crank bolt right or left hand thread?

Just bought a used zHonda and am installing timing belt
righ or left hand thread?


Thanks


SW

Right hand thread.

The crankshaft pulley bolt is typically extremely tight.

See discussion at
http://home.earthlink.net/~honda.lioness/id6.html
and
http://www.tegger.com/hondafaq/cranktool/index.html


"swhaley" <swhaley@xxxnc.rr.com> wrote
> Just bought a used zHonda and am installing timing belt
> righ or left hand thread?

"Elle" <honda.lioness@nospam.earthlink.net> wrote in message
news:iLXrg.4938$PE1.4853@newsread2.news.pas.earthl ink.net...
> Right hand thread.
>
> The crankshaft pulley bolt is typically extremely tight.
>
We never did do a test to determine whether the bolt is actually tightening
over time or whether the bond is just strengthening, did we? All everybody
agrees on is that it is a devil to get loose, at least for the first timing
belt change.

Mike

"Michael Pardee" <michaeltnull@cybertrails.com> wrote
> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>> Right hand thread.
>>
>> The crankshaft pulley bolt is typically extremely tight.
>>
> We never did do a test to determine whether the bolt is
> actually tightening over time or whether the bond is just
> strengthening, did we?

You wouldn't want this group to be boring, would you? ;-)

I am not sure a test exists that would persuade everyone or
persuade effectively.

I wasn't willing to perform tests on my 91 Civic's.

I am convinced that the fact that it's not merely a fine
thread but a super fine thread means the bond becomes
stronger over time, especially when subject to heat cycling.
Bolt metal melds into the metal of the crankshaft. I
certainly think it's possible that this is all that's
causing it to become so difficult to break loose. I won't
hold my breath, but we might all agree on this point.

Having conquered (well, with a lot of group support) eight
frozen, fine thread, suspension bolts, and noticing that at
least one appeared to be welded to the inner sleeve (and had
to be completely cut out with an air die grinder), I can
believe that the pulley bolt sees similar forces and so
similarly becomes "more tightly bonded" as time goes on.

The contravening evidence is J. Beam's claim that the pulley
bolt becomes extremely tight again after just a very short
time driving (like less than a day, IIRC).

>All everybody agrees on is that it is a devil to get loose,
>at least for the first timing belt change.

After two timing belt changes, mine still required over
about 300 ft-lbs, by my calculations.

"Elle" <honda.lioness@nospam.earthlink.net> wrote in message
news:3dYrg.2021$vO.1051@newsread4.news.pas.earthli nk.net...
> "Michael Pardee" <michaeltnull@cybertrails.com> wrote
>> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>>> Right hand thread.
>>>
>>> The crankshaft pulley bolt is typically extremely tight.
>>>
>> We never did do a test to determine whether the bolt is actually
>> tightening over time or whether the bond is just strengthening, did we?
>
> You wouldn't want this group to be boring, would you? ;-)
>
> I am not sure a test exists that would persuade everyone or persuade
> effectively.
>
> I wasn't willing to perform tests on my 91 Civic's.
>
> I am convinced that the fact that it's not merely a fine thread but a
> super fine thread means the bond becomes stronger over time, especially
> when subject to heat cycling. Bolt metal melds into the metal of the
> crankshaft. I certainly think it's possible that this is all that's
> causing it to become so difficult to break loose. I won't hold my breath,
> but we might all agree on this point.
>
> Having conquered (well, with a lot of group support) eight frozen, fine
> thread, suspension bolts, and noticing that at least one appeared to be
> welded to the inner sleeve (and had to be completely cut out with an air
> die grinder), I can believe that the pulley bolt sees similar forces and
> so similarly becomes "more tightly bonded" as time goes on.
>
> The contravening evidence is J. Beam's claim that the pulley bolt becomes
> extremely tight again after just a very short time driving (like less than
> a day, IIRC).
>
>>All everybody agrees on is that it is a devil to get loose, at least for
>>the first timing belt change.
>
> After two timing belt changes, mine still required over about 300 ft-lbs,
> by my calculations.
>
I absolve you of the burden ;-)

I just recalled that you suggested a spot of nail polish to match-mark the
bolt head and pulley, and I'm fresh out of nail polish.

All that aside, I agree that it is probably a cold-weld process that makes
the break-away torque so high. People have also reported that working both
in the loosen and tighten directions with an impact gun helps, which
supports that theory.

Mike

"Michael Pardee" <michaeltnull@cybertrails.com> wrote

> I just recalled that you suggested a spot of nail polish
> to match-mark the bolt head and pulley, and I'm fresh out
> of nail polish.

Oh right you are. I do a timing belt change next summer and
might try this then.

I figure that bolt is good for only so many cycles of
tightening and loosening by hand.

> All that aside, I agree that it is probably a cold-weld
> process that makes the break-away torque so high. People
> have also reported that working both in the loosen and
> tighten directions with an impact gun helps, which
> supports that theory.

I'll think about that. Seems reasonable enough. :-)

"Michael Pardee" <michaeltnull@cybertrails.com> wrote in
newsa2dneT-Eoy11C3ZnZ2dnUVZ_uqdnZ2d@sedona.net:

> "Elle" <honda.lioness@nospam.earthlink.net> wrote in message
> news:iLXrg.4938$PE1.4853@newsread2.news.pas.earthl ink.net...
>> Right hand thread.
>>
>> The crankshaft pulley bolt is typically extremely tight.
>>
> We never did do a test to determine whether the bolt is actually
> tightening over time or whether the bond is just strengthening, did
> we? All everybody agrees on is that it is a devil to get loose, at
> least for the first timing belt change.
>



I had an email conversation I had with an engineer at
www.boltscience.com .

He said the bolt is not rotating. Period. There are several other well-
established mechanical reasons for the apparent increase in torque over
time. Rotation after the final installation setting is **NOT** one of them.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"TeGGeRï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï ¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½" wrote:
> "Michael Pardee" <michaeltnull@cybertrails.com> wrote in
> newsa2dneT-Eoy11C3ZnZ2dnUVZ_uqdnZ2d@sedona.net:
>
>
>>"Elle" <honda.lioness@nospam.earthlink.net> wrote in message
>>news:iLXrg.4938$PE1.4853@newsread2.news.pas.eart hlink.net...
>>
>>>Right hand thread.
>>>
>>>The crankshaft pulley bolt is typically extremely tight.
>>>
>>
>>We never did do a test to determine whether the bolt is actually
>>tightening over time or whether the bond is just strengthening, did
>>we? All everybody agrees on is that it is a devil to get loose, at
>>least for the first timing belt change.
>>
>
>
>
>
> I had an email conversation I had with an engineer at
> www.boltscience.com .
>
> He said the bolt is not rotating. Period. There are several other well-
> established mechanical reasons for the apparent increase in torque over
> time. Rotation after the final installation setting is **NOT** one of them.
>
with respect, the pics i showed definitely /do/ evidence rotation.
there's angular galling on the washer/bolt interface. that simply
cannot happen if it's static. besides, bolt precession is well known.
much more attention is given to loosening since that tends to be
catastrophic, but tightening happens as well.

you can do this experiment at home: loosen the pedals on a bike so
they're only finger tight. now, pedal around the block. you'll find
you need a wrench to get them undone again. that's precession that
tightens. and it's why left hand pedals have a left hand thread.

"TeGGeR®" <tegger@tegger.c0m> wrote
> "Michael Pardee" <michaeltnull@cybertrails.com> wrote
>> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>>> Right hand thread.
>>>
>>> The crankshaft pulley bolt is typically extremely tight.
>>>
>> We never did do a test to determine whether the bolt is
>> actually
>> tightening over time or whether the bond is just
>> strengthening, did
>> we? All everybody agrees on is that it is a devil to get
>> loose, at
>> least for the first timing belt change.
>>
>
>
>
> I had an email conversation I had with an engineer at
> www.boltscience.com .
>
> He said the bolt is not rotating. Period.

Be fair. You shared the message with me. He said it was
unlikely, or words to that effect. That's his opinion.

He also did not offer any particularly compelling
alternative explanation.

"jim beam" <nospam@example.net> wrote in message
news:f-adnZ-O0NVJKSzZnZ2dnUVZ_uudnZ2d@speakeasy.net...
>
> you can do this experiment at home: loosen the pedals on a bike so
> they're only finger tight. now, pedal around the block. you'll find you
> need a wrench to get them undone again. that's precession that tightens.
> and it's why left hand pedals have a left hand thread.

That's a very different physical arrangement, though. The friction of the
bearings, small as it may be, works to screw the pedals in - as you point
out, that's why the left hand thread on left side pedals. There is no
equivalent force on the crank bolt.

Mike