Making Bearing Shims

bearing shim

Main bearing shim for a 6 HP IHC Model M.

Drawing by John M. Edgerton

Content Tools

I don't know if this tool is worth writing about but it sure worked for me!

I'm sure other restorers have had to make bearing shims one time or another. Cutting the outline of the shim is no problem, but how do you make the hole through the thin shim stock? I don't have any punches that will work on metal, so I came up with this idea.

I took two pieces of steel bar 5- by 1-1/2- by 1/4-inch thick, clamped them together and bored two 17/64 inch holes 2 inches apart and about 3/8 inch in from one edge. These two holes may vary with the shape of the shims you're making.

In the middle of the 5 inches (at 2-1/2 inches) I bored a 21/32 inch hole, which is the size of my bearing bolt, through both pieces. By drawing a circle where I want the hole bored in the new shim, I can now line the hole up with the 21/32 inch hole, clamp the two pieces together using two 1/4 inch bolts in the 17/64 inch holes. Put this in your drill vise and use the 21/32 inch drill to  drill a hole in your shim. Of course not everyone has the same size bearing bolts, so the 21/32 inch will vary. My bolts are 5/8 inch, but I like to drill the shims a little bit larger.