Stupid Flywheel Nut!

[rothfm]

GM280...Yes, scary when it popped at 3am! While I knew what it was, Wife gave me a rashon of crap needlesss to say :-(

 

[fmjnax]

Boy, what a chore! I got home with an electric impact wrench rated for 280 pounds of torque, a 1-5/16 impact socket, and a set of 5/16-24 grade 8 bolts and washers. The impact gun had the nut off in a matter of seconds. The actual pulling is proving to be a harder task.

I left the nut threaded on a bit (as I have read). got the puller in position, ensured even pressure, and started to crank on it. I've been cranking on it for an hour, tapping the pull bolt every few cranks. About 20 minutes ago it wouldn't turn anymore at all, so I hit it with the impact wrench (don't know if that was wise or not). I got it to turn down a little more, but now no amount of hammer and impact wrench will turn it. Pulling on my 36" breaker bar is fruitless. The grade 8 washers are even starting to bend!

I hit it with some more PB Blaster and I'll leave it sit under tension. I'll check it every so often and see if it has given way any. I've only been spraying the top, underneath the big nut. Can I spray anywhere up underneath it? Any other tricks or crucial things I may be missing?

 

[racerone]

Magic spray will not help.-------At 100 ft-lbs the flywheel taper has been stretched over the crank taper and is now locked.-------That is what drives the flywheel all day long at 5500 rpm with out damage.--------Give the centre bolt on the puller a rap or two with a hefty hammer.------That is how they come off easily.

 

[fmjnax]

Like maybe a 5lb hammer? Are we talking a hefty (but accurate) hit like I am pissed off at it or gentle but continuous hits?

 

[fmjnax]

Guess I asked prematurely. Grabbed the 5 poinder and whacked the puller bolt like I meant it. 3 hits and the flywheel popped up. Thanks guys for all the help. I would be lost without iBoats!

 

[gm280]

A little heat never hurts. If you have some type heat shrink heat gun try that. The flywheel is a bugger for sure. We've all been there and done that and it is really an experience to work through. I thought somebody shot me when mine let loose. So just be prepared for that crack as it finally lets go. It will happen after some working and hammering and heat and everything you can throw at it... And that IS the reason you have to make sure the taper shaft and flywheel surfaces are absolutely clean when you reinstall them back. And the have to be torqued to the proper torque setting too...

 

[gunfighter]

From an old helo mech here, a little heat will work wonders, if you have a heat gun that works, I have used the benzomatic, but do not really recommend using the flame. If you do use a torch you should replace the bolt
:lalala:

 

[racerone]

With heat there is too much risk of damage to the magnets on the hub.