How to stop flywheel from spinning without special tools?

Question

How do I stop the flywheel from spinning while torquing the bolts?

My repair manual says I should buy a special tool to do it, but I don't want to buy an expensive tool that I'll rarely use. Is there a way to do this without any special tools?

Answer 1

The Internet wasn't helping me much on this one, so I came up with a trick:

1. Put one of your pressure plate bolts into the flywheel (so the head is flush with the flywheel, but it doesn't need to be tight)
2. Place a pry bar, pipe, or some other piece of metal between the bolt head and the ground.
3. Turn the flywheel in the direction of engine rotation until it makes contact with your prop, and torque away!

(Closeup -- shown at an angle due to poor photography, but the bar is vertical)

Notes

1. It shouldn't hurt anything, but try not to scratch the edge of your flywheel with your prop (I wasn't terribly careful and I did not scratch my flywheel while doing this).
2. My pressure plate bolt did not have any damage (no bending, rounding, or excessive scratching) after torquing my flywheel bolts to ~80 ft-lbs. I successfully used it to install the pressure plate afterwards.
3. I was able to do this easily without having my prop fall over (I'm not especially skilled and I'm not usually that lucky!).
4. I like this solution because it isn't rough on the teeth of the flywheel and won't loosen the nut on the other end of the crankshaft.
5. There are some indentations around the edge of the flywheel that might work, but I prefer the nut solution because it allows you to keep the prop more vertical, which reduces risk of scratching the flywheel surface from having your prop slip.
6. Do not use the little posts that your pressure plate sits on -- those might work, but it's probably a Very Bad Idea that might affect your pressure plate installation and require you to buy a new flywheel (I'm glad I thought of the nut first and didn't attempt this out of desperation!).

Answer 2

Another user deleted an answer that is worth mentioning:

If you put a breaker bar on the nut at the opposite end of the crankshaft, it should be able to stop the shaft from turning when you torque your flywheel bolts.

Notes

A possible concern with this approach is that it might cause that nut to turn, as in this video https://www.youtube.com/watch?v=zDNzHELneWA, but it can certainly be done successfully.

Answer 3

I can't take credit for this but another option is to engage something with the teeth lining the flywheel. Using something like a board of wood would prevent scratching or gouging of the flywheel or other surfaces but other materials/tools could be used. Take this material and set one end against the teeth and one against the chassis or the ground. All you have to do now is spin some wrenches.

P.S. Credit goes to ChrisFix

Answer 4

Better use disc brake system on the flywheel. It gives effective results. But it has a disadvantage. I. e) wearing on the flywheel disc due to friction