another grease question: bolt threads

I can use a touch of just any old grease to lube bolt threads, right?
E.g. the bolts attaching the slave cylinder to the tranny. Or should I
avoid this so as to lessen the risk of over-tightening them? I do plan
to use a torque wrench. While I'm careful, I sure don't want to run the
risk of stripping out an aluminum block.

There's a grease specifically designed to prevent rust around bolt threads. It's
conventionally called "Anti-seize" and has been around for decades in the auto and
many industries that have machinery.

There are a few different grades of "Anti-seize." I buy the grey stuff (which is
perhaps the most frequently used) from Autozone or whoever has the cheapest. Read the
labels and see if it has commentary about temperature applications.

A few bucks for a small tube. A few bucks more will buy you a nice-sized can. Only
takes a little.

Anti-seizing bolts won't mess up the torque you apply.

"Abeness" > wrote
> I can use a touch of just any old grease to lube bolt threads, right?
> E.g. the bolts attaching the slave cylinder to the tranny. Or should I
> avoid this so as to lessen the risk of over-tightening them? I do plan
> to use a torque wrench. While I'm careful, I sure don't want to run the
> risk of stripping out an aluminum block.

Caroline wrote:
> There's a grease specifically designed to prevent rust around bolt threads. It's
> conventionally called "Anti-seize" and has been around for decades in the auto and
> many industries that have machinery.

Thanks, Caroline.

"TeGGer®" > wrote
> "Caroline" > sprach im
> > Anti-seizing bolts won't mess up the torque you apply.

> Yes it does. Anti-seize and oil both reduce the friction of the threads
> against each other.

It depends.

1.
If it's an old, somewhat rusted bolt, it may very well noticeably reduce
the friction between male and female threads. And this is for the better.

2.
If it's a brand new bolt, the effects of the lubricant on static friction
are going to be negligible.

Static friction. Go study up on it.

> If you use anti-seize, lower your torque wrench setting
> 10% to compensate for loss of friction.

Don't do this. Final, torqued clearance between threads is not affected by
anti-seize.

> Copper-based Loctite C5A is better than the aluminum compounds, such as
> Permatex 133H.

But may be a waste of money, depending on the particular application.

TeGGer® wrote:
> "Caroline" > sprach im
> nk.net:
>
>
>
>>Static friction. Go study up on it.
>
>
>
>
> Static friction is the force you need to overcome when breaking a bolt
> loose. It has nothing to do with *dynamic* friction, which is what you
> encounter when you tighten a bolt down.
>
> Static friction is why that crank bolt is so hard to get loosened.
>
> Dynamic friction is most definitely affected by lubrication on the threads.
> It's the reason why Honda warns against using any lubricant at all on the
> threads of the crank bolt.
>
> If you use anti-seize on a bolt, you risk reducing dynamic friction to the
> point that your torque wrench will not show a correct reading, and you risk
> either overstretching the bolt or stripping the threads, hence the
> reduction in torque reading by 10%.
>
> Even that 10% is dependent on how much lubricant you used. Use a small
> amount of one kind, and it will make little difference. Use a lot of
> another kind and it may reduce dynamic friction by half. As a general rule,
> 10% reduction is good.
>


i believe you both

Caroline wrote:
> "TeGGer®" > wrote
>
>>"Caroline" > sprach im
>>
>>>Anti-seizing bolts won't mess up the torque you apply.
>
>
>>Yes it does. Anti-seize and oil both reduce the friction of the threads
>>against each other.
>
>
> It depends.
>
> 1.
> If it's an old, somewhat rusted bolt, it may very well noticeably reduce
> the friction between male and female threads. And this is for the better.
>
> 2.
> If it's a brand new bolt, the effects of the lubricant on static friction
> are going to be negligible.
>
> Static friction. Go study up on it.

nope, tegger has it on this one caroline...

>
>
>>If you use anti-seize, lower your torque wrench setting
>>10% to compensate for loss of friction.
>
>
> Don't do this. Final, torqued clearance between threads is not affected by
> anti-seize.
>
>
>>Copper-based Loctite C5A is better than the aluminum compounds, such as
>>Permatex 133H.
>
>
> But may be a waste of money, depending on the particular application.
>
>

"TeGGer®" > wrote
> "Caroline" > sprach im
> > Static friction. Go study up on it.
> Static friction is the force you need to overcome when breaking a bolt
> loose. It has nothing to do with *dynamic* friction, which is what you
> encounter when you tighten a bolt down.

When one is doing the final torquing of a bolt, static friction has
everything to do with it.

> Static friction is why that crank bolt is so hard to get loosened.
>
> Dynamic friction is most definitely affected by lubrication on the
threads.

> It's the reason why Honda warns against using any lubricant at all on the
> threads of the crank bolt.

Nope. http://www.honda.co.uk/owner/AccordManual/400/5-36.pdf page 2,
"Apply oil to the bolt threads."

In addition, during operation the crankshaft pulley bolt heats and so
stretches (expanding from the heat), allowing the crankshaft's rotation to
tighten it. Thus after a few years of operation one has the notoriously
tight crankshaft pulley bolt, experiencing torques far in excess of the
torque the technician applies when replacing the belt.

snip
> As a general rule, 10% reduction is good.

This is an old wives' tale.

You also have to think about
1. precisely where the anti-seize ends up on the bolt's threads
2. what the purpose of anti-seize is.

What surfaces is anti-seize protecting from rust buildup? Not the surfaces
in closest contact.

Now there are applications where anti-seize is specifically prohibited, but
they're rare, and from my reading it's often or always due to a concern
other than overtorquing, such as the stuff chipping off when it's dry and
contaminating something or another.

Lastly, you're omitting the reality that anti-seize overcomes or
compensates for existing rust/detritus on a bolt. To say it somehow 'way
overcompensates' for it (e.g. reducing thread dimensions somehow), is some
kind of wild guess.

Caroline
"20+ years with anti-seize."

"Caroline" > wrote
> "TeGGer®" > wrote
> > It's the reason why Honda warns against using any lubricant at all on
the
> > threads of the crank bolt.
>
> Nope. http://www.honda.co.uk/owner/AccordManual/400/5-36.pdf page 2,
> "Apply oil to the bolt threads."
>
> In addition, during operation the crankshaft pulley bolt heats and so
> stretches (expanding from the heat), allowing the crankshaft's rotation
to
> tighten it. Thus after a few years of operation one has the notoriously
> tight crankshaft pulley bolt, experiencing torques far in excess of the
> torque the technician applies when replacing the belt.
>
> snip
> > As a general rule, 10% reduction is good.
>
> This is an old wives' tale.

Ugh. Strike this. I stand corrected on a few important points. Some
reputable sources support Tegger's basic contention. The focus for cars
tends to be (new) spark plug threads, but maybe this is only because this
is where the DIYer is most likely to encounter problems. E.g.

"Most threads on spark plugs designed for aluminum head applications are
precoated to reduce the risk of thread damage. Even so, some technicians
apply a drop of antiseize compound to the plug threads before they go in
for added insurance. General Motors, however, does not recommend this
practice because antiseize acts like a lubricant and may allow the plugs to
be overtightened - which can damage the threads. GM's advice is to reduce
the tightening torque on the plugs 40 percent if antiseize is used on the
threads."

-- Import Car, "Spark Plug Technology Charges Forward," Larry Carley, May
1999

From another source, take two brand new identical bolts. Lube one and keep
the other dry. Torque each to X ft-lbs. Measure the bolt tension. Bolt
tension (= a certain amount of "pull" in pounds on the bolt) is what the
goal is. Torque accomplishes this but indirectly, so to speak.

Dry, the bolt tension will by Y.
With lubricant, the bolt tension is > Y.

Yes, it's due to reduced friction. Call it static or dynamic. It's less.

With an older bolt that is being re-used, I would hesitate to say whether
the prescribed torque should be adjusted. Galling, for one, is likely to be
present, and the lubricant may compensate for this 'just enough.' So I'd
argue (for now), it's a guess as to whether the prescribed torque should be
adjusted.

One may speculate as to why the Honda manual cited above says put a drop of
oil on the crankshaft pulley bolt. E.g.
1. The prescribed torque assumes the bolt has a drop of oil on it.
2. A drop of oil does not significantly affect the tension in the bolt when
torqued to spec.
3. The authors know the bolt will be tightened further by the crankshaft
over time.

Then too I'm not eager to assume prescribed torques (like those in Chiltons
or at the UK site) assume one is not using anti-seize on new bolts. Oxygen
sensor directions say to use a particular antiseize (included with the
sensor in some or all cases). The manuals say then torque to such-and-such.

Sorry Abeness. At this point I can draw only from my own experience: Except
for spark plugs, anti-seize early and often, then torque to spec (without
adjustment).

Caroline wrote:
> Sorry Abeness. At this point I can draw only from my own experience: Except
> for spark plugs, anti-seize early and often, then torque to spec (without
> adjustment).

Well, I've followed this discussion with interest, and I'm still
confused. It makes perfect sense to my mind that lubrication would
affect the amount of torque to apply, because it reduces friction,
thereby making it easier for the bolt threads to slide on and "pull" the
threads of the hole (and therefore strip them with less torque). I don't
know why a bolt would be any different than a spark plug: they both have
threads, and screw into the engine block--or in this case the tranny
housing.

Where is a mechanical engineer when you need one? I would assume,
perhaps erroneously, that if Honda specified a drop of oil on the
crankshaft pulley bolt but not for other bolts, that the torque
specified for other bolts is that prescribed for non-lubed threads.
Whether that is teh case or not would be anyone's guess. Perhaps I'll
try to contact Honda engineering to inquire.

In the meantime, I suspect I'll do what I usually do in these cases: be
careful, and sensitive to the "feel" of the situation. Truth is, I can
tighten the sucker to a reasonable degree, then check it after a few
days' use and see if it's still tight. If not, I'd tighten it a tad more.

Caroline wrote:
> Sorry Abeness. At this point I can draw only from my own experience: Except
> for spark plugs, anti-seize early and often, then torque to spec (without
> adjustment).

Well, I've followed this discussion with interest, and I'm still
confused. It makes perfect sense to my mind that lubrication would
affect the amount of torque to apply, because it reduces friction,
thereby making it easier for the bolt threads to slide on and "pull" the
threads of the hole (and therefore strip them with less torque). I don't
know why a bolt would be any different than a spark plug: they both have
threads, and screw into the engine block--or in this case the tranny
housing.

Where is a mechanical engineer when you need one? I would assume,
perhaps erroneously, that if Honda specified a drop of oil on the
crankshaft pulley bolt but not for other bolts, that the torque
specified for other bolts is that prescribed for non-lubed threads.
Whether that is teh case or not would be anyone's guess. Perhaps I'll
try to contact Honda engineering to inquire.

In the meantime, I suspect I'll do what I usually do in these cases: be
careful, and sensitive to the "feel" of the situation. Truth is, I can
tighten the sucker to a reasonable degree, then check it after a few
days' use and see if it's still tight. If not, I'd tighten it a tad more.