. Be careful though, the broken ring edges are extremely sharp. If the old piston rings are to be reused, be careful when removing the old rings and only expand them far enough to remove them from the piston.
  2.  
  3. Clean the piston and ring grooves. Refer to the previous cleaning procedures.
  4.  

To assemble:
  1. The No. 1 and No. 2 piston rings have a different cross-section. Install the rings with manufacturers mark and size mark facing up (toward the top of the piston).
  2.  

Install the pistons rings in the following order: a) oil ring expander, b) upper oil ring side rail, c) lower oil ring side rail, d) No. 2 intermediate (compression) piston ring, e) No. 1 upper (compression) piston ring.

  1. Install the oil ring expander by hand into its groove (bottom groove).
  2.  
  3. Install the upper side rail first, then the lower side rail by placing one end between the piston ring groove and the expander ring. Hold the end firmly while pressing the portion of the ring to be installed down (working along the side rail) until the ring is in position.
  4.  

Do not use a piston ring expander for the oil expander ring or either of the 2 side rail rings.

  1. Use a piston ring expander tool to install the No. 2 intermediate compression ring, then the No. 1 piston compression ring.
  2.  
  3. Position the piston ring end-gaps as shown in the illustration.
  4.  
  5. Position the oil ring expander gap at least 45° from the side rail gaps, but NOT on the piston pin center or on the thrust direction.
  6.  

CONNECTING ROD BEARINGS



Out-of-Vehicle Replacement

See Figure 29

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Fig. Fig. 29: A notch on the connecting rod bearing surface matches a groove on the insert

  1. Remove the connecting rod and piston assemblies from the engine, as described earlier in this section.
  2.  
  3. Remove the old bearings from the connecting rod large end and the connecting rod bearing cap.
  4.  
  5. Clean and inspect the connecting rod and bearing cap. Refer to the procedures found previously.
  6.  
  7. Install the new bearings into the bearing cap and connecting rod large end. To install the bearings, push the bearings into the cap or rod so that the bearing is flush with the flat cap/rod mounting surface. The side of the bearing with the groove tang goes on the same side of the rod or cap that has the groove in it. The tang sides of the upper and lower bearings are installed on the same side of the rod journal.
  8.  
  9. Coat the bearing surface with assembly lube. Engine oil can also be used, but it is recommended that assembly lube be used to help the break-in of the bearings.
  10.  
  11. Install the piston/connecting rod assemblies back into the engine.
  12.  

In-Vehicle Replacement

ALL ENGINES



See Figures 29 and 30

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Fig. Fig. 30: Check the connecting rod bolts for necking (stretching)-2.2L and 2.5L except Premier engines

This procedure can be accomplished with either the engine in the vehicle with the pistons and crankshaft installed or with the pistons removed from the engine.

  1. If the bearings need to replaced while the engine is in the vehicle, disconnect the negative battery cable. Raise and safely support the vehicle on jackstands. Removal of the oil pan will be necessary, refer to the procedure in this section.
  2.  
  3. For 2.2L Turbo III engines and 2.5L except Premier engines, remove the balance shafts and carrier, as described earlier in this section.
  4.  
  5. Matchmark the bearing caps with their cylinder number for ease of assembly.
  6.  
  7. Perform the following procedure to each connecting rod, one at a time.
    1. Rotate the crankshaft until the connecting rod being worked on is at the lowest point in its stroke.
    2.  
    3. Remove the bearing cap retaining nuts and remove the bearing cap from the crankshaft.
    4.  

  8.  

Use pieces of rubber hose over the connecting rod bolts to prevent scratching the crankshaft bearing surfaces or cylinder walls.

    1. Using a piece of wood or a hammer handle, tap the piston up into the engine until the connecting rod bottom end comes off of the crankshaft journal.
    2.  
    3. Using a small punch or prytool push the old bearings out of the bearing cap and the end of the connecting rod large end.
    4.  
    5. Using a micrometer check the crankshaft journal for out-of-round and taper. The limits for either are shown in the Crankshaft Specifications chart in this section. If the crankshaft exhibits too much taper or out-of-round it must be replaced or machined by a machine shop. Undersized bearings are available in case the crankshaft needs machining.
    6.  


Do not lubricate the bearings at this time. First the bearing clearance must be checked using Plastigage® and if the bearings are lubricated, it will adversely affect the Plastigage® process.

    1. Install the new bearings into the cap and rod end. The bearing shells must be installed with the tangs inserted into the machined grooves in the rods and caps.
    2.  


Install the bearings in pairs. Do not use a new bearing half with an old bearing half. Do not file the rods or bearing caps.

    1. Clean the crankshaft journal of all oil, dirt or all other contaminants.
    2.  
    3. Pull the piston back down until the connecting rod is once again seated on the crankshaft journal.
    4.  
    5. Apply the Plastigage® to the crankshaft journal. Refer to the Plastigage® procedures following this procedure before commencing.
    6.  
    7. Install the bearing cap onto the crankshaft journal. When the bearing caps are installed, install the cap with the tangs on the same side as the rod.
    8.  
    9. Tighten the connecting rod nuts to specifications (shown in the Torque Specifications chart in the beginning of this section).
    10.  


Do not turn the crankshaft while the Plastigage® is being used. Refer to the Plastigage® procedures following this procedure.

    1. Remove the bearing caps again. Using the gauge which came with the Plastigage® read the clearance of the connecting rod bearing. The connecting rod bearing clearances are shown in the Crankshaft and Connecting Rod Specifications chart earlier in this section. If the connecting rod bearing clearance is too great, the crankshaft must be machined by a machine shop and undersized bearings used.
    2.  
    3. Clean the Plastigage® off of the crankshaft journal or connecting rod bearings.
    4.  
    5. The rod bolts must be examined before reuse. If the threads are necked down (stretched) the bolts will have to be replaced with new bolts. Necking can be checked by holding a ruler or straightedge against the threads. If all of the threads do not contact the scale, the bolt is exhibiting necking.
    6.  
    7. If the clearance is within specification, lubricate the connecting rod bearings with assembly lube or clean engine oil (assembly lube is preferred by the manufacturer). Install the connecting rod bearing cap onto the crankshaft again. Tighten the cap to the designated torque, as described previously.
    8.  

  1. Repeat the procedure with all of the other connecting rods, one at a time.
  2.  
  3. If the pistons and crankshaft are removed from the engine, install the crankshaft and pistons to the engine block before tightening the bearing caps and checking for clearance. However, the new bearings can be inserted into the connecting rod ends and bearing caps prior to installation.
  4.  
  5. For 2.2L Turbo III and 2.5L engines, install the balance shafts and carrier.
  6.  
  7. Install the oil pan, lower the vehicle and connect the negative battery cable.
  8.  
  9. Fill the engine with the proper amount of oil.
  10.  

Checking Connecting Rod Bearing Clearance With Plastigage®

See Figure 31

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Fig. Fig. 31: Use the gauge supplied with the Plastigage® to check the bearing clearance

The engine crankshaft and connecting rod bearing clearances can be determined by the use of Plastigage® or a similar product. The following is the recommended procedure for the use of Plastigage®:

  1. Rotate the crankshaft until the connecting rod boss to be checked is at the bottom of its stroke.
  2.  
  3. With the connecting rod and the connecting rod bearing cap removed from the crankshaft, remove the oil film from the surface to be checked. Plastigage® is soluble in oil.
  4.  
  5. Place a piece of Plastigage® across the entire width of the bearing shell in the bearing cap approximately 1 / 4 in. (6.35mm) off center and away from the oil hole. In addition, suspect areas can be checked by placing Plastigage® in the suspect area.
  6.  
  7. Before assembling the rod bearing cap with the Plastigage® in place, the crankshaft must be rotated until the connecting rod being checked starts moving toward the top of the engine. Only then should the cap be assembled and tightened to specifications.
  8.  

Do not rotate the crankshaft while assembling the cap or the Plastigage® may be smeared, giving inaccurate results.

  1. Remove the bearing cap and compare the width of the flattened Plastigage® with the metric scale provided on the package. Locate the band closest to the same width. This band shows the amount of clearance in thousandths of a millimeter. Differences in readings between the ends indicate the amount of taper present. Record all readings taken.
  2.  

Plastigage® generally is accompanied by 2 scales. One scale is in inches, the other is a metric scale.

  1. Plastigage® is available in a variety of clearance ranges. The 0.001-0.003 in. (0.025-0.076mm) is usually the most appropriate for checking engine bearing proper specifications.
  2.  
  3. Clean the Plastigage® from the connecting rod journal or from the connecting rod bearing shell.
  4.  

INSTALLATIONSee Figure 32





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Fig. Fig. 32: Always make sure to tighten the connecting rod attaching nuts with a torque wrench

All Engines
  1. Have a machine shop reassemble the pistons to the connecting rods, unless servicing the 2.2L Turbo III or 2.5L Turbo I engines. If repairing either of these engines, assemble the pistons, connecting rods and piston pins, as described earlier in this section.
  2.  


WARNING
Do not use a piston ring expander for the oil expander ring or either of the 2 side rail oil rings.

  1. Install the rings onto the pistons as follows:
    1. The No. 1 and No. 2 piston rings have a different cross section. Install the rings with manufacturer's mark and size mark facing up (toward the top of the piston).
    2.  

  2.  

Install the pistons rings in the following order: a) oil ring expander, b) upper oil ring side rail, c) lower oil ring side rail, d) No. 2 intermediate (compression) piston ring, e) No. 1 upper (compression) piston ring.

  1. Install the oil ring expander by hand into its groove (bottom groove).
  2.  
  3. Install the upper side rail first, then the lower side rail by placing one end between the piston ring groove and the expander ring. Hold the end firmly while pressing the portion of the ring to be installed down (working along the side rail) until the ring is in position.
  4.  
  5. Use a piston ring expander tool to install the No. 2 intermediate compression ring, then the No. 1 piston compression ring.
  6.  
  7. Position the piston ring end-gaps as shown in the illustration.
  8.  
  9. Position the oil ring expander gap at least 45° from the side rail gaps, but NOT on the piston pin center or on the thrust direction.
  10.  

  1. All the pistons, rods and caps must be reinstalled in the correct cylinder. Make certain that all labels and stamped numbers are present and legible. Double check the piston rings; make certain that the ring gaps DO NOT line up.
  2.  
  3. Reinstall the protective rubber hose pieces on the connecting rod bolts.
  4.  
  5. Liberally coat the cylinder walls and the crankshaft journals with clean, fresh engine oil.
  6.  
  7. Install each piston/connecting rod into its respective cylinder bore one at a time as follows:
    1. Identify the front mark on each piston/connecting rod assembly and position the piston loosely in its cylinder with the marks facing the front (pulley end) of the motor.
    2.  

  8.  


WARNING
Failure to observe the applicable markings and the pistons' correct placements can lead to sudden engine failure.

    1. Install a ring compressor (piston installation tool) around one piston and tighten it gently until the rings are compressed almost completely.
    2.  
    3. Gently push down on the piston top with a wooden hammer handle or similar soft-faced tool and drive the piston into the cylinder bore. Once all 3 rings are within the bore, the piston will move with some ease.
    4.  



WARNING
If any resistance or binding is encountered during the installation, DO NOT apply excessive force. Tighten or adjust the ring compressor and/or reposition the piston. Brute force will break the ring(s) or damage the piston.

    1. From underneath, pull the connecting rod into place on the crankshaft. Remove the rubber hoses from the bolts. Check the rod cap to confirm that the bearing is present and correctly mounted.
    2.  
    3. At this time check the connecting rod bearing clearance. Refer to the connecting rod bearing instructions with Plastigage® for this procedure. After checking the clearance do not completely tighten the connecting rod bearing caps to their final torque yet.
    4.  
    5. If all of the bearing clearances are within specifications continue with this procedure. Otherwise the crankshaft or connecting rods will need to be either machined or replaced with new ones. If out of specification, have them checked by a reputable automotive machine shop.
    6.  
    7. Install the rod cap (observing the correct number and position) and its nuts. Leaving the nuts finger-tight will make installation of the remaining pistons and rods easier.
    8.  

  1. Assemble the remaining pistons in the same fashion, repeating Step 6.
  2.  
  3. With all the pistons installed and the bearing caps secured finger-tight, the retaining nuts may be tightened to their final setting. Refer to the Torque Specifications chart at the beginning of this section for the correct torque for the engine in your vehicle. For each pair of nuts, make 3 passes alternating between the 2 nuts on any given rod cap. The 3 tightening steps should each be about one third of the final torque. The intent is to draw each cap up to the crankshaft straight and under even pressure at the nuts.
  4.  
  5. Turn the crankshaft through several clockwise rotations, making sure everything moves smoothly and there is no binding. With the piston rods connected, the crank may be stiff to turn. Try to turn it in a smooth continuous motion so that any binding or stiff spots may be felt.
  6.  
  7. At this time, use a feeler gauge to measure the connecting rod side clearance. Refer to the specifications chart for the correct amount of side clearance allowed. If the side clearance is too great, the connecting rods will have to be replaced with new ones. If the side clearance to is too small, the connecting rods will have to be removed and machined by a reputable automotive machine shop.
  8.  
  9. For 2.2L Turbo III and 2.5L except Premier engines, install the balance shafts and carrier. For more information, refer to the procedure earlier in this section.
  10.  
  11. Reinstall the oil pan. Even if the engine is to remain apart for other repairs, install the oil pan to protect the bottom end and tighten the bolts to the correct specification; this eliminates one easily overlooked mistake during future reassembly.
  12.  
  13. If the engine is to remain apart for other repairs, pack the cylinders with crumpled newspaper or clean rags (to keep out dust and grit) and cover the top of the motor with a large rag. If the engine is on a stand, the whole block can be protected with a large plastic trash bag.
  14.  
  15. If no further work is to be performed, continue reassembly by installing the cylinder head, timing belt or chains, and all other components.
  16.  

 
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