Trying to remove flywheel. Need help!

[sr522re]

So I removed the center nut and put a harmonic balancer puller on using 3 1/4-20 bolts as required. Started cranking on the center bolt and I can't get the flywheel to budge. I even tried using an impact and actually busted one of the 1/4-20 bolts in the threaded holes. Assuming I can drill it out, what am I doing wrong? Need some help and appreciate any input.

Thanks,

Chris

 

[hardwater fisherman]

First you should leave the crankshaft nut on but not tight. This is to stop it from flying off when it lets go. Are you using grade 8 bolts? Also you can give the center bolt on the puller a solid rap with a hammer to break it free.

 

[James R]

You need to use high tensile bolts in that application. A 1/2 inch air impact gun is the way to go. If the fly wheel does not pop off, leave the puller under tension and strike the end of the puller center bolt with a hammer. Be judicious about the application of the hammer. I had one recently that would not move. An in the business friend used his air impact gun on 200PSI.and his special OMC puller and bolts to do the job.

 

[gm280]

Absolutely use grade eight bolt. Otherwise, you will just keep snapping them off. Install the grade eight bolts at least 1/2" or a little more deep. But not much deeper or you can go through and damage the ignition parts underneath. Loosen up the center nut but leave it on a couple threads. Then using a breaker bar or impact wrench, tighten the center bolt at tight as you can. If that doesn't pop it loose, whack that center bolt with a good heavy hammer. If that doesn't remove it, leave it and come back later and tighten the center bolt again and a few more whacks with the hammer. It takes time and when it does break loose, you will hear it and think it broke. But no, it is just the sound it makes when it lets loose. Good luck, but everybody has gone through those same or similar procedures with theirs. JMHO!

 

[sr522re]

Thank you guys! I extracted the broken bolt and now starting over again. This time with grade 8 bolts. Lol, what was I thinking??? Great advice and I will try the above mentioned procedure.

Thanks again!

 

[sr522re]

Flywheel removed! Just used the grade 8 bolts, some lubricant, an impact, and one good smack with a hammer and it loosened right up. Thanks so much for the assistance!

 

[gm280]

Flywheel removed! Just used the grade 8 bolts, some lubricant, an impact, and one good smack with a hammer and it loosened right up. Thanks so much for the assistance!

Good news. Now YOU too can offer others such experience when they post on here about removing their flywheel. It is a lot harder then it looks. And grade eight bolts are a must. It took me two tries with out grade eight bolts. I snapped other bolt so easily I couldn't believe it. But glad you succeed now. :thumb:

 

[F_R]

Consider the science behind what you are doing. The crankshaft (and flywheel) are able to move upward and downward a certain amount, depending on engine model. Gravity holds it in the downward extreme of its possible movement. Now, when you apply a hammer blow to the shaft in an effort to remove the flywheel, you are attempting to drive the shaft out of the flywheel. How do you expect it to be driven down and out when it is resting on whatever limits its downward movement? Ain't going to happen.. SO, the secret is to lift it up to the upper limit of its possible movement before striking it with a hammer to knock it down and out.

In other words---Tighten puller as much as possible without breaking something. Then if it doesn't pop off, LIFT or gently pry the flywheel upward enough to lift it off whatever supports it, then give the puller's center bolt a whack or two or three with a hammer. A big heavy hammer bash IS NOT required and actually may damage the shaft, or bearings. All you need is a 12 or 16oz (max) hammer and give it sharp blows, NOT heavy bashes!!!

 

[flyingscott]

Consider the science behind what you are doing. The crankshaft (and flywheel) are able to move upward and downward a certain amount, depending on engine model. Gravity holds it in the downward extreme of its possible movement. Now, when you apply a hammer blow to the shaft in an effort to remove the flywheel, you are attempting to drive the shaft out of the flywheel. How do you expect it to be driven down and out when it is resting on whatever limits its downward movement? Ain't going to happen.. SO, the secret is to lift it up to the upper limit of its possible movement before striking it with a hammer to knock it down and out.

In other words---Tighten puller as much as possible without breaking something. Then if it doesn't pop off, LIFT or gently pry the flywheel upward enough to lift it off whatever supports it, then give the puller's center bolt a whack or two or three with a hammer. A big heavy hammer bash IS NOT required and actually may damage the shaft, or bearings. All you need is a 12 or 16oz (max) hammer and give it sharp blows, NOT heavy bashes!!!

I disagree completely never pry on the flywheel never use anything to brace it up. The puller is pulling up on the flywheel and pushing down on the crank so force is neutral because they are attached to each other. The hammer blow provides a vibration that That allows them to release from each other. I have never had to hit the puller bolt with anything bigger than a 16 OZ carpenters hammer and have NEVER used an impact driver and never had one not come off. Never had to hit it harder than like driving a nail.

 

[HighTrim]

I agree with Frank. Always lift up on the flywheel before rapping it with a hammer, if needed. Too many bearings damaged from guys wailing away on the center bolt without lifting up on the flywheel. It is usually the bigger HP motors, with large crank, that have been sitting for many years that give the most trouble. Small hp motors should not give much resistance with a proper puller. I bought an actual OEM puller a while back, and it is well worth the money if you do this a lot.

I did a late 60s 40hp OMC once, that I had to put a 4 foot extension bar on the handle of the wrench for the center bolt to get it to pop!

I find 7/16" is a good measurement to thread your grade 8 bolts into the flywheel. Enough to grab, yet not too deep that it will damage anything.

 

[James R]

In spite of some conjecture amongst the gang I am pleased that you managed to pull it off. Not so difficult really.