Why does Honda have us replace bolts?

SMSW

Joined
Sep 4, 2013
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Cleveland
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2010 ST1300
Honda calls for replacing the upper rear shock bolt (and presumably, but it is not clear in the manual) nut. However, my service manual does NOT specify a new nut and bolt for the lower shock mount. Why?????? Both are torqued to the same spec so saying one is stretched would mean the other is as well. Loading on the upper will be the same as on the lower so one will not fatigue more. Might this have been a mistake on Honda's part? If Honda trusts mechanics to use Moly on splines and grease elsewhere, why are we not trusted to apply a thread locker where extra protection against vibration is required?

So many questions. So little time.....
 
mostly safety reasons, to avoid critical fastener failure, and lawsuits.
 
That is an excellent question.

A little more insight into the difference between the upper and lower mounting bolts: I once ventured into a part of the manual that I had never looked at before, and your query reminded me that this section may reveal some further information. So I delved back in there and had a look. It sure does:

In the General information section, it describes the various characteristics of key fasteners - and in the Rear Wheel Suspension section, it lists the two nut and bolts for the upper and lower suspension fittings.

The size and torque are the same for both, but in the remarks colum, it says NOTE 6 for the upper, and NOTE 5 for the lower.
So you then go hunting for what Notes 5 and 6 mean.

A couple of pages earlier is an easy to miss list, headed NOTE:

5. U-Nut
6. ALOC bolt/screw:replace with a new one.

So there we have it, all perfectly clear.

You can then go hunting for ALOC and U-Nut.

Google search reveals the most likely explanation - A Fujilock Unut is one of those nuts that has a stainless steel spring device on the outside thread, to help prevent the nut from turning.

ALOC is anybody's guess as to what it stands for. Google searches reveal only opinions, and the dealers that I have asked don't know either - but every ALOC bolt that I have seen from Honda has a thread locking compound already applied to the bolt threads. But that is a fairly limited sample size.

I have never undone either of these two bolts, but just by looking at the manual, if the bolts are employing two different locking mechanisms as would appear to be the case, and they are both the same size thread (the general info quotes 10mm for both) - then I wonder if it is possible to re-fit the bolts and accidentally switch the nuts - ie make the error of fitting the U-Lock nut to the upper ALOC bolt. This would leave the lower mounting bolt with no thread locking mechanism to prevent the nut/bolt from turning.

And have I just solved the alleged Pan / ST1300 weave issue?

[edit]From another Google search, it appears that ALOC is now a registered trade mark of Bowers and it seems to relate to 'metal fasteners, namely quarter turn fasteners'. This trademark appears to have been filed in 2009. So when my manual was written in around 2002/2004, I guess that the term ALOC was not a registered trade mark. Whatever - it means something different now, and I just hope that no-one goes buying a quarter turn fastener to hold their brake calipers and rear suspension in place !

I wonder if there are any Honda shop manuals that are published after 2009, and what terms they use for these 'ALOC bolts'. [/edit]
 
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I think it stands for, it makes Honda, "A Lot Of Cash".
+1 Heathy it's a bolt or fastening pre coated with a locking agent. Hence advised to change for the reasons already given.
You could of course just apply your own correct locking agent as Honda are rich enough already.
Hope it helps.
Upt'North.
 
Safety - in replacing critical fasteners with that brown looking thread sealant or whatever it is on them on them.
Have I ever replaced them? Just the shock bolt, but only because I had one handy.
The front caliper bolts and the rear caliper stop pin are all original. I clean them off with a wire brush, apply blue Loctite, and re-use.
 
There are a number of bolts, nuts and washers (like on gas lines & hydraulic lines) that they say to replace every time you remove them.

Personally I think it is for their own good. If a used bolt failed, a dealer could be held responsible (as in Liability). So they go along the line of being safe, than sorry.

If a bolt needs torquing, I torque it, but I only replace them when they are looking ugly (like a stripped head!
 
I guess some of the fasteners come with pre-applied thread locker and they don't trust us to re-apply some or perhaps fear the wrong type would be used. I ran into a case with my daughter's car (Toyota Paseo) with the exhaust system. We bought it used and discovered an exhaust leak where the forward pipe bolts to the manifold. The gasket had been burned through and about half blown out. Easy fix right? Go buy a new gasket and cinch it all up again - wrong. A few weeks later it blew out again. Replaced it a second time, this time with some thread locker on the nuts. Wasn't sure that would work given the temperatures. Sure enough it blew out again. While pulling it apart I sent said daughter to go buy yet another gasket. I was planning to try something different this time, but she called me from the dealer and said they told her not to re-use the exhaust system nuts. That sounded nuts, but as it wasn't much $$ I told her to grab some while she was there. When I looked at them I noticed they were deliberately made out or round, slightly oval shaped. Evidently this was to provide some kind of locking function upon first installation. Once rounded by use, that function is evidently lost. I dutifully used the new nuts and the problem stayed fixed after that.
 
On my 2003 FZ1 everything was locktighted from the factory. EVERYTHING! I had to borrow snap on tools to keep from rounding bolt and nut heads. This made me very ANGRY!

So years and years ago before I had a service manual on my 13 I removed the rear caliper to do a tire change and some ***#$%^ had locktighted the 15mm bolt! Son of a *****! I was so angry all over again! I put the bolt back even with a little locktight on it. But after several tire changes there wasnt any left at all.

Then I got a SM and saw the part about buying a new bolt every time from Honda! With locktight on it. That was 45,000 miles ago! **** *******! I never buy new bolts when they say to and Im 62 this year. IMHO bolts come loose because someone failed to properly tighten them. Maybe there are one or two exceptions...
 
Thats it! Note to loctite advocates...if you apply loctite and forget to properly tighten the fastener.....its still gonna come apart! :)

Whenever I have something apart I make it a point to leave the wrenches I used on the seat when finished. I go over the fasteners again when I come back to the bike to ride it. Because Ive made mistakes and I dont want to get killed. And a month later I will go over everything AGAIN.

Remember when owners manuals used to say Check the tightness of all fasteners? Like every 6000 miles? Once a year I go over everything. Im pretty sure they dont say that anymore....

That 15mm bolt on the rear brake caliper if it backs out is going to hit the wheel. Its only got 1/4 inch to move too. But using my protocol Ive never found it loose...
 
There are 2 reasons why the loc-tite sealant is used one is keep it from vibrating loose , twisting force (lower shock twists more than the upper) and the other is corrosion protection of the threads. The corrosion part was told to me by a Mopar engineer.
 
Trump said:
IMHO bolts come loose because someone failed to properly tighten them.
Click to expand...

I guess that in an ideal world that would be true. But wasn't there a suspicion that some mounting bolts became loose as a result of heat expanding the bolts and allowing them to become loose, which then required different tightening procedures to be adopted ? I thought that I had read that somewhere. I always torque bolts properly, and I always go round and check them as required in the service schedule. The existence of nyloc nuts, spring washers, castle nuts and cotters, U-nuts, thread locking compound and wired nuts would suggest that it is possible for things to work loose over time regardless of whether they were torqued correctly.
 
jfheath said:
I guess that in an ideal world that would be true. But wasn't there a suspicion that some mounting bolts became loose as a result of heat expanding the bolts and allowing them to become loose, which then required different tightening procedures to be adopted ? I thought that I had read that somewhere. I always torque bolts properly, and I always go round and check them as required in the service schedule. The existence of nyloc nuts, spring washers, castle nuts and cotters, U-nuts, thread locking compound and wired nuts would suggest that it is possible for things to work loose over time regardless of whether they were torqued correctly.
Click to expand...

You are quite correct. Here is a good resource.
http://www.boltscience.com/pages/vibloose.htm

A bolt, properly sized, in a properly sized hole, loaded only on tension, and with proper amount of preload, should stay put. The threadlocker, safety wire, Nordlock washers, are all methods of ensuring it does.

An additional method is the stretch, or more properly known, torque to yield bolt. The bolt is literally stretched until it is deformed to apply the proper preload. Since the deformation is permanent, they must be replaced after every use.l (once it starts to deform/yield, there is very little room left for additional deformation before rupture occurs).
 
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Al-Hala said:
You are quite correct. Here is a good resource.
http://www.boltscience.com/pages/vibloose.htm

A bolt, properly sized, in a properly sized hole, loaded only on tension, and with proper amount of preload, should stay put. The threadlocker, safety wire, Nordlock washers, are all methods of ensuring it does.

An additional method is the stretch, or more properly known, torque to yield bolt. The bolt is literally stretched until it is deformed to apply the proper preload. Since the deformation is permanent, they must be replaced after every use.l (once it starts to deform/yield, there is very little room left for additional deformation before rupture occurs).
Click to expand...
Agreed. The flywheel bolt on my KLR is final torqued to 140 ft/lbs, and is to be replaced with each removal. And I do.
The caliper bolts on our STs (23 ft/lbs) and brake stop pin (51 ft/lbs, big bolt) are not going to stretch much, if at all at those relatively low settings. My opinion is they are recommended for replacement strictly due to the locker/sealant brown stuff that comes on them. I Just reuse and use blue Loctite.
 
jmcarruth said:
Agreed. The flywheel bolt on my KLR is final torqued to 140 ft/lbs, and is to be replaced with each removal. And I do.
The caliper bolts on our STs (23 ft/lbs) and brake stop pin (51 ft/lbs, big bolt) are not going to stretch much, if at all at those relatively low settings. My opinion is they are recommended for replacement strictly due to the locker/sealant brown stuff that comes on them. I Just reuse and use blue Loctite.
Click to expand...

Agreed. I've done similar, with low torque fasteners on my vehicles. The real important reason to replace the yield bolts is that while one continues to turn the bolt past yield, most of the torque is continuing to elongate the bolt, not adding more preload. Go too far, and the bolt breaks.

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I've never had a dealer or tire shop actually replace those caliper bolts. Loctite maybe...
 
jfheath said:
I guess that in an ideal world that would be true. But wasn't there a suspicion that some mounting bolts became loose as a result of heat expanding the bolts and allowing them to become loose, which then required different tightening procedures to be adopted ? I thought that I had read that somewhere. I always torque bolts properly, and I always go round and check them as required in the service schedule. The existence of nyloc nuts, spring washers, castle nuts and cotters, U-nuts, thread locking compound and wired nuts would suggest that it is possible for things to work loose over time regardless of whether they were torqued correctly.
Click to expand...

Yes they do have lock washers and cotter pins. But where are all these loose fasteners everyone keeps talking about? :confused: Im 62 and the only loose one I ever found was the rear axle nut of my ST13. The Honda dealer had the wheel off. You could turn the nut off with just your hand on the 27mm socket. For 4 thousand miles it was like that! They never tightened it. (I hear they use torque wrenches) Ive removed a million cotter pins in my life time. Not one had a loose nut under it. Have you ever found one? :confused:

As a private pilot I see some wired on nuts on easy to get to things like the propeller. Maybe one in a hundred fasteners have wires to secure them. But if they arent easy to get to....no wires. thats 99% of the fasteners on my airplane. The sheet metal screws that hold the inspection covers in place arent possible to wire in place. They dont use loctite on em either. Been flying since '83. Theres hundreds of sheet metal screws on an airplane. Never saw a loose one. Not one.

If you fellers see a loose nut take a picture will ya?
 
Many vehicles and equipment extensively use TTY bolts, many in critical components. My VWs use them everywhere for suspension, engine mounts and all through the timing belt system. Reusing TTY bolts in critical components is foolish and visiting a owner's forum will quickly show that "recycling" said fasteners has resulted in engines "dropping", valve timing components failing (catastrophic engine destruction) and many various related fails. Not torquing them properly is as close to failure as using them over again.
If a service manual requires a new fastener for a critical component, do it.
 
jettawreck said:
Many vehicles and equipment extensively use TTY bolts, many in critical components. My VWs use them everywhere for suspension, engine mounts and all through the timing belt system. Reusing TTY bolts in critical components is foolish and visiting a owner's forum will quickly show that "recycling" said fasteners has resulted in engines "dropping", valve timing components failing (catastrophic engine destruction) and many various related fails. Not torquing them properly is as close to failure as using them over again.
If a service manual requires a new fastener for a critical component, do it.
Click to expand...

I don't wrench on as many things as I used to, so my experience with this topic is very limited. The only TTY bolts I've come across were on the cylinder head of my 1990 5-series BMW. Those bolts required a moderate initial torque (20-25 ft-lb) to snug them up, then they were spec'd to an angle torque of an additional 90 degrees for the TTY phase. I seem to recall the bolts were also necked down a bit between the head and the threads, so they looked different as well. Between the angle torque spec, plus the different appearance, there were clues that these were not just ordinary bolts. And they had torx heads too.

Is it common to come across TTY bolts that look just like any other fastener, and if so, how do you determine a particular bolt is TTY? I'm guessing that just because the service manual says "use a new one" that does not necessarily imply a TTY bolt that will positively fail if re-used.
 
Al-Hala said:
...An additional method is the stretch, or more properly known, torque to yield bolt. The bolt is literally stretched until it is deformed to apply the proper preload. Since the deformation is permanent, they must be replaced after every use.
Click to expand...
I strongly suspect this is why Honda wants us to replace that specific bolt - it is a torque to yield bolt. This type of fastener is common in safety-critical applications.

Michael
 
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