Originally Posted by focusv8

The bit that's broken serves no purpose other than for locking the cam in place when setting the cam position.
It's NOT to be used when loosening / tightening the Crankshaft bolt.

Originally Posted by GVK.

As above - There's a special tool that locks into the pullies to slacken the pulley bolts.

Bit late now. https://www.ebay.co.uk/itm/FORD-ROTU...-/111989188349

cheaper version https://www.ebay.co.uk/itm/LASER-TOO...gAAOSwX~dWomAl