bike reassembly bolt and fastening treatements

Hi realised I had to wrestle with even the title for this post/question.
What I would like to learn, is the following:

What would be the ideal collection of fluids, glues and greases that one would require in rebuilding a motorcycle: (mechanically only)

I currently have the following:
- Loctite (dont know which type I have)
- Copper paste (as far as I know prevents bolts seazing when under high temp)
- standard grease
- silicone grease (for use instead of normal petroleum based grease when rubber parts are involved such as o rings, etc...)

In my simplistic world a dab of grease is always a good idea when rebuilding mechanical things, but on a motorcycle, vibration and other factors mean that some more carefull choice of chemicals may be required.

I am hoping to tap the immense intellectual capital residing in this forum to learn as much as I can on this subject.

Many thanks in advance.

 

use the blue loctite red lock tite needs heat and you can snap bolts when trying to remove them

copper not good for aluminim , I use nickle lube paste

i use the red high temp grease

good stuff for any place rubber needs to be installed.

when using loctite torque specs change there is a thread or posting on this maybe in the info overload

any time you use stainless steel bolts you need to add loctite or anti seize paste to prevent seizing with aluminium

atf and acetone 2 to 1 ratio to free up frozen pistons/rings any bike i get gets this treatment as the first step when motor has not been turned in a few years

 

Beer.

 

That goes without saying! But thanks for reminding.

 

Surprisingly, most fasteners on the bike do not require the use of thread-locker fluid (your service manual will specify which ones do), but if used where not specified, I would use the purple (semi-permanent) which is even "weaker" than the blue formula. But truthfully, I would use anti-seize rather than locking fluid on most fasteners, seizure is the big problem, not fastener loosening.

NOTE: the use of anti-seize compounds will result in a TORQUE-MULTIPLYING EFFECT……..the result of a reduction in friction between the threaded contact points……and thus fasteners treated with anti-seize compound should have their torque values reduced by at least 10-15% when installed into steel material, and up to 25% into aluminum materials or other “soft” metals” (such as spark plugs into cylinder heads, or almost any other type of fastener into the engine) …… note that this rule applies only to service manual torque specifications on fasteners that are not indicated to be treated with anti-seize fluid by the factory …. if the factory manual specifies the use of an anti-seize coating, then the specified torque value for that fitting already takes into account the “reduced torque” necessary.

http://raskcycle.com/techtip/webdoc14.html

http://www.cncexpo.com/MetricBoltTorqueNm.aspx

http://www.bmwmotorcycletech.info/sparkplugs.htm

http://www.antiseize.com/pdf/torque_specifications.pdf

 

simple question, why? what happens?

 

Thanks guys for the information so far.
I have been looking through the service manual and I have as yet to come across a reference to any anti seize or loctite, etc...
Does this mean that there are not so many screws or bolts that need it or are my eyes lazy?

This is the manual I am working with...

 

locktite is used in the forks
you can also use it where there are tabs such as the disc brake and sprockets if you do not use the fold tabs.

the fsm and haynes does not give all the info. it is written with the idea that the mechanic has some knowledge of the work.

Aluminum will be very susceptible to galvanic corrosion in contact with copper, assuming that the two metals are also in contact with a common electrolyte (such as water with some ionic content.)

 

^that, and aluminum becomes more brittle the longer it is in contact with copper (though that does depend on which alloy of aluminum).


As for the use of threaclocking compound: I recently found an odd-shaped machine screw in my driveway as I was bending down to inspect the tires. I hadn't noticed it laying there before, so I did a quick once-over the whole bike. Turns out that it was one of the screws that secure the helmet and seat lock to the frame. That lock (to my knowledge) has never been removed. This is one part of why I use medium-strength Locktite on every fastener that I remove. The other is to keep corrosion at bay so the fastener will come off when I need it to.

So why do factories not use it on all the fasteners of their products? Cost. On a per-unit basis a manufacturer is saving hundereds of thousands of dollars over a model run by letting that detail be the customer's responsability. So it's used in critical areas only; areas where a loose fastner will cause a warranty claim or an injury.
They use it on all the machinery that has to keep running in the factories though. Downtime costs money too.

 

If I remember one of the frequent maintenance checks in the owners manual is to ensure all bolts are tight, etc.

 

with special attention to any bolts and screws you have recently loosened

 

Just remember this number. 20%. That's the maximum amount of thread surface contact present on a threaded fastener (more typical is 10-15%). The rest is airspace.

 

We are honing down onto the reason I put this post up in the first place.
I am doing a complete rebuild of an XJ900 and also have another identical one that is running (most of the time)

Had the speedo apart on the running bike to change a bulb and then got carried away and took the thing completely apart to see what makes it tick.
Rebuilt the thing and then after a few weeks the speedo faceplate came loose and made my speedo useless. 2 little screws worked themselves loose with the vibrations.

The power of vibration!

That go me to think about the general vibration of the bike and what a minefield it would be to avoid a hard to get at bolt from working itself loose.
I know the torque settings will go a long way to preventing this, but the application of products like loctite seem to be the trick.

But then there is the converse issue of seized bolts as well! While trying to remove the 2 of such SOB bolts from this old girl has taught me a healthy respect for a siezed bolt and their ability to derails any mechanical task.

So as I am slowly rebuilding this bike, I do not want to lay too many landmines for myself in the future. Correct re-installation of all fixing bolts is the most basic step I can take to that ends.
Also replacing the bolts with new ones where practical seems like a good idea as well. (on that note, any opinions on pros and cons re nickel plated steel vs Stainless steel fasteners. Technical choice points not cost)

Thanks K-Moe for the practical advice.
Sound like I should use mid strength blue or weaker purple Loctite on everything.
Off to the shop again!

By the way can any of you imagine the application of the Copper paste on the bike rebuild and if so, where?

 

I imagine after reading up a little on how Loctite works, that it is the other 80% of this surface area, where Loctite is doing its magic.

 

Found this guide on Loctite products application on Motorcycles.
http://www.loctite.ph/php/content_data/LT4460_Motorcycle_Application_Guide.pdf

 

Technically a fastener (in critical applications) should only be torqued to spec once and then never used again. In a past life we would rebuild large die sets loaded up with carbide tooling with less than .001" shear clearances. The last thing you wanted to happen was to have a bolt vibrate out and dance through the die, or have a component slip out of position. And yet we still had failures . . . .

So with that being said I think you are wise to replace fasteners wherever you feel that if it were to back out you would be really bummed or worse injured.

Material to use? That is tricky, some say that stainless steel will 'corrode' with aluminum and ultimately bind the bolt to its hole (unless you use anti-seize - but now you have a 'wet' thread and torque values change). I use stainless fasteners quite a bit on my 650, but also a huge fan of anti-seize, I have not noticed any corrosion issues and haven't had any failures. I would tend to think the grade of the bolt would be more important than material. There can be a lot said about fasteners and their design for different applications . . . almost too many options for the critical mind to be allowed to come to an easy answer - i.e. - whether the crotch of a thread has a radii can have an impact on strength in an environment with vibration (that was another past life lesson - punch bolts that get torqued to 175 ft/lbs MUST have a radii'ed crotch or they will fail).



<edit>
The Loc-Tite link is a beaut.

 

Yes. It fills the airspace, preventing moisture intrusion, and the corrosion that results.