crank bolt tightening debate

Jim, I don't cite rolled vs. cut threads as evidence of some kind of
ratchet mechanism, the images were simply not well drawn. I was
citing the mechanisms that cause the bolt to wind inwards caused by
they way the bore is tapped and the effects of the pulley.

Galling is possible on the exhaust bolt since they don't require lubricants.
Once locked together you will notice the extreme "snap" upon release. O2
sensor are one the parts that can benefit from the anti-seize compound to
prevent galling. On some areas on the exhaust system, self locking nuts
are used instead.

Good work for showing what I should fix. I probably have to add better
sketches to visualize a theory and avoid further confusions. Several
sections are fixed based on your input and others not pertaining to the
crank bolt is eliminated.

< snip>

 

Same thing on my angle grinder, my right hand and left hand radial arm
saw. The bolt/nut are screwed in the opposite direction of the spinning
blade. Even finger tight the bolt/nut will tighten (spin inward) over time.

This is caused by (my theory) the force of acelleration of the motor is
stronger than the inertial mass of the blade. Another words, the blade
wants to sit still. Now, if you look at the face or washer of the bolt you
realize that it has a greater surface area contact than on the other side
of the blade. The greater surface area (should not be oil or otherwise
the bolt won't tighten) is actually moving. However, the threads should
be oiled to prevent galling. I believe the same principle is used on the
crank pulley.

 

Jim, I don't cite rolled vs. cut threads as evidence of some kind of
ratchet mechanism, the images were simply not well drawn. I was
citing the mechanisms that cause the bolt to wind inwards caused by
they way the bore is tapped and the effects of the pulley.

Galling is possible on the exhaust bolt since they don't require lubricants.
Once locked together you will notice the extreme "snap" upon release. O2
sensor are one the parts that can benefit from the anti-seize compound to
prevent galling. On some areas on the exhaust system, self locking nuts
are used instead.

Good work for showing what I should fix. I probably have to add better
sketches to visualize a theory and avoid further confusions. Several
sections are fixed based on your input and others not pertaining to the
crank bolt is eliminated.

< snip>

 

As I said before, the il is a crude friction stabilizer. It is common for
high-stress bolt situations to specify friction stabilizers, either as a
coating, or as user-applied materials.

The bolt on your crank pulley is NOT "self tighetening".

Whatever the cause of the face wear (the face isn't oiled, remember), it
isn't moving.

 

As I said before, the il is a crude friction stabilizer. It is common for
high-stress bolt situations to specify friction stabilizers, either as a
coating, or as user-applied materials.

The bolt on your crank pulley is NOT "self tighetening".

Whatever the cause of the face wear (the face isn't oiled, remember), it
isn't moving.

 

Totally different application.

Honda is just about the only manufacturer whose bolts run in a tightening
direction. Everybody else has bolts that run in a LOOSENING direction, and
these DO NOT COME LOOSE IN USE.

Everybody elses' bolts are the same as Honda's, and are torqued to similar
tensions.

 

Totally different application.

Honda is just about the only manufacturer whose bolts run in a tightening
direction. Everybody else has bolts that run in a LOOSENING direction, and
these DO NOT COME LOOSE IN USE.

Everybody elses' bolts are the same as Honda's, and are torqued to similar
tensions.

 

What muddies the comparison is that the cars were both old enough to have
been through at least one timing belt change, so we don't know how diligent
the mechanics were about retightening to the spec'd torque. It could be that
the one who loctited the bolt also wimped out on the torque, relying on the
loctite to hold the bolt. (Not good practice, but it happens.)

I'm completely undecided on this debate.

Mike

 

What muddies the comparison is that the cars were both old enough to have
been through at least one timing belt change, so we don't know how diligent
the mechanics were about retightening to the spec'd torque. It could be that
the one who loctited the bolt also wimped out on the torque, relying on the
loctite to hold the bolt. (Not good practice, but it happens.)

I'm completely undecided on this debate.

Mike

 

I was figuring they were junked cars, so their age and mileage might have
been quite low. One Honda Civic vintage early 1990s I saw in a junkyard last
year had only 5500 miles or so on it. Pretty well stripped, so I figure it
had been there awhile.

Maybe Jim will give the odometer readings next time.

This is a healthy position in which to be, AFAIC.

 

I was figuring they were junked cars, so their age and mileage might have
been quite low. One Honda Civic vintage early 1990s I saw in a junkyard last
year had only 5500 miles or so on it. Pretty well stripped, so I figure it
had been there awhile.

Maybe Jim will give the odometer readings next time.

This is a healthy position in which to be, AFAIC.

 

The difference is, sawblades are not splined or keyed, so they can turn
(and tighten) indefinitely. Splining or keying the pulley WOULD mitigate
this effect.

 

The difference is, sawblades are not splined or keyed, so they can turn
(and tighten) indefinitely. Splining or keying the pulley WOULD mitigate
this effect.

 

ok, let's try this instead:

http://www.flickr.com/photos/38636024@N00/

 

ok, let's try this instead:

http://www.flickr.com/photos/38636024@N00/

 

The pics are here:
http://www.tegger.com/hondafaq/misc/jim-beam_pulley_pics/

Unfortunately, the pics aren't really evidence of much other than this:
You've taken photos of a pulley from an unknown car with an unknown history
given unknown servcicing by persons of unknown competence.


These pics are strongly suggestive of a pulley having been installed at
some point with no Woodruff key, or otherwise installed incorrectly. I can
assure you a pulley properly installed will not gall that way.

A properly tightened joint dowes not rotate. Your pictures do not prove
anythng one way or the other because we do not know the car's history.

 

The pics are here:
http://www.tegger.com/hondafaq/misc/jim-beam_pulley_pics/

Unfortunately, the pics aren't really evidence of much other than this:
You've taken photos of a pulley from an unknown car with an unknown history
given unknown servcicing by persons of unknown competence.


These pics are strongly suggestive of a pulley having been installed at
some point with no Woodruff key, or otherwise installed incorrectly. I can
assure you a pulley properly installed will not gall that way.

A properly tightened joint dowes not rotate. Your pictures do not prove
anythng one way or the other because we do not know the car's history.

 

That's one difference. Also the automotive pulley bolts are to be torqued
to such a figuure as to prevent movement. Your saw blade nuts/bolts are
just snugged by hand to an unknown torque, and are meant to be repeatedly
removed and replaced.

I restate:
"Honda is just about the only manufacturer whose bolts run in a tightening
direction. Everybody else has bolts that run in a LOOSENING direction, and
these DO NOT COME LOOSE IN USE." Nobody can explain why this is, if it's
assumed that the pulley and bolt can move relative to the crank.

And even on a Honda, a pulley bolt insufficiently tightened (as little as
20 lbs short of the proper figure), will eventually result in a bolt that
*FALLS OUT*. Talk to any mechanic familiar with this subject.

The damned assembly is SOLID in use when properly assembled. Nothing
anybody says here will change that fundamental fact.

 

That's one difference. Also the automotive pulley bolts are to be torqued
to such a figuure as to prevent movement. Your saw blade nuts/bolts are
just snugged by hand to an unknown torque, and are meant to be repeatedly
removed and replaced.

I restate:
"Honda is just about the only manufacturer whose bolts run in a tightening
direction. Everybody else has bolts that run in a LOOSENING direction, and
these DO NOT COME LOOSE IN USE." Nobody can explain why this is, if it's
assumed that the pulley and bolt can move relative to the crank.

And even on a Honda, a pulley bolt insufficiently tightened (as little as
20 lbs short of the proper figure), will eventually result in a bolt that
*FALLS OUT*. Talk to any mechanic familiar with this subject.

The damned assembly is SOLID in use when properly assembled. Nothing
anybody says here will change that fundamental fact.

 

I still dunno. I've seen galled steel flat washers and bolt heads various
places before (but I don't recall where they have been), so I wouldn't have
thought it was unusual. I would speculate that the torque we need to apply
to break crank bolts loose isn't being directed to the threads but to the
head, where the galled surfaces are responsible for the excessive
break-loose torque. Pure speculation, though.

Usually crank bolts (Honda or otherwise) need to loosen a quarter turn or so
before they come free, and then there is no evidence of the threads
galling - leading me to the speculation of the galled head and washer
surfaces being the key. That would also be consistent with the observation
that the break-loose torque goes up over the years, if engine heat and/or
vibration is important in the development of the galling.

I don't think we have enough to work with to come up with a definitive
answer.

Mike