stuck cylinder head nuts

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rjk40
750 GT
Posts: 173
Joined: Thu Dec 05, 2013 10:54 am
Location: Malabar, Florida

stuck cylinder head nuts

Post by rjk40 »

After many iterations over the past couple of days, I have had no luck with loosening the 16mm head nuts on my 860GT.
I have used several applications of fixitright blaster and WD40, I have only gotten one nut to turn slightly, and I believe that the stud turned along with it.
I am beginning to believe that I might have to cut or grind the nuts off the stud and get replacements.

I have used the hot/cold approach as well, to no avail.

I have hammered sideways and down on the nuts and studs.

There is no way, of course, that a bolt/nut splitter will fit into the cramped space.

Maybe I should just keep at it for a few more days.

I have searched the Web and forums and have yet to find someone who has successfully solved the problem on this particular engine, many others, but not this one.

For now, I will just keep pecking away with the methods I have noted.

Short of prayer, any tips will be greatly appreciated.

Regards,
Richard
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Craig in France
Paso 750
Posts: 912
Joined: Tue Mar 23, 2004 3:58 pm
Location: Montpellier, France

Re: stuck cylinder head nuts

Post by Craig in France »

rjk40 wrote:After many iterations over the past couple of days, I have had no luck with loosening the 16mm head nuts on my 860GT <snip>. Any tips will be greatly appreciated.
Richard, you've got to be patient. That said:

1. Don't waste your time with WD40. As an easing oil, it's essentially useless. The best thing is a self-made 50/50 mix of acetone and ATF. But even this will take time - days, weeks, even months :shock: . Keep applying it, liberally and often (use a syringe to make sure it goes to the right place). And be patient.

2. In this situation, the hot-cold trick isn't certain to give you results. It works best with two disimilar metals which expand/contract at different rates. Not the case here. But by all means keep doing it - and repeat it, don't do it just once: hot-cold, hot-cold, hot-cold ... And make sure that the stud/nut get really hot - lots of blow torch. And then flood it again in easing oil ... :)

3. Don't try to ease the nuts free. To break the rust bond, you've got to shock them loose. Put the spanner securely on the nut (get someone to hold it on firmly, if necessary). Then bang the other end two or three times using a heavy hammer. Rest, apply more easing oil, and then try again.

4. Try to tighten the nut first, then undo it.

HTH and good luck! They will yield ... eventually :-D

Craig
rjk40
750 GT
Posts: 173
Joined: Thu Dec 05, 2013 10:54 am
Location: Malabar, Florida

Re: stuck cylinder head nuts

Post by rjk40 »

Thanks kindly, Craig,

I shall keep at it.

Fortunately, as a retiree, I have more time than money (up to a point, of course).

I see mixed comments about the use of heat, some recommending a heat gun only, and others recommending getting the metals almost red hot. The common comment in both is to apply the easing oils while the metal is still hot. I shall try getting the pieces hotter.

My biggest fear, even if I do have to destroy the nuts and replace them, is that the stud turns in the crankcase.

Regards,
Richard
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Craig in France
Paso 750
Posts: 912
Joined: Tue Mar 23, 2004 3:58 pm
Location: Montpellier, France

Re: stuck cylinder head nuts

Post by Craig in France »

rjk40 wrote:I see mixed comments about the use of heat, some recommending a heat gun only, and others recommending getting the metals almost red hot.
I can't see a heat gun working well in this situation, Richard. What you want here is a burst of concentrated heat, focused on just the right spot. However:
1. A heat gun is designed to deliver a distributed heat
2. The very architecture of the engine is designed to dissipate heat ;) .

Hence my recommendation of a blow torch.

Obviously don't go crazy with it - there's still a lot of aluminium around there, melting point +/- 600°C. But steel starts going red hot below this at around 450°C (these temps are approximate 'cos they depend on several variables - the metal's composition, for one thing).
rjk40 wrote:My biggest fear, even if I do have to destroy the nuts and replace them, is that the stud turns in the crankcase.
A wise man would be replacing those nuts anyways, Richard 8) ("Ha'porth of tar ...", 'n all that, you know). If a stud does come loose, it's not necesarily a disaster, but it is more work. So I take your point .... :)
GeoffW
Mariana
Posts: 43
Joined: Sat May 19, 2012 3:01 am

Re: stuck cylinder head nuts

Post by GeoffW »

Something else I've had success with is the combination of the oxy torch on a nut followed immediately by spraying the stud with 'nut freeze' or whatever that spray is called. It's a freeze spray combined with a penetrating lube, you aim that at the stud to cool it whilst the nut is still hot but it's gotta be a quick attack.

(I won't be so offensive as to suggest you double-check that you are turning the nut counter-clockwise...I hate those sort or 'helpful suggestions)
rjk40
750 GT
Posts: 173
Joined: Thu Dec 05, 2013 10:54 am
Location: Malabar, Florida

Re: stuck cylinder head nuts

Post by rjk40 »

Thanks Geoff,

I will certainly try the "freeze spray" in the process. The concept certainly makes sense, and is supported by many others.

And no offense, I did turn clockwise (looking from the top of the stud) just to see if a bit of tightening effort would help the cause, and trusting that the durned things are not reverse threads (I've burned myself on this in the past), do turn counterclockwise to loosen.

Regards,
Richard
rjk40
750 GT
Posts: 173
Joined: Thu Dec 05, 2013 10:54 am
Location: Malabar, Florida

Re: stuck cylinder head nuts

Post by rjk40 »

Hooray!

With two more hot/cold cycles, a bit more easing oil, and the some brisk tapping on the wrench, I was able to get all eight bolts off with no damage to anything.

Thanks kindly to all the folks who gave me great tips.

These forums are a great gift to we who gain from the sharing of info and experience, and my hat goes off to Steve and all of you who share.

Regards,
Richard
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BevHevSteve
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Re: stuck cylinder head nuts

Post by BevHevSteve »

thanks Richard. :rad:
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