Pulling the flywheel

Fish Whisperer · Jul 22, 2008

Hi guys, I am restoring a 1964 Evinrude 5.5hp Fisherman. I was not able to locate the special service tool to properly pull my flywheel, so I have picked up a harmonic balancer puller from an auto parts store. Everything seems to be okay except I am putting alot of force on this puller and it does not seem to be budging the flywheel. I was hoping you guys could tell me if that is normal or am I at risk of damaging something. Thanks in advance.

tashasdaddy · Jul 22, 2008

Re: Pulling the flywheel

are you using #8 hardened bolt, i the flywheel holes. if not get them. regular bolt will strip off. tighten it down. give the center tightening bolt a couple of good whacks with a hammer. then tighten some more. it is a compressed fit. it will finally go POP and come off, also did you leave the nut loose at the top of the shaft so you do not damage the shaft.

BillP · Jul 22, 2008

Re: Pulling the flywheel

On the really stuck ones I've found the alignment and torque value of the bolts make a big difference. Get them as perpendicular as possible and use a torque wrench to equal their pull against the center bolt. Then crank the center bolt a little at a time...I do 1/4 turn and tap the bolt lightly a few times. Sometimes they pop and others they release quietly. If that doesn't work use heat on the flywheel. In cases where nothing else works I heat the flywheel and put one of those frozen cooler dealies on the crank end to cool it. That method does wonders to free stuck parts.

One word of caution. A couple months ago I helped a friend take a flywheel off small diesel generator located on a remote island in the Bahamas where we didn't have electricity, heat guns, etc. It was stuck hard and we cranked the center bolt hard...it broke the flywheel into 3 pieces.

bp

tashasdaddy · Jul 22, 2008

Re: Pulling the flywheel

the flywheel can warp from heating.

ftltony · Jul 22, 2008

Re: Pulling the flywheel

Tash is right on the money here. You have to get that tool ALL tightened up and then beat that tool with a good rap of a hammer and that sucker will pop right off.

This is also one of those cases where it is EXTREMELY beneficial to put "anti sieze" on the shaft in case you have to repeat what you are doing in the future!

Xcusme · Jul 22, 2008

Re: Pulling the flywheel

I beg to differ.....use No oil, grease, anti-seize , no nothing on the crank shaft taper, it's a dry fit. Torque nut to factory specs to prevent shearing the flywheel key.

eavega · Jul 22, 2008

Re: Pulling the flywheel

I just managed to pop my first flywheel off last week, so obviously I have tons of experience

. What worked for me was the tighten the tool a 1/4 turn, then tap a bit with a hammer, then tighten some more. Definitely go with the grade 8 bolts. I did a second flywheel on a parts motor I am stripping down, and I didn't have the right size bolts for that particular flywheel, so I used grade 5 bolts. I did manage to get the flywheel off, but I could see where the bolts had started to flex.

Now, I read you don't need to be tapping too hard with the hammer, else you risk damaging the seals on the shaft. I don't know the truth of that, but I would proceed cautiously, just in case.

Good luck

-Eric

BillP · Jul 22, 2008

Re: Pulling the flywheel

I don't do hard raps anymore and can assure you I had a 4hp omc that got stuck past beating with a series of "hard" raps and tightening the center bolt. What I have experienced is cranking down the center bolt too hard and rapping hard has broken a flywheel. If my friend took pics I will post one to show it. Otherwise, heating has worked when nothing else has. If the flywheel is stuck hard and you have to get it off what else can you do? Heat to the point of very hot to keep your hands on. It's plenty to do the job and doesn't warp. If you want to be ultra conservative, run the engine hard, feel the flywheel and heat to that temp. Any heat is better than no heat and will help way more than ambient temp or beating the motor to death.

You guys seem to be confusing heating to expand with torching to cut.

bp

boatmonkey82 · Jul 22, 2008

Re: Pulling the flywheel

i have great luck in letting the puller sit on there with it being tight of course and by the time you lean back to open a beer it will pop off - scare the #@$$ out of you and fall in 10 ft of water , ok i have only done that once but if you let them sit for a bit they will pop , the hammer works too but the magnets dont like you for it , heat never hurt any of my wheels but if you get it too hot you run the risk of getting the upper seal and warping the wheel

BillP · Jul 22, 2008

Re: Pulling the flywheel

Xcusme said:
I beg to differ.....use No oil, grease, anti-seize , no nothing on the crank shaft taper, it's a dry fit. Torque nut to factory specs to prevent shearing the flywheel key.

That be very true. Mfgs installation specs that come in the box with many commercial application motors and pumps with tapered shafts say do NOT lube the taper or key. It's an engineering thing.

bp

wilde1j · Jul 22, 2008

Re: Pulling the flywheel

Get carried away with the heat and the magnets are magnets no more. Never needed more than the puller and a few whacks on the puller bolt and up it comes.

BillP · Jul 22, 2008

Re: Pulling the flywheel

wilde1j said:
Get carried away with the heat and the magnets are magnets no more. Never needed more than the puller and a few whacks on the puller bolt and up it comes.

...But they regain it back when cooled back down so you don't really hurt magnets by heating a flywheel.

bp

wilde1j · Jul 22, 2008

Re: Pulling the flywheel

Absolutely not so ... try magnetizing a piece of steel and heating it. It's gone forever! The magnetism is permanently gone unless you apply a strong, properly aligned aligned EMF.

Fish Whisperer · Jul 22, 2008

Re: Pulling the flywheel

Thanks to all for the input, I knew I had come to the right place. By the way wild1j, I do have an OEM servie manual for this project, they left out the "whack with a hammer part". I will give it a go tonight and post back with results. Thanks again, you guys are great.

HighTrim · Jul 22, 2008

Re: Pulling the flywheel

I agree with Jim and Tash, stay away from the heat. It is not needed, and can damage the flywheel. Stay away from pulling on the outer edges of the flywheel as well. As stated, I have found that patience pays off, letting it sit a while, along with light raps of the hammer. Grade 8 bolts are a must! Only screw them in 7/16 of an inch, no more, no less.

Also as important is to retorque it to specs after install and ensure that the taper is clean and dry as stated. No oils or antiseize or the like.

CATransplant · Jul 22, 2008

Re: Pulling the flywheel

No heat! If you're using the Grade 8 bolts, crank down good on the puller center bolt. If it doesn't pop, crank down on it some more, then go in the house and sleep on it. Usually, it will pop off while you're napping. If not, crank down a little more and repeat.

I don't like banging on puller center bolts. It can't do crankshaft bearings and thrust bearings any good. That flywheel will come off.

Sea18Horse · Jul 22, 2008

Re: Pulling the flywheel

CATransplant wrote;

I don't like banging on puller center bolts. It can't do crankshaft bearings and thrust bearings any good. That flywheel will come off.

I was thinking the same thing. I know that Tashasdaddy, Wilde1J et-al have forgotten more about fixing outboards than I will ever know. But personally I'm not comfortable rapping on a puller like that. When I do I always like to lift up on the flywheel so that it's against the upper side of the thrust bearing before tapping. If you don't any force you apply with the hammer is being absorbed by the thrust bearing. Hard to imagine that being good, plus it leaves less to loosen the flywheel.

Cheers................Todd

samo_ott · Jul 22, 2008

Re: Pulling the flywheel

I don't beat on em either. I just keep cranking the center bolt. It'll pop. And to stop if from dropping into 10' of water (!) just loosen the center bolt a few threads then it will stay on when it pops. It also saves it from crashing to the garage floor and busting things if inside. (no, no experience there!)

Now on the other hand, playing the devils advocate here, why bother with grade 8 bolts over grade 5 bolts when they are being screwed into aluminum? Any grade of steel should be stronger than the aluminums so why bother?

CATransplant · Jul 23, 2008

Re: Pulling the flywheel

samo_ott said:
I don't beat on em either. I just keep cranking the center bolt. It'll pop. And to stop if from dropping into 10' of water (!) just loosen the center bolt a few threads then it will stay on when it pops. It also saves it from crashing to the garage floor and busting things if inside. (no, no experience there!)

Now on the other hand, playing the devils advocate here, why bother with grade 8 bolts over grade 5 bolts when they are being screwed into aluminum? Any grade of steel should be stronger than the aluminums so why bother?

Experience. Grade 5 bolts get their threads stripped off. Grade 8 bolts don't.

iwombat · Jul 23, 2008

Re: Pulling the flywheel

i've just taken to using an impact wrench to tighten up the puller. It rattles everything around enough that i've never had to do anything else.

Pulling the flywheel

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