Heating Mandrel

The heating mandrel is lathe turned brass.

It is inserted in the inner race of the main crankshaft bearing, and heated in situ with a blowlamp (to approx 80^oC). Taking care not to damage the bearing seals.

The heat is conducted to the inner race causing it to expand.
Tap the mandrel out and the expanded inner race will allow the crank to be inserted.

You have to be quick as the inner race begins contracting as soon as the heat source is removed. If the crank does not go fully home, remove crankshaft, replace and reheat mandrel.

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