to change a Honda Accord 1988 model timing belt

Most Wikis store a version history as well (some indefinitely), so if
someone borks a page, it's easy to revert to the last "good" version.

 

Naaaah, it would clash with my Accord's dark blue.

That's why I noted that some Wikis do support access controls; I've
checked out a few opensource PHP-based ones this afternoon and the most
promising ("Wikka") at least allows administrator locking of individual
pages, or the entire site.

Really, my thinking wasn't to have everyone able to muck with it... it
was more to ease Tegger's workload in updating the site, and making
searching more efficient and effective: most will cross-index things
automatically, so, for example, in the instructions for changing the CV
shafts, you don't have to include the part on how to remove the discs
and hubs and control arms, but instead set those steps up as their own
sub-sections and have the system automatically hot-link to them.

Granted, I don't know how he does it now, if he's using HTML templates
in something like Dreamweaver or FirstPage, or doing it all in Notepad,
or what...

 

Sorry, but this is dead wrong. Once tightened to spec, that bolt does not
move.

It did not rotate to cause this. There are other factors at play here, but
rotation is NOT one of them. This identical same thing happens with Toyotas
and other cars where the engines turns the other way around from Hondas.

The crank pulley has a tiny bit of play even when keyed, but it does not
have nearly enough rotational displacement to ave any significant effect on
torque.

 

You mean FrontPage?

I'm using Mozilla's Composer, which really really sucks, but it's quick and
free.

The interface is from John Ings, the founder. I never liked it (especially
how it looks in Internet Explorer), but in the interests of consistency
until a complete overhaul, I've kept it.

My CSS conversion is being done entirely by hand in Notepad, but I've done
nothing with it since the summer.
http://www.tegger.com/honda-css/
(Only the first three work. Sort of)

I've actually got the CSS stuff up on screen right now, with grand
intentions of reviving it, but...

 

That's the missing link. Now I understand.

I understand and did not mean to accuse you of the same. I just figured I
was missing something and would have to go read up on the minutiae how
Wikipedia works. No way could the main Wikipedia entries be so "clean"
without some kind of controls.

I follow. Not to push Tegger around or anything, though. I've been using his
igniter section (partly to parse all that condenser ( = capacitor) stuff Jim
Beam's posting and see the layering and treeing etc. is getting tricky. It's
still very user friendly, but I can kinda see how the editor/owner of such a
site has to do a lot of work to keep it up. (I wouldn't do any better.)

Notepad. I remember those days. (Though it's not like I'm cussing any less
using Earthlink's web site builder. I still get to the source code through a
convenient back door it provides and make any doggone changes I want.)

 

dude, it can and it does. that's why drive shaft nuts are peened - same
thing. one will tighten, the other loosen. the amount of movement is
restricted to the lash on each side of the key, but it doesn't even need
a thou to slowly rotate. just because it doesn't /look/ like it's
moving, doesn't mean it won't!

again, untrue. q: how much rotation is attributable to each hammer blow
in a pneumatic impact driver a: not much! it's the extremely high blow
count that gets it moving and then the turbine can take over the job of
winding the nut/bolt off.

 

Nope. FirstPage2000, from www.evrsoft.com. It's a freeware HTML
editor, basically a clone of another commercial package that I've
forgotten the name of (Macromedia bought out the commercial one and
bundled it with StudioMX).

Fr*ntpage is a filthy word, as far as I'm concerned...

Hmmm... I know a lot of PHP CMS (content management system) backends use
CSS... an appropriately-equipped Wiki probably would as well.

I can toss a couple up on my webserver if you want to take a look at the
idea. If not, no biggie, was just a thought

 

Do you havre any references to this?

Then explain why the exact same thing happens to Toyotas, Fords and other
vehicles that turn the engine such as to LOOSEN the bolt.

I have been unable to find any references to your alleged phenomenon in
Google searches.


My personal theory is that with heat and vibration, the bolt and its
threads "settle in" and thus increase their static friction.

 

bolts can loosen on side loads - as is the case with l/h wheel nuts on
cars where r/h threads are used. or they can tighten - as is the case
with pedal spindles on bikes. bikes have r/h thread on the right and
l/h thread on the left to prevent loosening, and often these continue to
tighten with use. side loads cause what's called "precession" and that
works both ways.

we don't have much side load here, so the only movement is angular. an
example of angular tightening is the locking ring on a fixed gear bike.
it's l/h thread vs. the drive cog which is normal r/h thread. the
drive cog can move back & forth slightly in use [resistive braking] and
this tightens the locking ring. in fact, because soft alloy hubs are
used, it's not uncommon for the locking ring to strip after a time, even
though the initial tightening torque of the cog & ring are well within
normal spec.

regarding citations for the honda pulley bolt, i don't have anything
immediately to hand. you have to go back to basic engineering
principles. if you can accept that there is some angular lash in the
pulley, you can figure out the inertial predominance of that lash as the
crank rotates.

i absolutely agree, other factors such as rust do undoubtedly have a
significant impact on tightness of fasteners, but that's not the case
with my crx and messing about with the pulley bolt on two seperate
disassemblies on consecutive days with only one run in between.
[initially to replace the locked water pump and determine whether the
motor worked at all, and the second day, having decided that the motor
ran like a champ, deciding to re-do the job properly and put in a new
pump, not the junker i'd used before.]

i'll also say that having worked on a number of other "right way" motors
and loosened their pulley bolts as well, i've never come across anything
as tight as the honda bolt. the difficulty with an ordinary pulley bolt
is simply holding the wheel so the bolt can be undone. once the pulley
wheel is held, it's not that much of a problem. and you'll note that
most of them have locking washers under them [the honda doesn't]. the
starter motor trick is a great quick convenience if you don't want to
bother with a holding tool or have an impact driver. but even if the
motor turned the right way for the starter motor to try unscrewing this
bolt, i'm not sure it would work in this case. starter motor cranking
torque i believe to be in the range ~200 ft.lbs, [which /would/ shift an
unstuck bolt] but i think estimates of these honda bolts being stuck at
over 400 ft.lbs completely reasonable based on me needing to bounce my
full weight on an 18" [3/4"] breaker bar.

 

Wow the replies are overwhelming. Thanks Dudes... Its like bing in Honda
knowledge heaven..

 

It's still wrong. That bolt does NOT turn.

Honda is very particular about the treatment of this critical fastener.
They specify that oil be applied to the /threads/, but not to the /bolt
face or washer/. Not only that, but they also specify that if a new
fastener is used, it should be pre-stretched to a higher-than-final-torque
before being loosened and final-torqued to the lower number.

If the bolt could tighten and stretch itself some unknown amount, do you
really think Honda would risk such an unknown variable in such a critical
area? What if the bolt tightened too much? Disaster!

And if that final higher torque /were/ predictable, don't you think Honda
would specify that final torque to begin with, and simply tell you to set
it to that in order to eliminate that variable?

Also, if you look at bolt torque charts, there is NO bolt of that size, not
even an aircraft-grade M10.9, that is intended to be torqued to anywhere
close to the 300 ft lbs that Elle guesses at.
The highest rating I can find in my charts is for a 12mm 11T with 1.25mm
pitch. It's rating is...130 ft lbs, exactly what Honda specifies for the
crank bolt, which I'm pretty sure is that size!

In areas where Honda suspects torque change may occur, it specifies
staking, lockwashers, bent tabs, and nylon inserts. But not at the crank
bolt.

Incidentally, our Toyota Tercel's engine runs so as to LOOSEN the crank
bolt. The bolt is tightened to 114 ft lbs. There is no lockwasher.

And as far as relative movement due to inertia? Consider this: The bolt is
less than one pound. The combined reciprocating and rotating mass of the
engine is about 50 lbs. It is physically /impossible/, even considering
firing pulses, for a 50lb mass to accelerate faster than a one-pound mass
given the same impulses to both.

Even considering the frictional resistance of the PS pump, A/C compressor,
and alternator, there is no way all that exceeds the inertial mass of the
engine. It is physically /impossible/ for the crank to force the bolt to
tighten.

It is true that there are certain circumstances where a fastener can be
forced to tighten or loosen even when tightened properly, such as knock-off
wheels. In that case, the weight of the entire car is pulling and pushing
the fastener around. That, combined with splines that are a less-than
perfect fit, and wheel flex, means the wheel's knockoff nut is subject to
unique stresses that a crankshaft bolt is not.

The relevant paragraph on Elle's page is totally wrong and needs to be
removed.

 

so how does an impact driver work then?

 

This may be prudent, but it's not important enough to be mentioned in all
the UK site manuals.

I suspect the concern is to prevent dripping oil (from the washer and bolt
faces) onto the other drive belts.

It's not "unknown." The bolt can only heat so much. The crankshaft can only
have so much horsepower applied to it, and so forth.

The torque on the pulley bolt isn't just going to keep going up and up as
the years and miles on the car pass.

The bolt at the UK site's manuals is referred to as the "special bolt." I
don't think that's just to be cute. I don't know if it's grade 10.9,
something that you or I could buy in a hardware store (at no small cost
compared to lower strength bolt materials) and is designated for many
automotive uses. I suspect it's 12.9.

No, because it's not a variable without limit.

So you reject the many posts to this newsgroup stating that greater than 300
ft-lb rated air wrenches would not break the bolt free? These people all
were using wrenches whose rating was far less than what was advertised for
the tool?

You disbelieve the folks who estimate the force they use to break it free,
using their body weight at a distance of X from the centerline of the bolt?

Are you aware that factors of safety are a part of the design process? This
should be particularly obvious to you if you are aware that, even using a
torque wrench and following directions for torquing, cleaning the threads in
advance, etc., the actual tensile load applied to a bolt can vary greatly
for a given setting on the torque wrench.

It's cold hard fact that people who work on cars routinely apply over 300
ft-lbs of torque to these bolts, and the heads do not shear off. I suspect
this is due to the design factor of safety being quite large, or else they
use a higher strength material, even stronger than grade 10.9. I'd have to
investigate further.

Your claim that the problem is rust is at least as much a guess.

From the manuals:

1984-87 Civic: 12 mm diameter, 1.25 pitch, spec 83 ft-lbs
1988-91 Civic: 14 mm diameter/1.25 pitch, spec 119 ft-lbs
1992-95 Civic: 14/1.25, spec 134 ft-lbs

1990 Accord: 14/1.25 spec 166 ft-lbs
1991-93 Accord: 14/1.25 spec 159 ft-lbs
1994-95 Accord: 16 mm, spec 181 ft-lbs

It's a 16 mm bolt for many of the more recent Hondas as well.

Only the crankshaft and pulley (which is keyed to the crankshaft) get the
impulse.

The bolt gets the "impulse" /in/directly.

It's like putting a 1 foot square, 3/8-inch thick wood board on the roof of
one's car and then accelerating the car. The board flies off. Why? Because
it's not fastened to the car roof, and because the coefficient of friction
and board's weight are too small to cause the board to move with the car.

This is why one can screw the bolt into place with the crankshaft/pulley
fixed.

Of course, there is an important difference once the pulley/crankshaft/bolt
assembly is running at normal operating temperatures: The bolt heats up, and
the geometries are such that it could very well loosen as it heats.

It's like initially super-gluing the board to the top of one's car roof,
then slowly dissolving the glue. The board slowly loosens, and the car
starts to move at a different speed from the board, even though just moments
ago, when the board was glued to the car, they moved at the same speed.

 

By delivering many heavy, but short-duration blows in rapid succession.

With its internal gearing having been specifically designed for this, the
driver's mechanism is capable of rapid acceleration. However, you need a
certain amount of air volume being delivered at a certain speed, otherwise
the impact driver's internals cannot spin up properly and will be unable to
deliver the proper blows. Hook the driver up to a low-volume compressor and
you'll see what I mean. You'll be able to hold the chuck still with your
hand as you pull the trigger.

Also, the driver is trying to move ONLY the bolt. If the /engine/ tries to
move the bolt, it's working at a mechanical disadvantage, being much
heavier, and being unable to accelerate as fast as would be required. The
bolt has then plenty of time to leisurely spin up with the engine.

If you use an impact driver to loosen the bolt, you'll find that the
crankshaft moves not at all. This is because the engine has too much
inertia, and it would require the impact driver's blows to be of MUCH
longer duration in order to overcome the inertia, and at that point it
would twist right out of your hands.

 

Where the joint was designed for a lubricated fastener, it is /very/
important.

The oil is there so the friction coefficient will be more constant. You
don't dump a gallon of oil on the threads, you just put a few dabs on them.

The problem is that the bolt's own thread friction can dramatically affect
torque. Honda is controlling that as best it can. The threads, and the
specified torque, have been calculated with a lubricated fastener, not a
dry one.

It is possible that crank bolts used in situations where oil is not
required are already plated with a friction-modifying coating, such as
cadmium.

The why wouldn't Honda just specify the final torque to begin with? Your
statements make no sense. There is NO fastener on the car that is asked to
stretch to a new torque figure AFTER final user torqe has been applied by
the user. NONE. Not even connecting rod bolts, which undergo the highest
stresses of ANY bolt on ANY car.

There was no such thing when Honda built my car or yours. 11.9 was the
highest Metric bolt strength went. 10.9 is /not/ something you can buy at a
corner hardware store. It's equivalent to SAE Grade-8. That is, aircraft
grade.

Of course not. As I stated before, it is common knowledge that the force
needed to overcome /static/ friction is far greater than the original
tightening torque. Add corrosion to that, and you've got yourself a real
pickle.

Not all bolts get that tight, either. Mine (originally tightened to 130 ft
lbs) came loose easily with a 250lb electric impact gun.

And you cannot use your theory to explain why crank bolts are equally as
hard to undo on engines that run so as to LOOSEN the crank bolt, which is
pretty much all engines other than Hondas.


<snip>


Your assertion is wrong, Elle. Completely and utterly. That bolt does NOT
turn after final torquing. It cannot and it does not.

I'm adding a paragraph to my link to your page to warn people of your
misinformation.

 

Because the bolt is /not heated/ when a technician or DIYer applies that
final torque.

Again, many large bolts (I'm talking over an inch in diameter) are routinely
torqued into place not with a torque wrench; not with slug wrenches (which
may be a new type of wrench to you, but anyway); but instead by first hand
tightening the bolt, then inserting an electric heater into a hole drilled
in its center. The temperature of the bolt rises, the coefficient of thermal
expansion works as designed, the bolt gets longer but the diameter gets
smaller. The bolt is screwed in X # of turns further, then the heater is
removed. Guess what happens?

If you're a relative layperson to certain engineering topics, then they'll
be hard to digest on the first go-around.

What I think you're missing is that the alternative is to put the bolt on so
that the rotation of the engine loosened it. And that I believe the engine
would, all else being equal, on these Hondas.

Now that's enough. Soon I will post photos at my site showing the two grade
8 bolts that my pulley holder tool uses, including the six marks on the top
that show them to be Grade 8. I bought these at my corner hardware store,
which happens to be True Value. And they were expensive, as far as bolts go,
as one might expect.

You don't know that these bolts are not special order.

If you loosen it regularly, this wouldn't surprise me.

Jim says otherwise.

Funny how you didn't address my points re the key connecting the pulley and
shaft, but not the pulley/shaft and bolt.

I think the thread speaks for itself at this point.

If you are going to deride my site beyond saying you have a different
opinion on the manner in which the bolt becomes so tight, then I think it
would be best if you didn't link my page to yours. Because you're just
reproducing Usenet drivel by deriding my position.

OTOH, since the goal is to help DIYers etc., if you want to redo the
information that is at my page and present it as your own, I will take no
offense.

I said I wouldn't criticize further unless I came up with an alternative. I
think I've kept up my end of the deal. You are of course free to reject my
alternative.

 

Sorry to jump in, but if you heat something, it gets bigger in all
directions. Think about how a ring gear would fit to a flywheel, you
heat it and it gets bigger so it will drop on, it does NOT just get
wider (as opposed to bigger diameter) which is the implication of what
you are saying. Heat a bolt and it gets bigger.

However if it's a long bolt the percentage expansion will be the same in
all directions, but the actual length change in inches (or mm) will be
greater along the long axis. So when it cools the shrinkage is more
along its length - as an amount NOT as a percentage. So of course the
axial load will increase.

Torque is not what the designer wants, he/she wants axial load. This is
virtually impossible to measure & control in a manufacturing situation,
hence the need to correlate axial load against torque, and therefore to
control torque.

 

Make this "long enough," for the sake of a bit more precision in this
discussion.

axial load in

With the change above, agreed.

For the record I do not assert my theory as fact. It's my personal best
guess as to why the pulley bolt becomes so tight. I do not now intend to
qualify the statement at the site, because I think what's written at the
many personal web sites on Honda repairs by their nature imply that they are
only the author's opinion.

Also, to clarify, when I wrote, "You don't know that these bolts are not
special order," I meant the crankshaft pulley bolts. Honda may very well
special order these bolts from a specialized bolt manufacturer.

Grade 8 bolts at my local True Value are in bins accessible to all customers
and are not special order.

If I can quickly figure out the new camera I bought this morning, I'll throw
some photos up at the site, FWIW.

 

Uh-oh. An attempt at getting the upper hand by using jargon and an
ad-hominem attack. Bad sign.

I just looked up "slug wrench". It's just an industrial wrench with one
closed-end, like half an ordinary combination wrench. Big deal. How is that
relevant to this discussion?



but

Sure. Since the BOLT is heated, but not its receiving piece, you get
additional torque. It's called "heat tightening". If you heated both halves
equally, this would not work. But even that does not involve tightening
AFTER the final torque figure is achieved by the install procedure.

Also, There are no such bolts on Hondas.

Your misunderstanding of the reason for oil on the threads does not say
much for your engineeering knowledge either.

That describes most other engines on the road! You've never tried to remove
a pulley bolt on one of those, that's clear.

Yeah, but can you buy them /loose/ at True Value? I'm not gonna buy a
pulley holder just so can get the bolts from it.

Home Depot and places like that go up to SAE Grade-3 on loose bolts.

I don't. Just for the timing belt.

I say other-otherwise.

What? Better rephrase that one.

I am not "deriding" it, I am /refuting/ it. And refuting it by offering
reasons for my disagreement.

You, on the other hand, are calling me ignorant (the slug wrench thing),
and are accusing me of things I haven't done.

Why would I do that?

I haven't. I've just rejected the assertion that there exists a non-
existent phenomenon. Everything else was fine, as I stated.

 

But this has absolutely NOTHING to do with additional tightening after the
final setting!

So far, /nobody/ has been able to cite references that mention this alleged
additional rotational displacement of a bolt after final tightening, and I
have been unable to find any references in Google.

Here's two good pages:
http://www.boltscience.com/pages/tighten.htm
http://www.boltscience.com/pages/info.htm
Note there is no mention whatsoever of the alleged phenomenon.

Honda does not make ANY bolts. ALL of them are purchased from outside
suppliers.

Well then maybe it's just Canada. The local Home Depot only has up to
Grade-3. If I want anything higher, I need to go to a specialized fastener
place.