Crankshaft Alternator Nut will not budge

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Story time.

I had a rotor nut that I tried to get off for a long time. My "supposed" 600 lb air impact gun wouldn't budge it, even with my compressor turned well above the guns max. A 24" breaker bar with a 4 foot fence post wouldn't budge it.

I was relating the story to a visitor who said he bet his Craftsman 450 lb impact gun would take it off. I laughed and said he was welcome to try. He got his gun, plugged it into the wall, hit the trigger and it was off instantly!

Clearly, I was putting more than 450 lb on with a breaker bar/fence post - more like 1000 lb but a 450 lb electric impact wrench made it easy. Don't know what to make of that to this day.

The nut and shaft were fine and there was no Locktite. It did have the tooth washer.
 
marshg246 said:
Story time.

I had a rotor nut that I tried to get off for a long time. My "supposed" 600 lb air impact gun wouldn't budge it, even with my compressor turned well above the guns max. A 24" breaker bar with a 4 foot fence post wouldn't budge it.

I was relating the story to a visitor who said he bet his Craftsman 450 lb impact gun would take it off. I laughed and said he was welcome to try. He got his gun, plugged it into the wall, hit the trigger and it was off instantly!

Clearly, I was putting more than 450 lb on with a breaker bar/fence post - more like 1000 lb but a 450 lb electric impact wrench made it easy. Don't know what to make of that to this day.

The nut and shaft were fine and there was no Locktite. It did have the tooth washer.
Click to expand...

Could have been the vibration from the specific RG....this has a surprisingly potent effect on stuck fixtures.
 
Last year I bought a used Harbor Freight electric impact gun for $20 at a local flea market.
I then used it on a Norton 500 crankcase timing side to get the cam nut and crankshaft oil pump gear off.
They had been stuck for the 30 years I've had it. Manual tools would not budge them.
Hardest part was to make some wood shims to block the chain gears from turning while using the impact.
Why did I wait so long to get that tool?
 
marshg246 said:
Story time.

I had a rotor nut that I tried to get off for a long time. My "supposed" 600 lb air impact gun wouldn't budge it, even with my compressor turned well above the guns max. A 24" breaker bar with a 4 foot fence post wouldn't budge it.

I was relating the story to a visitor who said he bet his Craftsman 450 lb impact gun would take it off. I laughed and said he was welcome to try. He got his gun, plugged it into the wall, hit the trigger and it was off instantly!

Clearly, I was putting more than 450 lb on with a breaker bar/fence post - more like 1000 lb but a 450 lb electric impact wrench made it easy. Don't know what to make of that to this day.

The nut and shaft were fine and there was no Locktite. It did have the tooth washer.
Click to expand...

The clue is impact in impact gun..but that could be duplictaed with club hammer as the torque is applied
 
side note -- I read somewhere that the breakaway torque of an "electric or battery" operated impact gun is about 2X the factory rating. that initial, or quick burst of torque is the key. I know a 1/2" drive 20V dewalt has a 700 foot-pound rating, but the breakaway torque rating is something like 1200 foot-pounds. again, to the OP, good luck.;)
 
One question that I feel compelled to ask... WHY do you need to remove the rotor? Yeah, yeah, I know that the nut/rotor should be easily removable and whatever the issue is , it will have to be corrected at some point. But unless you need to tear the engine down or the alternator is not functioning/rotor needs replacing, do you HAVE to remove it now? Just asking. ;)
 
johnny Lagdon said:
Trying to get the rotor nut off the crankshaft and everything I have tried will not work so far. From the regular up to heat and rattle gun, no movement. It would appear PO has used locktite and it is beaten every method I have tried. Any suggestions? I am perplexed as to what to try next
Click to expand...

A lot of differing suggestions. So where are you with this?

Best.
 
I have never seen loctited fastener that normal hand tools couldn't remove simply with a bit more than 'normal' torque. Loctite usually acts more like a nyloc nut than a "welded" fitting. I have had red-loctited fitting on my original Norton mirrors vibrate loose with no help from me! :) I think a cross-threaded or incorrect thread on the nut is possible though it could be that the fittings have rusted/corroded together if the bike has been stored for many years.

Sadly, I have no suggestions that haven't already been proposed. I would have thought that a decent impact wrench would easily break it loose. :(
 
Not a crank alternator nut, but if it's not moving, time to cut through the nut:
 
Go the other way.

Put a chunk of ice on the nut and get it as cold as you can.
Then....
Tighten the nut with a reasonable amount of pressure using a breaker bar, just don’t overdo it.
Using a BB allows you a better sense of feel than an impact wrench.
This is a good way to break the bonding/lockup...
Now using your breaker bar try unscrewing it...Heat may help...this has worked for me too many times not to offer it up.
 
I don't get it. Lots of people saying split the nut, cut the nut.

But all the ones I have seen are sleeve nuts.

How can you cut the sleeve? An ordinary nut is easy but a sleeve nut ??

You would have to spark erode it maybe?
 
Lineslinger said:
Go the other way.

Put a chunk of ice on the nut and get it as cold as you can.
Then....
Tighten the nut with a reasonable amount of pressure using a breaker bar, just don’t overdo it.
Using a BB allows you a better sense of feel than an impact wrench.
This is a good way to break the bonding/lockup...
Now using your breaker bar try unscrewing it...Heat may help...this has worked for me too many times not to offer it up.
Click to expand...

A CO2 fire extinguisher will produce a big chill. Or pack it with dry ice.

Slick
 
As noted, there is no way to cut a sleeve nut in the configuration as in the Norton crankshaft/rotor. Heat is, of course, very helpful but, as has been noted, you need to be careful with heat depending on what components nearby may be affected.

Re the video: I have worked on a LOT of seized fasteners in big marine diesels as well as cars/bikes, etc. I have found that if I can get the fastener to move back and forth at all, as he did, it WILL eventually unscrew if you work at it.

He says penetrant won't get into the threads and I agree as a general statement. If you just spray a fitting and wait for the stuff to "soak in" so it will just unscrew, that isn't going to happen. BUT If you spray some onto the threads and then rotate the fitting back/forth the penetrant will work itself in slightly with each back/forth movement and each back/forth will result in a bit more more unscrewing. It might be just a tiny fraction of a turn each time but each back/forth will produce more as you continue to wet the fastener with penetrant/work the fitting back/forth. It might take 20 minutes (PATIENCE!) of that but it will come off without requiring that you destroy parts! I've done more of these than I can count, in almost all cases using WD40 even though it's not sold as a penetrant. I always have WD40 handy and it seems to work as well as the expensive penetrants I have tried in the past (and which I no longer purchase).

Unfortunately, the configuration of the Norton rotor/nut makes it essentially impossible to get any penetrant, or very much heat into an area that could help. :(

If the nut/crank are absolutely seized together, the configuration of the sleeve nut/shaft/rotor makes it almost impossible apply enough heat to avoid destroying the rotor. If there is no alternative and the nut MUST be removed to accomplish whatever rebuilding/repair is necessary, it may require that the rotor be sacrificed :( I have never seen a fitting that the "flame wrench" (ox-acetelene torch) couldn't heat enough to allow removal with normal hand tools. The most important issue is to not damage the crankshaft! The rotor and the nut can be easily and inexpensively replaced; the crank...not so much. ;)
 
Re: eventually coming off with pen oil, if like the BMW head above, the innermost threads are seized, you will ruin the rest of the threads and the crank (or head in the BMW) will be toast. I vote for sacrificing the rotor (and the sleeve nut) over perhaps ruining the threads on the crank. Rotor costs much less than a crank.
 
I can see that wiggling back and forth is to the good.. but am puzzled as to what benefit there would be from ice.. important not to lose patience and resort to animal attack.. my own prefared solution would be to put washer or spacer inside socket so that impact bears on the nut not on crank end , apply and maintain about 100 ft lb and keep hitting the elbow of breaker bar with a hammer.. eventually it will turn.. If not then maybe you will have to sacrifice the rotor, certainly cheaper than destroying the crank threads.
 
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oldmikew said:
but am puzzled as to what benefit there would be from ice..
Click to expand...

The cold will reduce the size of the part it touches, same as heat increases the size of the part it touches. The expansion or contraction will create movement against other parts so cooling the nut would hopefully start to reduce the grip of the loctite by relative movement nut to crank.
 
kommando said:
The cold will reduce the size of the part it touches, same as heat increases the size of the part it touches. The expansion or contraction will create movement against other parts so cooling the nut would hopefully start to reduce the grip of the loctite by relative movement nut to crank.
Click to expand...

I have never tried .. but would have thought if the nut shrinks then it would tighten in the threads
 
I would like the OP (Johnny) to tell us why he suspects that loctite was used, other than the nut is stuck. Nobody in their right mind, even a complete hack, would red loctite that nut - it's just not needed. The rotor is keyed with a Woodruff, and there's normally 70 or so ft lbs on that nut. It's not one of the fasteners that comes loose. My gut feel is that the nut is jammed into the rotor, not loctited to the shaft.
 
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