ZDX V6-3.7L (2010)
Crankshaft Main Bearing: Service and Repair
Crankshaft Main Bearing Replacement
Main Bearing Clearance Inspection
1. Remove the main bearing caps and the bearing halves See: Crankshaft/Service and Repair/Crankshaft and Piston Removal.
2. Clean each main journal and bearing half with a clean shop towel.
3. Place one strip of plastigage across each main journal.
NOTE: If the engine is still in the vehicle when you bolt the main cap down to check the clearance, the weight of the crankshaft and the drive plate will
flatten the plastigage further than just the torque on the cap bolt and give you an incorrect reading. For an accurate reading, support the crank with a jack
under the counterweights, and check only one bearing at a time.
4. Reinstall the bearings and the bearing caps, then torque the bearing cap bolts to 74 Nm (7.5 kg-m, 55 lb-ft), and the bearing cap side bolts to 49
Nm (5.0 kg-m, 36 lb-ft) in the proper sequence See: Crankshaft/Service and Repair/Crankshaft and Piston Installation.
NOTE:
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Apply new engine oil to the bolt threads and flanges.
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Do not rotate the crankshaft during inspection.
5. Remove the bearing cap and the bearing half, and measure the widest part of the plastigage.
Main Bearing-to-Journal Oil Clearance
6. If the plastigage measures too wide or too narrow, remove the crankshaft, and remove the upper half of the bearing. Install a new, complete
bearing with the same color code, and recheck the clearance. Do not file, shim, or scrape the bearings or the caps to adjust clearance.
7. If the plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (the color listed above or below that one), and check
clearance again. If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crankshaft and start
over See: Crankshaft/Service and Repair/Crankshaft and Piston Removal.
Main Bearing Selection
Block Bore Code Locations
Letters or bars have been stamped on the end of the engine block as a code for the size of each of the four main journal bores.
Use them, and the numbers or bars stamped on the crankshaft (codes for main journal size), to choose the correct bearings. If the codes are
indecipherable because of an accumulation of dirt and dust, do not scrub them with a wire brush or scraper. Clean them only with solvent or detergent.
