Steering stem nut seized - any advice?

[shudnobetter]

I'm unable to shift the steering stem nut on my 1990 3cv. The black domed cap nut between the 2 fork stems. Anxious not to wreck something by applying too much force...any advice welcome.

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I'm unable to shift the steering stem nut on my 1990 3cv. The black domed cap nut between the 2 fork stems. Anxious not to wreck something by applying too much force...any advice welcome.

shudnobetter,

Heat.  Apply heat using a hot-air gun, which makes air hot enough to melt solder.  Use only enough heat to do the job, though.  A hair dryer will not do it, and a propane torch (or any gas torch) will over-do it.  Heat alone is usually sufficient help.  You can also try chemicals - most "liquid wrench" products are just kerosene, with maybe a few other things mixed in.  Apply the solvent and let things sit overnight, then apply heat and tooling in the morning.

[CutterBill]

Sacrifice the nut...

Use an angle grinder to carefully remove the top of the nut. Grind down until you can see the top of the stem and the nut becomes just a threaded sleeve.  Then soak the top of the threads with penetrating oil.  With any luck, the oil will wick down into the threads and you can get the nut off. Don't force the nut. If it still won't work free with oil, use a Dremel grinder to cut thru the sides of the nut and split it.

Been there, done that. Nuts are still available from Yamaha, and cheap. The lower clamp (with steering stem) is not available.  Good luck.

(Photo of a ruined steering stem)

[FJ1100mjk]

Take the bike (if you don't have it all apart already) to an auto or motorcycle repair shop. Have them use an air impact wrench to pop it off.

[shudnobetter]

great,

Appreciate the speedy replies. Think I'll try heat first and go from there.

[CutterBill]

Take the bike (if you don't have it all apart already) to an auto or motorcycle repair shop. Have them use an air impact wrench to pop it off.

See above photo....

The nut is not just tight; it's seized. Forcing it, whether by air or by hand, will only make it worse.

[FJ1100mjk]

See above photo....

The nut is not just tight; it's seized. Forcing it, whether by air or by hand, will only make it worse.

I see no pic from the OP regarding his problem. Either looking at his post on my smartphone, or a laptop. I do see an example pic that you posted.

If the only pic is yours, it for reference only, and may or may not be what the OP is experiencing.

[Pat Conlon]

If heat does not work, in light of Bill's experience, the decision to me is simple.

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If heat does not work, in light of Bill's experience, the decision to me is simple.

Shudnobetter,

I agree with Bill and Pat.  Heat makes the nut physically larger, and it should be all you need to help do the job. 
If the heat does not work, then yeah, definitely, grind slots on each side of the nut, almost to the threads, and split the nut off with a skillful chisel. 
Clean the steering stem threads with a wire brush.  Install the new nut using anti-seize compound.
-

[FJ1100mjk]

You guys crack me up sometimes.

One pictorial example of a steering stem with seized/sheared threads, and we're all supposed to take that as the OP's problem faithfully. As I mentioned, no picture was provided by the OP. Maybe that will come later to settle this all. If it does, and his steering stem nut was indeed seized to the steering stem, so be it. I was only offering advice, which the OP was looking for.

Perhaps:

1. The OP does not possess a breaker bar, to provide sufficient leverage to break the tightened nut loose.

2. When someone cannot break a lug nut loose on a car's wheel, because they do not a tool to provide sufficient leverage to do so, they should they automatically pull out a hand grinder, grind the top of the lug nut off, and put penetrating oil on it. Have any of you ever used a breaker bar or air (or electric) impact wrench in this scenario, and the nut came off without any issues?

The OP stated that he could not break the nut loose, and was apprehensive about using "too much force". Period.

Regardless, if the OP's steering stem's nut is cross-threaded/seized, he's hosed anyways.

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The OP stated that he could not break the nut loose, and was apprehensive about using "too much force". Period.
Regardless, if the OP's steering stem's nut is cross-threaded/seized, he's hosed anyways.

FJ1100mjk,

I think the OP will do just fine.  His caution with a stubborn nut is respectable, in my book.  If he has to split a nut off, he may need to brush the threads clean, or even chase them with the correct die, but the stem should not be a total loss.  Rash action could well result in the picture that you referenced, of course.

Even in the worst case, with the steering stem ruined, it might simply be time to make lemons into lemonade.  A complete modern steering assembly (stem, forks, brakes, and a 17" wheel) from the recyclers could be an easy and cheap remedy, there.  It might be cheaper than the other alternatives, and a 17" front wheel gives the rider a lot more tire choices.

Hang tough, I want to hear how the OP manages there.
-

[CutterBill]

Perhaps:  1. The OP does not possess a breaker bar, to provide sufficient leverage to break the tightened nut loose....

FJ1100mjk...
Indeed, perhaps I over-reacted.  That particular nut is torqued to only 80 ft/lbs.  If it's stuck, it might take perhaps... 100 ft/lbs to loosen?  That much torque can easily be achieved with a standard 1/2" drive ratchet wrench.  So I just assumed that the OP had the tools at hand to get the nut off.  I assumed that he had tried very hard, but that the nut simply wouldn't budge.  Or worse, moved slightly then stopped moving.  Which is never a good sign.  But maybe you're right; maybe he just didn't realize that it takes a bit more than a "bump" to break that nut loose.

So let's say that you're right and the nut is merely tight and not seized. Taking my suggestion of grinding off the top of the nut would cause him to waste about an hour and $5 for a new nut.  Not much damage there.

But what if you're wrong and the nut is seized? Taking your suggestion and using brute force would result in a ruined steering stem.  Now he has to find a good used stem and pay a not insignificant sum for it, take the front of the bike apart and install it.  For a newbie, probably several weekends worth of work.  And money which could be better spent on petrol and beer.  Quite the chore.

Given those two options, do you choose Door #1, or Door #2?  Me? I'll go with the safe bet every time.
Bill

[FJ1100mjk]

FJ1100mjk...

I over-reacted. Yep.

So I just assumed that Yep.

I assumed that he had Yep.

But maybe you're right Not necessarily.

So let's say that you're right Not needed.

Me? I'll go with the safe bet every time. Who wouldn't?

Bill

Bill:

I don't care anymore. I'm done. Seriously.

[FJ_Hooligan]

Next time use Anti-Seize on it!

[FJmonkey]

Next time use Anti-Seize on it!

Now that's just mean...