Chipped Crankshaft Pulley

97 accord v6 I snapped 5-6 craftsman 1/2 drive extensions and several sockets
trying to remove my cranshaft pulley bolt. I nearly killed myself ;-) when the
extensions twisted, loaded up like a tortion bar, and shattered into several
pieces, or the socket cracked.
I didnt have any luck removing the bolt untill I used an impact wrench, impact
extension, and impact socket, and a very short lenght of 3/8" air hose (130psi at
the compressor).

what didnt work was when I had 50' of 3/8 air hose, I think I was only getting
60-80 psi at the gun. the shorter the hose the more pressure at the gun.

 

i saw that. all that really matters is shear modulus [not to be
confused with shear strength], and most steels are very similar.
matweb.com [iirc] has a good searchable properties section.

hmm. if you're using a jack as a pivot, you're already into "unsafe
workshop practice" territory. and a 5' pipe extension requires only
~24lbs of you to reach manufacturer spec of 120ft.lbs so it's massive
overkill. with you being behind an unspecified number of extension
inches, /&/ 5' off axis, you have no control over the business end of
this tool. remember, it needs to remain snug on the nut throughout this
operation so there really should be a component of axial pressure to
keep the tool in place as well as the unscrewing torque. if you don't
feel big or strong enough to handle this without abnormal tools, then
find an appropriately sized assistant or get an impact wrench. i know
that "i can do this on my own thanks" seems to be an issue for some of
you mechanic chicks. get over it. size matters. and size /= gender.

well, think of it like this. if you're trying to apply 1lb of force
with a 1lb spring and 1lb of force with a 100lb spring, the 100lb spring
is going to have less bounce and make uneven movement much less of an
issue than the 1lb spring. just like if you've ever noticed how hard it
is to weigh stuff on grandma's old kitchen scales when it's getting to
the end of the gauge - the needle wobbles about all over the place.
same with long extensions. you have a much weaker "spring" than short
ones because, for the same material & diameter, the springiness is a
function of length. the math for this is on the web. you are correct
that the same torque is transmitted by both long & short extensions, but
accurate torque is about control, and that's not something you have a
lot of the way you have proposed.

yes, adaptor at the business end.

 

The '95 uses the the immobilizing tool that looks like a big nut with a hole
in the middle and a flange on the side for a breaker bar. They cost about
$50 on the web. 1/2 inch sockets and extensions will work fine, as long as
you make sure they are all case hardened (impact sockets and hardened
extension & breaker bar.)

400 ft-lbs probably won't do it. We estimated the breaking torque on the
'95 Odyssey (same big four that the accord uses) was somewhere around 500+
ft-lbs. With the 4 foot gas pipe on the breaker bar it wasn't all that bad,
one man could easily generate enough force to pop it. You just need to be
careful and stick to a short extension or none at all to minimize the
twisting.

 

re using extensions to free the crankshaft pulley bolt--

www.matweb.com is great.

Today I realized I, among others here, have a pretty good "laboratory estimate"
already of the twist in the extensions. Last week when I broke my pulley bolt
free, I recall having to rotate the extension bar around 90 degrees (= 1/4
revolution) before the bolt broke loose. That's a very crude estimate done
before I did the calculation below. It wasn't 180 degrees. It wasn't 10 degrees.

The rotation of a bar under torsion is given by Theta, radians = TL/JG

With
T = 500 ft-lbs
L = 25 inches (two ten-inch extensions + long socket, etc.)
J = polar second moment of area of a 1/2-inch drive
G = 11,300 psi

This yields about 75 degrees of rotation.

The guy named "M" posted here today that he broke a number of Craftsman 1/2-inch
extensions and sockets when trying to remove the pulley bolt on his 97 Honda
V-6. This is instructive and helpful for people to know. But one of the sites
(http://www.cadvision.com/blanchas/54pontiac/honda.html ) I routinely quote here
talks about breaking three cheap extensions while trying to free the pulley
bolt. So I for one knew what to look for. Also, to my "credit," over the years I
have sheared at least one socket and now two 3/8"-1/4" adapters. I do not go at
this lightly. No one should.

I do suspect the required torque for the V-6 engine's pulley bolt is higher than
my in-line 1.5L four cylinder engine. Still, M's post is important. The
inexperienced should take special note.

The car's jack is way overkill for supporting the load here. It's more unsafe to
change one's tire with these jacks.

With the 5' extension I was breaking the bolt free, not tightening it. As has
been reported here, some folks estimate around 500 ft-lbs. or torque are needed.

I estimate I needed over 300 ft-lbs. of torque to break mine free last week.

When installing the bolt, I used a 1-foot pipe extension and my weight for the
manual-required 119 ft-lbs of torque.

I have as much control over it as someone pulling with both hands from above the
car or someone using a high-powered torque wrench.

You're forgetting that the final snugging involves rotation of maybe 1/4 turn.
The bolt advances at most 1/4 turn. If you do this in five steps, pushing on the
socket each time, I don't consider this anymore or less safe than any other
method.

My car's pulley bolt is already broken free, Jim. I described my technique. If
you want to upbraid my approach, I expect you to upbraid just about every person
here who posts their technique. None of them are particularly more or less safe
than what I did, from my reading.

I have serious experience with major machinery. I have been the lead mechanical
engineer for a Fortune 500 company on a mega-million bucks nuclear power plant
component replacement job. The most important bolts for this job had to be
torqued so highly that special heating elements were used to stretch them, so
they could easily be screwed in. Upon cooling, the torque built up. I have also
watched bolts being torqued using hydraulic pressure. I have significant other
experience (years) with major power plant components. I know what kind of forces
are involved here.

I also often run the stress and other, related numbers, as I alluded before, to
see that I have some safety margin. Most male mechanics I know wing it.

Men are far less safety conscious than women, on average, from my observations.
So, yes, Jim, get over it: Mere size is not enough to keep a person safe. A lot
of men delude themselves into thinking they can do anything.

Just consider the number of yahoos posting here about their pride in driving 90
mph in their ordinary Honda down the freeway.

snip

No, accurate torque is about using a calibrated torque wrench or a calibrated
weight at the end of a known torque arm distance.

The angular twist in the extensions while torquing down the pulley bolt is
completely irrelevant to what the torque wrench senses. One gets the 'click' (on
the usual torque wrench), or one does not. If one is very concerned, torque in
five or so steps.

 

dude, please don't think i'm knocking you - i'm not, so please be less
defensive. i don't doubt your experience, but, with respect, i've been
around the block a couple of times as well.

regarding supporting a wrench with a jack, of course the jack can take
the load - that's not the point. the point is, even with the best
intent, the wrench is not under full control in that situation so it's
potentially very dangerous in the event of slippage or breakage.
period. a large person with two hands on the tool [regardless of
gender] - one on the end of the lever and the other on the pivot /is/ a
properly controlled situation - as is a pneumatic impact drive.

regarding torque application, again, you are correct that torque at one
end = torque at the other, /but/ you're not allowing for the dynamic
affects of wind-up. you know how you can hold a pneumatic impact wrench
in one hand and have it hammer off 400ft.lbs? ever wondered why it
doesn't break your arm off? that's dynamic loading - it depends on the
very short duration impact momentum of the hammer striking its anvil to
do the work, not any force that can be applied by your arm. and to
limit the torque applied by impact wrenches, you can get extension bars
like this:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42478

do the math for a reduced diameter extension bar like one of these, then
compare it to one with extended length. notice the correlation?

in a situation where you do not have a smooth bolt rotation, the
action/sprung reaction effect of a long extension /can/ affect accurate
torque application. it's not simply a "weight at the end of a beam" but
also the time over which that weight is applied - and time is affected
by the spring rate.

best

jb

 

The JB Weld held fine for I figure about two weeks. But yesterday I discovered
the chipped off piece had come free. It's now lost forever. Must have
miscalculated for "worst case" scenarios--hitting bumps, etc.

Worse, as George supposed, the power steering belt does look a bit frayed on the
edge closest to the chipped section.

My first local salvage yard didn't have the right pulley, after all. The second
local salvage yard wanted almost the same as Majestic online (about $100) for a
used pulley. This despite my "fierce negotiations." The guy at the yard kept
insisting he could get $100 for it from local shops. I told him I'd keep
thinking about it but walked out happily, feeling pretty confident I could do
better online, one way or another. Meanwhile I drive prepared to lose power
steering...

Ebay occasionally has non-performance (i.e. OEM non aluminum) pulleys for early
1990s Hondas but not right now. I researched on the net and discovered the
online salvage yard business. Pretty cool. Many (most?) have search engines
which all seem to use the same format. Dunno what's with this but the responses
I got varied enough for me to think I was pretty much searching one store's
inventory at a time.

I found one pulley (and I mean exactly one!) that should work on my car.
Interchangeability is very limited, with IIRC variation in pulley wheel
diameters for the alternator and PS belts (didn't check power steering). Plus,
not all of them had the correct circumferential holes for which my home-made
pulley holder tool is designed, so, you know... ;-)

By the looks of things at the Majestic site, only 1989-91 Civic LX (and only
LX!) pulleys are identical.

I'm paying $50 total (= part cost + shipping/handling) to Olstons.com for a 1990
LX pulley, with the clerk there double checking two diameters for me, shipped
UPS. Hopefully it's a fit.

Meanwhile I'm finding other uses for JB Weld around the house.

 

The JB Weld held fine for I figure about two weeks. But yesterday I discovered
the chipped off piece had come free. It's now lost forever. Must have
miscalculated for "worst case" scenarios--hitting bumps, etc.

Worse, as George supposed, the power steering belt does look a bit frayed on the
edge closest to the chipped section.

My first local salvage yard didn't have the right pulley, after all. The second
local salvage yard wanted almost the same as Majestic online (about $100) for a
used pulley. This despite my "fierce negotiations." The guy at the yard kept
insisting he could get $100 for it from local shops. I told him I'd keep
thinking about it but walked out happily, feeling pretty confident I could do
better online, one way or another. Meanwhile I drive prepared to lose power
steering...

Ebay occasionally has non-performance (i.e. OEM non aluminum) pulleys for early
1990s Hondas but not right now. I researched on the net and discovered the
online salvage yard business. Pretty cool. Many (most?) have search engines
which all seem to use the same format. Dunno what's with this but the responses
I got varied enough for me to think I was pretty much searching one store's
inventory at a time.

I found one pulley (and I mean exactly one!) that should work on my car.
Interchangeability is very limited, with IIRC variation in pulley wheel
diameters for the alternator and PS belts (didn't check power steering). Plus,
not all of them had the correct circumferential holes for which my home-made
pulley holder tool is designed, so, you know... ;-)

By the looks of things at the Majestic site, only 1989-91 Civic LX (and only
LX!) pulleys are identical.

I'm paying $50 total (= part cost + shipping/handling) to Olstons.com for a 1990
LX pulley, with the clerk there double checking two diameters for me, shipped
UPS. Hopefully it's a fit.

Meanwhile I'm finding other uses for JB Weld around the house.

 

im wondering whether the sharp edge where the pulley broke can be filed
or ground down to make it "softer" as a stopgap measure.

 

im wondering whether the sharp edge where the pulley broke can be filed
or ground down to make it "softer" as a stopgap measure.

 

Yes, I am thinking about doing this, as I monitor the PS belt's fraying. ;-)
Only a few inches of one edge seem to be staying frayed, with no worsening.
Maybe the fraying occurred when the JB weld gave up and the chip flew off.

Maybe I'll lay a little JB weld on there to smooth out the rough edges, too.

Anyway, I'm not sweating it. My "new" pulley should be here within a week, and I
don't need the car for anything but recreation lately.

 

Yes, I am thinking about doing this, as I monitor the PS belt's fraying. ;-)
Only a few inches of one edge seem to be staying frayed, with no worsening.
Maybe the fraying occurred when the JB weld gave up and the chip flew off.

Maybe I'll lay a little JB weld on there to smooth out the rough edges, too.

Anyway, I'm not sweating it. My "new" pulley should be here within a week, and I
don't need the car for anything but recreation lately.