^ really? that extreme? ive never heard of that, imma spend some time on youtube to see this. i figured that the trans bell housing would just get demolished...

 

I'd hate to see what 28 pounds of flying disc with teeth could do at 3 thousand rpm.
Maybe extreme,but It is something that you just don't want to test out in "practical mode" instead of theory!

 

Unless it actually broke into pieces, there's no way the flywheel could actually come out. The eshaft and the trans input shaft would hold it from moving more than a couple inches in any direction. It could sure make a lot of noise though.

 

The problem with forums is you get all kinds of advice, both qualified and not so much. Even experienced people sometimes take shortcuts and recommend them to others. They may know they're safe, but this advice is sometimes dangerous when others apply it. You have to decide if you want to do things right, or not so much and take the risk, even if it's minimal.

The torque range for the flywheel nut is 289-362 ft-lb, so the number to aim for is around 325 ft-lb.

I don't care if it's your first or 500th rebuild. Use a torque wrench or long pipe with a luggage scale. For example, if you put the pipe on and mark the pipe at 5ft from the center of the nut, you pull on the luggage scale till it reads 65lb.

As a bare minimum, you should use the 'stand on the end of the pipe' method, but divide 325 by weight of the person and make sure they stand on one foot at the right distance from center of nut. It may look funny, but it'll tighten the nut the right amount. Obviously, this won't work with the engine in car, lol. And even having enough room for the torque wrench or pipe is sometimes tough if the car is just on jacks.

(Aside: You can secure the flywheel from turning, with bolts on the engine to tranny holes and chain against the flywheel teeth. And always secure the car safely on jackstands, since the force you'll be applying could pull the vehicle off less safe support methods.)

Is a little bit of work and time too much for peace of mind on a fastener you may not touch for years, if ever? The engineers give you a torque spec., tell you to apply sealant on the flywheel nut to flywheel contact surface, and thread sealant on the threads. Are the few minutes spent not worth knowing you did it properly? If you're not experienced to know better or be certain, go with the safest option.

And about impact guns...even if yours is rated for 98798798 ft-lb, how do you really know you're in the range? Too many variables, including air pressure, time on the trigger, gun condition, etc. You don't want to overtighten either, which places more stress on the threads than needed.

This is why FC owner's have a bad rep. Too many doing things the quick way, and driving their cars for way too long with known problems and trying to save a few bucks and ending up wasting hundreds.

I don't mean any offense (although some people need to get off their high horse), just want to balance the thread so that those less experienced will opt for the safer option.

Lastly, if I got to an engine with chisel marks on the nut and knew it was a shop, I'd make sure anyone considering them would not go there and search results would bring up my story of half assed shoddy work, and let the forum know about them.