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H. L. Chauvin · 02-29-2016, 01:54 AM

FWIW: One (1) Proven Vintage Method for Adjusting Babbitt Bearings:

May not be your problem; however, heard a few times where some recommend slightly tight Babbitt bearings prior to rebuild.

Just in case anyone is interested, on page 99, paragraph 386, and Figure 237 in Ford's Model T Service Manual, Ford describes how to correctly adjust Babbitt bearings that are fed oil by the splash system, (like our Model A's), as opposed to the oil being fed through high psi oil pump pressure like that of modern cars today.

Ford's Model T method worked beautifully from 1909 until much later when Fords went to insert bearings.

So simple ..... so quick ....... thousands and thousands of steam engines mechanics worldwide were adjusting Babbitt bearings with this same method for two (2) generations even before Ford's first Model T hit the road.

In my rural area, years ago, we had at many, many vintage industrial mechanics adjusting Babbitt bearings with this vintage method for old steam engines still used in mills.

If a Babbitt bearing cannot easily slide sideways, it is usually too tight to maintain an unpressurized thin oil film between the Babbitt and the journals .... just that simple .... and oil is not just a lubricant for Babbitt ....... it is also a coolant ..... no oil in an unpressurized Babbitt bearing means heat generation for a very soft Babbitt material with a very low melting point.

I learned this same method as a teenager from local senior steam engine mechanics and never had a single Babbitt bearing failure.

Turn Model A engine upside down with no Babbitt bearings assembled.

One by one, wipe off excess oil from all crankshaft journals and Babbitt bearings.

Remove shims until no movement can be felt up and down for each individual bearing; but movement should easily occur sideways. After achieving such, rotate journal in Babbitt to check for concentricity and ease of operation. (Adjust connecting rods without pistons with rings in cylinders.)

After adjusting all individually, oil all journals and Babbitt and assemble with correct amount of shims.

Much later after Model A production, in the 1950's, Plastigage was introduced where some 1950's and later Model A owners began using Plastigage to adjust bearings; I much prefer the vintage method ................ each to his own method ..... whatever it may be.

Hope this helps as well as it has helped me and others.

02-29-2016, 01:54 AM	#10
H. L. Chauvin Senior Member Join Date: May 2010 Posts: 4,179	Re: Why did tbis rod fail? FWIW: One (1) Proven Vintage Method for Adjusting Babbitt Bearings: May not be your problem; however, heard a few times where some recommend slightly tight Babbitt bearings prior to rebuild. Just in case anyone is interested, on page 99, paragraph 386, and Figure 237 in Ford's Model T Service Manual, Ford describes how to correctly adjust Babbitt bearings that are fed oil by the splash system, (like our Model A's), as opposed to the oil being fed through high psi oil pump pressure like that of modern cars today. Ford's Model T method worked beautifully from 1909 until much later when Fords went to insert bearings. So simple ..... so quick ....... thousands and thousands of steam engines mechanics worldwide were adjusting Babbitt bearings with this same method for two (2) generations even before Ford's first Model T hit the road. In my rural area, years ago, we had at many, many vintage industrial mechanics adjusting Babbitt bearings with this vintage method for old steam engines still used in mills. If a Babbitt bearing cannot easily slide sideways, it is usually too tight to maintain an unpressurized thin oil film between the Babbitt and the journals .... just that simple .... and oil is not just a lubricant for Babbitt ....... it is also a coolant ..... no oil in an unpressurized Babbitt bearing means heat generation for a very soft Babbitt material with a very low melting point. I learned this same method as a teenager from local senior steam engine mechanics and never had a single Babbitt bearing failure. Turn Model A engine upside down with no Babbitt bearings assembled. One by one, wipe off excess oil from all crankshaft journals and Babbitt bearings. Remove shims until no movement can be felt up and down for each individual bearing; but movement should easily occur sideways. After achieving such, rotate journal in Babbitt to check for concentricity and ease of operation. (Adjust connecting rods without pistons with rings in cylinders.) After adjusting all individually, oil all journals and Babbitt and assemble with correct amount of shims. Much later after Model A production, in the 1950's, Plastigage was introduced where some 1950's and later Model A owners began using Plastigage to adjust bearings; I much prefer the vintage method ................ each to his own method ..... whatever it may be. Hope this helps as well as it has helped me and others.