Chevrolet Citation/Omega/Phoenix/Skylark 1980-1985 Repair Guide

Crankshaft

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REMOVAL & INSTALLATION



  1. Remove the engine assembly as previously outlined.
  2.  
  3. Remove the engine front cover.
  4.  
  5. Remove the timing chain and sprockets.
  6.  
  7. Remove the oil pan.
  8.  
  9. Remove the oil pump.
  10.  
  11. Stamp the cylinder number on the machined surfaces of the bolt bosses of the connecting rods and caps for identification when reinstalling. If the pistons are to be removed from the connecting rod, mark cylinder number on piston with a silver pencil or quick drying paint for proper cylinder identification and cap to rod location.
  12.  
  13. Remove the connecting rod caps and install thread protectors.
  14.  
  15. Mark the main bearing caps so that they can be reinstalled in their original positions.
  16.  
  17. Remove all the main bearing caps.
  18.  
  19. Note position of keyway in crankshaft so it can be installed in the same position.
  20.  
  21. Lift crankshaft out of block. Rods will pivot to the center of the engine when the crankshaft is removed.
  22.  
  23. Remove both halves of the rear main oil seal.
  24.  

To install:

  1. Measure the crankshaft journals with a micrometer to determine the correct size rod and main bearings to be used. Whenever a new or reconditioned crankshaft is installed, new connecting rod bearings and main bearings should be installed. See "Main Bearings" and "Rod Bearings".
  2.  
  3. Clean all oil passages in the block (and crankshaft if it is being reused).
  4.  

A new rear main seal should be installed anytime the crankshaft is removed or replaced.

  1. Install sufficient oil pan bolts in the block to align with the connecting rod bolts. Use rubber bands between the bolts to position the connecting rods as required. Connecting rod position can be adjusted by increasing the tension on the rubber bands with additional turns around the pan bolts or thread protectors.
  2.  
  3. Position the upper half of main bearings in the block and lubricate with engine oil.
  4.  
  5. Position crankshaft keyway in the same position as removed and lower into block. The connecting rods will follow the crank pins into the correct position as the crankshaft is lowered.
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  7. Lubricate the thrust flanges with 1050169 lubricant or equivalent. Install caps with lower half of bearings lubricated with engine oil. Lubricate cap bolts with engine oil and install, but do not tighten.
  8.  
  9. With a block of wood, bump shaft in each direction to align thrust flanges of main bearing. After bumping shaft in each direction, wedge the shaft to the front and hold it while torquing the thrust bearing cap bolts.
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In order to prevent the possibility of cylinder block and/or main bearing cap damage, the main bearing caps are to be tapped into their cylinder block cavity using a brass or leather mallet before attaching bolts are installed. Do not use attaching bolts to pull main bearing caps into their seats. Failure to observe this information may damage the cylinder block or a bearing cap.

  1. Tighten all main bearing caps to specification.
  2.  
  3. Remove the connecting rod bolt thread protectors and lubricate the connecting rod bearings with engine oil.
  4.  
  5. Install the connecting rod bearing caps in their original position. Tighten the nuts to specification.
  6.  
  7. Complete the installation by reversing the removal steps.
  8.  

CLEANING & INSPECTION





Click image to see an enlarged view

Fig. Fig. 1 A dial gauge may also be used to check crankshaft run-out



Click image to see an enlarged view

Fig. Fig. 2 Mounting a dial gauge to read crankshaft run-out



Click image to see an enlarged view

Fig. Fig. 3 Turn the crankshaft slowly by hand while checking the gauge

  1. Wash the crankshaft in a suitable solvent and dry completely using compressed air.
  2.  
  3. Measure the dimensions of the main bearing journals and crankpins with a micrometer for out-of-round, taper or undersize. Compare with the specifications charts found earlier in this section.
  4.  
  5. Check the crankshaft for run-out by supporting at the front and the rear main bearing journals in "V" blocks and check at the front and rear intermediate journals with a dial indicator.
  6.  
  7. Replace or recondition the crankshaft if it falls outside of specifications.
  8.  

 
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