[Richard]

I can't see how the sensor is attached to the engine, but I can feel around. There is a right angle gear box of some sort that is bolted to the front of the engine. There is a zerk fitting on the side of the gearbox but the fitting is blocked by a shaft on the water pump. The sensor tang fits securely in the gearbox and there are no signs of broken parts, wear, or scoring on the drive key.

I had Clarke bump the engine and the tang is NOT turning