Honda Accord/Prelude 1984-1995 Repair Guide

Crankshaft and Main Bearings

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REMOVAL & INSTALLATION



1984-89 Accord and 1984-91 Prelude

See Figure 1

  1. Remove the engine from the vehicle and place it on a work stand.
  2.  
  3. Remove the crankshaft pulley attaching bolts and washer.
  4.  
  5. Remove the front cover and the air conditioning idler pulley assembly, if so equipped. Remove the cover assembly.
  6.  
  7. Remove the timing belt and sprockets.
  8.  
  9. Invert the engine on a work stand. Remove the flywheel and the rear seal cover. Remove the oil pan and gasket. Remove the oil pump inlet and the oil pump assembly.
  10.  
  11. Insure all bearing caps (main and connecting rod) are marked so they can be installed in their original positions.
  12.  
  13. Remove the main bearing caps (and bridge assembly, if equipped). Use a crisscross pattern making three passes to loosen the bolts.
  14.  
  15. Turn the crankshaft until the connecting rod from which the cap is to be removed is up. Remove the connecting rod cap. Push the connecting rod and piston assembly up in the cylinder. Repeat the procedure for the remaining connecting rod assemblies.
  16.  
  17. Carefully lift crankshaft out of the block so the upper thrust bearing surfaces are not damaged. If the bearings are to be reused, they should be identified to insure that they are installed in their original position.
  18.  



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Fig. Fig. 1: Handle the crankshaft carefully


WARNING
Handle the crankshaft with care to avoid damage, fracture or scratching of the finished surfaces.

To install:
  1. Inspect all the machined surfaces on the crankshaft for nicks, scratches or scores which could cause premature bearing wear. Inspect the bearing clearances.
  2.  
  3. If necessary for replacement, remove the main and connecting rod bearing inserts. Refer to the applicable bearing replacement procedures in this section.
  4.  
  5. Install a new rear oil seal in the seal cover.
  6.  
  7. Apply a thin coat of grease to the rear crankshaft surface. Do not apply sealer to the area forward of oil sealer groove.
  8.  
  9. Apply a light coat of assembly grease to the journals and bearings. Carefully lower the crankshaft into place.
  10.  
  11. Turn the crankshaft throw to the bottom of the stroke. Push the piston until the rod bearing seats on the crankshaft journal.
  12.  
  13. Install the connecting rod cap with the nuts finger-tight. Repeat this for the remaining pistons, then tighten them to the proper specification.
  14.  
  15. Install the main bearing caps (and bridge assembly, if equipped). Tighten the bolts to specification (refer to the torque specification chart in this section). Use a crisscross pattern making three passes to tighten the bolts.
  16.  
  17. Check the crankshaft end-play.
  18.  
  19. If the end-play exceeds specification, replace the thrust bearing. If the end-play is less than the specification, inspect the thrust bearing faces for damage, dirt or improper alignment. Install the thrust bearing and align the faces. Recheck the end-play.
  20.  
  21. After the piston and connecting rod assemblies have been installed, check the connecting rod side-play.
  22.  
  23. Install the remaining components in the reverse order of removal.
  24.  

1990-95 Accord and 1992-95 Prelude

See Figures 2, 3, 4, 5, 6, 7 and 8

Steps are given for crankshaft removal with the pistons in place in the block.

  1. With the engine removed from the car and the flywheel removed from the engine, unbolt the rear or right side cover from the engine.
  2.  
  3. Remove the balancer drive case.
  4.  



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Fig. Fig. 2: Remove the balancer drive case

  1. Insert a metal dowel or similar tool in the maintenance hole of the front balancer shaft to hold it in place. Unbolt the belt sprocket and remove it.
  2.  
  3. Remove the bolt from the maintenance hole for the rear balancer shaft. Align the bolt hole and the balancer shaft hole. Insert a 6x100mm dowel or bolt to engage and hold the shaft; remove the sprocket or drive gear.
  4.  



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Fig. Fig. 3: Hold the balancer shaft with a bolt or similar tool through the maintenance hole

  1. Remove the oil screen and the oil pump. Remove the baffle plate.
  2.  
  3. Remove the bolts securing the bearing caps (and bridge, if equipped), then remove the bearing caps. Release the tension by turning each bolt about 1 / 3 of a turn at a time, beginning at one corner, then moving to the diagonally opposite corner. On all except Accord V-6, follow the sequence shown in the illustration.
  4.  



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Fig. Fig. 4: Loosening sequence for the bearing caps and bridge

  1. Turn the crankshaft so that the No. 2 and 3 crankpins are at the bottom. Remove the rod caps and bearings, keeping them in order.
  2.  
  3. Lift the crankshaft out of the engine, being careful not to damage the journals.
  4.  
  5. Remove the bolts securing the retainer, then remove the front and rear balancer shafts.
  6.  

To install:
  1. Insert the bearing halves into the block and piston rods.
  2.  
  3. Hold the crankshaft so that the journals for pistons No. 2 and 3 are straight down; lower the crankshaft into the block. Make certain the crank journals seat into piston rods 2 and 3.
  4.  
  5. Install the rod caps and nuts finger-tight.
  6.  
  7. Rotate the crankshaft clockwise and seat the journals into connecting rods 1 and 4. Install the rod caps and nuts finger-tight.
  8.  
  9. Check the rod bearing clearance using Plastigage® or similar compressible measuring media.
  10.  
  11. Coat the thrust washer and bolt threads with a light coat of clean oil. Install the thrust washers, main bearing caps and bearing cap bridge. Check the bearing clearance using Plastigage® or similar compressible measuring media.
  12.  
  13. Tighten the bolts in two passes: On the first pass, in the correct sequence, bring each bolt to approximately 22 ft. lbs. (30 Nm). On the second pass, in the correct sequence, bring each bolt to its final torque of 52 ft. lbs. (72 Nm).
  14.  
  15. Insert the balancer shafts into the block, then install the thrust metal to the front balancer shaft and block. Tighten the retaining bolt to 9 ft. lbs. (12 Nm).
  16.  



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Fig. Fig. 5: Installation of the balancer shafts and thrust metal



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Fig. Fig. 6: Tightening sequence for all except Accord V-6



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Fig. Fig. 7: Tightening sequence for the Accord V-6

  1. Make certain the mating surfaces of the right side cover and the block are absolutely clean and dry. Apply a liquid gasket sealant to the contact face of the cover, then install it on the block. Tighten the retaining bolts to 9 ft. lbs. (12 Nm).
  2.  
  3. Make certain the mating surfaces of the oil pump and engine block are absolutely clean and dry. Apply a liquid gasket sealant to the contact surface of the oil pump. Apply grease to the lips of the oil pump seal and the balancer seal. Install the oil pump and tighten the bolts to 9 ft. lbs. (12 Nm). Wipe the excess grease from the crank and balancer shafts; check that the oil seals did not distort during installation.
  4.  
  5. Install the baffle plate, then install the oil screen.
  6.  
  7. Apply molybdenum disulfide grease to the thrust surfaces of the balance gears before installation of the driven gear and the drive gear case.
  8.  



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Fig. Fig. 8: Apply moly grease to the thrust faces before installing the drive gear case

  1. Use the 6x100mm tool to hold the rear balancer shaft in place. Install the balancer pulley and gear. Tighten the bolt to 18 ft. lbs. (25 Nm).
  2.  
  3. Pin the front balancer shaft in place and install its pulley; tighten the bolt to 22 ft. lbs. (30 Nm).
  4.  
  5. On the balancer gear case, align the groove on the pulley edge to the pointer on the gear case.
  6.  
  7. Hold the rear balancer shaft in place and install the gear case. Tighten the nut and bolts to 18 ft. lbs. (25 Nm).
  8.  

CLEANING AND INSPECTION



See Figure 9

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.



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Fig. Fig. 9: Check the journals for out-of-round and taper

BEARING REPLACEMENT



  1. With the engine out of the car and inverted on a stand, remove the main bearing caps following the procedures given 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 usually 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 a code 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 code on the block and/or the crank throw to determine the bearing size. A well equipped machine shop or parts outlet should be able to help you find the correct bearing size for that position.
  4.  
  5. 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.
  6.  
  7. 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.
  8.  
  9. Place a piece of plastic gauging material (such as Plastigage® or similar) lengthwise (fore-and-aft) across the full width of each of the crankshaft main bearing journals. Remember that the measuring material is dissolved by oil. Keep the crankshaft and bearings clean and dry.
  10.  
  11. Install the bearing caps with their bearing shells in their correct location.
  12.  
  13. Install the bearing cap bolts (and bridge assembly, if equipped) and tighten them using the correct sequence to the proper specification. Follow the procedures outlined in this section.
  14.  

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 (and bridge assembly, if equipped). 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. If the bearing insert and journal appear intact, and are within tolerances, no further main bearing service is required. If it is out of specification, determine if the journals are worn. If so, replace the crank. If the journals are within specification, replace the bearings.
  8.  
  9. Assemble the engine using the procedures in this section.
  10.  

CRANKSHAFT END-PLAY/CONNECTING ROD SIDE-PLAY



See Figure 10

Place a small pry bar between a main bearing cap and crankshaft casting, taking care not to damage any journals. Pry backward and forward; measure the distance between the thrust bearing and crankshaft with a feeler gauge or dial indicator. Compare the reading with specifications. If too great a clearance is determined, a main bearing with a larger thrust surface or crank replacement may be required. Check with an automotive machine shop for their advice.



Click image to see an enlarged view

Fig. Fig. 10: A dial indicator can be used to check crankshaft end-play

Connecting rod clearance between the rod and crankthrow casting can be checked with a feeler gauge. Pry the rod carefully on one side as far as possible and measure the distance on the other side of the rod. Compare the reading with specifications.

 
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