Chevrolet Scored or Burned Bearings
( This article is only about Chevrolet Antique Models )
Scored or Burned Bearings
When a bearing has scored or burned, either from lack of lubrication or from having been set up too tight, and not properly “worked in,” refitting the bearing is the only remedy.
A scored bearing is one whose surface has been slightly roughened, but where the babbitt metal has not been burned and run. A bearing of this kind can be refitted.
A burned bearing is one whose surface is badly roughened and where the babbitt has melted and started to run. This bearing cannot be used and a new one should be fitted.
Do not remove the babbitt bearings from the bearing caps unless it is necessary to replace them. Should this be necessary, be sure to see that the new bearing is firmly pressed into the cap and rests snugly against the bottom.
CAUTION: The best results can be obtained in the use of Prussian Blue by spreading a very thin coat on the finger tip then applying to the bearing of the crank shaft sufficient to give it only a pale blue tint.Prussian Blue spread quickly and if too much is used, more of the bearing face will show a” bearing” than is actually touching.
Place the bearing in the jaws of a vise. The upper crank shaft bearings should not be removed as they can be scraped in their proper positions.
Hold a bearing scraper firmly with both hands.With the cutting edge of the tool scrape off a little metal under each spot left by the Prussian Blue Care should be exercised in scraping bearings, as too much of the soft babbitt metal may be easily taken off. Scrape very lightly, and test the surface often. Before testing wipe out the pieces of metal from the bearing.
The object is to have the surface of the bearings and shaft touch at all points evenly.
The use of Prussian Blue shows the spots where the shaft touches, and by removing these “high spots” the bearing is finally worked down so that the shaft touches evenly at all points.
indicates a bearing that is properly fitted and shows one that is improperly fitted.
Chevrolet Scored or Burned Bearings Article Source – This article courtesy should goes to : Chevrolet Repair Guide of 1923 by Chevrolet Motor Company.