AutoZone 1992 Lexus SC400 4.0L MFI DOHC 8cyl | Repair Guides | Engine & Engine Rebuilding | Engine Mechanical | Crankshaft And Main Bearings | AutoZone.com

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    Toyota Tercel 1984-1994 Repair Guide

    Crankshaft and Main Bearings

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    REMOVAL & INSTALLATION



    See Figures 1, 2, 3 and 4

    1. Remove the engine assembly from the car, following procedures outlined earlier in this section. Mount the engine securely on a stand which allows it to be rotated.
    2.  
    3. Remove the timing belt and tensioner assemblies.
    4.  
    5. Turn the engine upside down on the stand. Remove the oil pan and the oil strainer.
    6.  



    Click image to see an enlarged view

    Fig. Fig. 1: On 3E and 3E-E engines, loosen the main bearing cap bolts using this sequence



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    Fig. Fig. 2: The caps should be marked as to their cylinder number and direction before removal

    1. Remove the oil pump.
    2.  
    3. Remove the clutch and pressure plate (M/T).
    4.  
    5. Remove either the flywheel (manual) or the drive plate (automatic).
    6.  
    7. Remove the rear end plate.
    8.  
    9. Remove the rear oil seal retainer.
    10.  
    11. Using a numbered punch set, mark each connecting rod cap with its correct cylinder number. Remove the rod caps and their bearings; keep the bearings with their respective caps.
    12.  
    13. Measure the crankshaft end-play (thrust clearance) before removing the crank. Attach a dial indicator to the end of the block and set the tip to bear on the front end of the crankshaft. With a small prytool, gently move the crankshaft back and forth and record the reading shown on the dial.
    14.  
    15. Maximum allowable end-play is 0.0118 in (0.30mm) on 3A and 3A-C engines and 0.012 in. (0.3mm) on 3E and 3E-E engines.
    16.  

    If the end-play is excessive, the thrust washers will need to be replaced as a set.

    1. Gradually loosen and remove the main bearing cap bolts in three passes. On 3E and 3E-E engines, loosen the bolts using the correct sequence. Remove just the bolts, leaving the caps in place.
    2.  
    3. When all the bolts are removed, use two bolts placed in the No. 3 bearing cap to wiggle the cap back and forth. This will loosen the cap and allow it (with the thrust washers) to be removed. Note and/or label the thrust washers as to their placement and position. If they are to be reused, they must be reinstalled precisely in their original positions.
    4.  
    5. Remove the remaining caps. Keep the caps in order and keep the bearing shells with their respective caps.
    6.  
    7. Lift the crankshaft out of the block. Be careful, the crankshaft is a moderately heavy component.
    8.  
    9. Remove the upper bearing shells from the block and place them in order with the corresponding bearing caps.
    10.  
    11. Check and measure the crankshaft and bearings according to the procedures found under Cleaning and Inspection later in this section.
    12.  

    To install:
    1. When reassembling, clean the bearing caps and journals in the block thoroughly. Coat the bearings with a liberal application of clean motor oil.
    2.  



    Click image to see an enlarged view

    Fig. Fig. 3: Always torque the bearing caps to specification



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    Fig. Fig. 4: Main bearing cap bolt tightening sequence on 3E and 3E-E engines

    1. Fit the upper bearings halves into the block and position the lower bearing halves in the bearing caps.
    2.  
    3. Place the crankshaft into the engine block, making sure it fits exactly into its mounts.
    4.  
    5. Install the upper thrust washers on the center main bearing with the oil grooves facing outward.
    6.  
    7. Install the main bearing caps and the lower thrust washers in the proper sequence. Make sure the arrows on the caps point towards the front (pulley end) of the motor.
    8.  
    9. Tighten the cap bolts to specification in three passes. On 3E and 3E-E engines, use the correct sequence.
    10.  
    11. Double check the end-play of the crankshaft by repeating the procedure described earlier.
    12.  
    13. Turn the crankshaft through one or two full clockwise rotations, making sure that it turns smoothly and evenly with no binding.
    14.  
    15. Attach the piston rods, following procedures given earlier in this section. Remember that the rod caps must be reinstalled in their original positions.
    16.  
    17. Install a new rear main oil seal into the retainer and install the retainer onto the block. Tighten the bolts to specification.
    18.  
    19. Install the rear end plate on the engine.
    20.  
    21. Install either the driveplate (automatic) or the flywheel (manual), observing the matchmarks made during removal.
    22.  
    23. If equipped with a manual transaxle, reinstall the clutch disc and pressure plate.
    24.  
    25. Install the oil pump.
    26.  
    27. Install the oil strainer and oil pan, using new gaskets.
    28.  
    29. Rotate the engine into its upright position and continue reassembly of the timing belt, idler pulley and covers.
    30.  
    31. Reinstall the engine in the car, following procedures outlined earlier in this section.
    32.  

    CLEANING AND INSPECTION



    See Figures 5, 6 and 7

    With the crankshaft removed from the engine, clean the crank, bearings and block areas thoroughly. Visually inspect each crankshaft section for any sign of wear or damage, paying close attention to the main bearing journals. ANY scoring or ridge on the crankshaft means the crankshaft must be replaced. Because of the crankshaft metallurgy, welding and/or regrinding the crankshaft is not recommended. The bearing faces of the crank may not be restored to their original condition which would cause the risk of premature bearing wear and possible failure.

    Using a micrometer, measure the diameter of each journal on the crankshaft and record the measurements. The acceptable specifications for both connecting rod and main journals are found in the Crankshaft and Connecting Rod specifications chart in this section. If ANY journal is beyond the acceptable range, the crank must be replaced.

    Additionally, each journal must be measured at both outer edges. When one measurement is subtracted from the other, the difference is the measurement of journal taper. Any taper beyond 0.0031 in. (0.08mm) is a sign of excess wear on the journal; the crankshaft must be replaced.



    Click image to see an enlarged view

    Fig. Fig. 5: A dial gauge may be used to check crankshaft end-play



    Click image to see an enlarged view

    Fig. Fig. 6: Carefully pry the shaft back and forth while reading the dial indicator



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    Fig. Fig. 7: A dial gauge may also be used to check crankshaft runout

    BEARING REPLACEMENT



    See Figures 8 and 9

    1. With the engine out of the car and inverted on a stand, remove the main bearing caps following the procedures given earlier in this section.
    2.  
    3. Once the bearing caps are removed, the lower bearing shell may be inspected. Check closely for scoring or abrasion of the bearing surface. If this lower bearing is worn or damaged, both the upper and lower half should be replaced.
    4.  

    Always replace bearing shells in complete pairs.

    1. If the lower bearing half is in good condition, the upper shell may also be considered usable.
    2.  
    3. The bearing shells, the crank throws and the flat surface of the engine block (on the oil pan face) are stamped with numbers (1 through 5) indicating the standard bearing size. This size is determined during the initial manufacturing and assembly process; replacement bearings must be of the same code (thickness) if the correct clearances are to be maintained. If the code on the bearing shell is unreadable, use the number on the block and/or the number on the crank throw to determine the bearing code. For 3E and 3E-E engines, refer to the selection chart to find the correct bearing for that position.
    4.  



    Click image to see an enlarged view

    Fig. Fig. 8: Main bearing identification on 3A and 3A-C engines



    Click image to see an enlarged view

    Fig. Fig. 9: Main bearing identification and selection chart on 3E and 3E-E engines

    1. Lift the crankshaft from the engine block and remove the upper bearing shells. Clean the area thoroughly (including the crankshaft journals) and allow the surfaces to air dry.
    2.  
    3. Install the upper bearing shells, then carefully place the crankshaft in position. Install the lower bearing shells into clean, dry caps. Do not oil the upper/lower bearing shells or the crankshaft journals at this time.
    4.  
    5. Place a piece of plastic gauging material (such as Plastigage® or similar) lengthwise (fore-and-aft) across the full width of each of the five crankshaft main bearing journals. Remember that the measuring material is dissolved by oil. Keep the crankshaft and bearings clean and dry.
    6.  
    7. Install the bearing caps with their bearing shells in their correct location and with the arrows pointing towards the front of the motor.
    8.  
    9. Install the bearing cap bolts and tighten them in three passes (and in the correct sequence, if applicable) to specification. Follow the procedures outlined in this section.
    10.  

    Do not rotate the crankshaft with the measuring plastic installed.

    1. Observing the correct removal sequence, gradually loosen and remove the bearing cap bolts. Carefully remove the bearing caps; the gauging material will be stuck to either the inside of the bearing shell or the face of the crankshaft.
    2.  
    3. Using the scale provided with the package of the gauging material, measure the material at its widest point. This measurement represents the main bearing oil clearance and should be checked against the Crankshaft and Connecting Rod Specifications chart in this section.
    4.  
    5. Remove every piece of the plastic gauging material from the crank and bearing caps. Remove the crankshaft, then coat the journals and bearings with clean motor oil.
    6.  
    7. Install the main bearing caps and the lower thrust washers. Make sure the arrows on the caps point towards the front (pulley end) of the motor.
    8.  
    9. Tighten the cap bolts in three passes (and in the correct sequence, if applicable) to specification. Follow the procedures outlined in this section.
    10.  
    11. Double check the end-play of the crankshaft. Turn the crankshaft through one or two full clockwise rotations, making sure that it turns smoothly and evenly with no binding.
    12.  

     
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