Crankshaft

Cleaning

 CAUTION: Handle the crankshaft (6303) with care to avoid possible damage to the finished surfaces.

Clean the crankshaft with solvent, then blow out all oil passages with compressed air.

Measure the diameter of each journal in at least four places to determine an out-of-round, taper or undersize condition. For Specifications, refer to Section 03-01A (3.8L) or Section 03-01B (5.0L).

On an engine used with a manual transmission, check the fit of the pilot bearing (7600) in the bore of the crankshaft . A needle roller bearing and adapter assembly is used as a pilot bearing . It is press fit directly into the crankshaft and should not be loose. Inspect the inner surface of the pilot bearing for wear or a bell-mouth condition. Check the inside diameter of the pilot bearing to see if it is worn or damaged. The bearing and adapter cannot be serviced separately. The needle bearing pilot bearing can only be installed with the seal end of the pilot bearing facing the transmission. The pilot bearing and seal are pre-greased and does not require additional lubrication. A new pilot bearing must be installed whenever a pilot bearing is removed.

Inspect the pilot bearing , when used, for roughness, evidence of overheating or loss of lubricant. Replace pilot bearing if any of these conditions are found.

Journals, Refinishing

Dress minor imperfections such as scores, nicks or burrs with an oil stone. If the journals are severely marred or exceed the service limit, they should be refinished to size for the next undersize bearing.

If required, machine the journals to give the proper clearance with the next undersize bearing. If the journals will not clean up to maximum undersize bearing available, replace the crankshaft .

Always reproduce the same journal shoulder radius that existed originally. Too small a radius will result in fatigue failure of the crankshaft . Too large a radius will result in bearing failure due to radius ride of the bearing.

After refinishing the journals, chamfer the oil holes. Polish the journal with a No. 500 grit polishing cloth and engine oil (crocus cloth may also be used as a polishing agent) to obtain a smooth finish.