You need to buy or make a counter holding bar, so you can hold the crankshaft in place while you tighten the bolt.

You can make one like this , cost me less than $3. You could also go to a wrecking yard pull the A/C pulley and weld a bar to it, having a shop weld them together should be rather cheap, less than the $75 the bar costs through a parts store(if you can find them) You then bolt the bar to the crankshaft pulley, set the end of the bar against the frame and tighten the crankshaft bolt.


Yes, the engine vibration could cause it to back out and fall off.