Advice for cutting a flywheel off

[jerry-ahrens]

Wow, sounds like you have a stubborn one! I’m surprised that you didn’t pull the threads out of the flywheel before breaking off one of the three puller bolts. Especially since they are 1/4 inch. I’ve had that happen to me before, and on one occasion, I ended up drilling and installing 3/8 Helicoil inserts so I’d have a stronger thread to pull on. Actually, the Helicoil insert is much stronger than the original aluminum threads that you have now. This may be a better option than ruining the crankshaft. Just my opinion,I may be wrong.

[wetwillie]

I attribute my luck in removing the broken bolt to the liberal coating of Anti-sieze that I lubed it with before threading it in.
For once, a little forethought paid off.
Btw, Hey Chinewalker, were you a member of the Classic Glastron forum at one time? I seem to remember there being a member with the same name quite some time ago.

[auldscott]

Echoing David Bartlett’s comment: the key to striking the end of the crankshaft to shock the flywheel loose is to apply a sharp, hard, fast hit – I use a light ball pein hammer. A sledge or a lead hammer will deliver a heavy blow, but it will not be a sharp shock. If you have not done it already, swing the hammer as fast as you can, but don’t take a full "take that!" swing, just a sharp snap of the hammer head.

I have not experimented with using an air chisel with a blunt tool. My guess is that it will not deliver enough force to work.

If you decide to cut it off, work with great care. I’d use a Dremel with a 1" reinforced cutoff wheel. First cut away the flywheel near the center. When you get near the shaft, work ever more slowly. I don’t know whether a few shallow grooves cut into in the shaft will weaken it, but there is a lot of stress there. (I have not done this, but I have cut some major steel with a Dremel. It just takes a while.)

[Chris]

quote david bartlett:

I would not use a "Lead" hammer as you mentioned above. I would go for something heavy and solid.

Exactly what I was about to type reading above. You want the harsh "shock" of an impact, you don’t want to soften the blow.

I think so many of us have been in this position. Not fun, but tension on the puller and a good amount of hard pinging usually will do it.

[outbdnut2]

Some years ago before I knew any better, I used a brake drum puller on a stubborn Big Twin flywheel that wouldn’t come off with a cheapie bolt puller – I learned my lesson – the flywheel cracked.
Dave

[wetwillie]

I’ve been too busy to mess with it since my last post. However, a good friend dropped by, looked at my predicament and suggested that I hit it from the side while its under tension. Said he had some luck removing a stuck one himself that way. I’m planning on taking his advice when I get back to it. In the meantime, it remains under tension with a thick film of Kroil on it.

[wetwillie]

Well, I thought it only right that I post another update. This will be my last on this topic. I snapped another OMC puller bolt off yesterday. This came after I tried heating the area with a torch and whacking it several times with a steel hammer while under tension with the puller. This is my last post on the topic because I decided to list the motor As Is on CL last night. I got a call this morning from a friend who wants to buy it. That will be The End of this ordeal. Thanks to everyone that responded to my initial post.

[1936johnson]

David Bartlett is exactly right. Tighten the puller down as tight as it will go without breaking something and then whack the center puller bolt with a 2lb STEEL hammer. That SOB will pop right off. The lead hammer does not produce the needed SHARP blow.
Steve Stevens

[Author]

Posts