Flatten bolt holes 1

Easy Way to flatten distorted bolt holes in oil pan, etc

The bolt holes on timing chain covers and oil pans are made from very thin steel and will distort if a PO tightened the bolts too tight.

Here is how I flatten any distorted bolt holes in an oil pan, timing chain cover, and other “tin” on the engine.

I use a piece of round steel with fairly flat ends approximately the size of the round washer on the piece. For instance, the piece shown here is 5/8″ diameter and it works well on MGB timing chain covers.

First picture: Place the round steel in a vice so that it sticks up more than the piece you are working on is deep.

Flatten bolt holes 1

Second picture: Place the piece you are working on upside down over the round steel. The steel now acts as an anvil.

Flatten bolt holes 2

Third picture: Use a lightweight (8 0z) ball peen hammer and tap tap tap until the distortion is flattened. No heavy hitting.

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Check the results with a straightedge.

1 thought on “Easy Way to flatten distorted bolt holes in oil pan, etc

  • Amsoil Dealer #352885 Al Dawes December 27, 2023 at 8:47 am

    Great Tip for correcting DPO heavy handed tightening by not understanding “Size Matters” when it comes to torquing of bolts.
    Thank You for sharing this “Fox Trick”!

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