balancer bolt again

anlo

Registered User
**** UPDATE **** PICS BELOW !!

well today right on cue about three thousand miles balancer bolt let go again this makes three balancers and four bolts havent got a chance to inspect the balancer for the usual split at the sleeve it may just be the bolt this time i have a year warranty on this balancer anyway.. cant figure why the better mustang bolt would give up time after time .. bought this car with a bad balancer so there is something very weird going on ,,, runs completely true when i replace them all seems great for awhile . its the wifes car when she called today and claimed tach was acting weird then just shut off i knew what it was , got there put my finger on the snout and sure nuff bolt head and washer gone balancer hadnt walked out much this time still looked lined up just a snapped bolt head... wont even look at it till tuesday on the bright side im very good at extracting rest of bolt from snout now.. i may just park it and wait for a bhj and be done with it. but scared the next time the bhj wont give and something else major may happen..... oh well we will see tuesday whats up im just baffled with this issue and had to vent...luckily just bought a 1996 exploder tuesday so the little lady will have to drive that beast.. i realized when i bought the explorer that i just dont want to drive any thing but a supercoupe does anyone else have that issue ? maybe i would take a infinity g35 but thats it...
todd:confused:
 
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runs completely true when i replace them all seems great for awhile

If you are replacing the failed units with another used balancer, it's not unusual that they would fail in only 3000 miles. The aluminum hub conforms to the crank snout when first installed, and never fits as well once removed and reinstalled. The bolt is breaking because the balancer isn't any good. If the bolt didn't fail the crank would break.

The BHJ has a steel hub which is much stronger and it will hold it's shape when removed and reinstalled. If you are still using the factory ~~~ stamped steel pulley, ditch it and get a set of underdrives so the crank pulley will be properly zero balanced.

David
 
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good sense

although 2 of the replacements were new aftermarket and fit snug..
im gonna put the bhj next anyway your comment makes perfect sense dave thanks..
 
balancer bolt update

well removed belts and fan and was able to wiggle balancer off
its still intact however the keyway on the i.d. seems to have enlarged from movement im pretty sure keyway was uniform in size to start with still unsure what would create this condition but it helps my theory about how the fact that key in shaft doesnt continue out the length of snout may contribute to stress precisely at the point where most stock balancers like to shear leaving part of the sleeve on the snout letting outer part of balancer spin freely just a theory but seems plausable . obviously it was designed this way and lots of balancers dont fail but in my case theres something fishy going on with the crank or maybe as dave stated im not at zero balance from the start.. as i stated when installing balancers they seem nicely snug and require effort to slide on so fitment seems fine originally. any one else care to hypothesis on this ordeal ? other than the only logical resort "bhj" im still baffled ???

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Crank pic

hard to see with seal in place but looks like a normal key just too short in my opinion.

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pully front

yes pully still on there are some score marks two together and the otherside one opposite each other on the i.d. away from the keyway that have grooves just like the stretched part of the keyway ..balancer was still aligned in keyway before removing as i had to jiggle it back and forth to pull it off..

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I've put a lot of gears on shafts over the years....

The only way to get that kind cut on a key way is improper alignment when installing hub....
 
if the balancer is able to be moved on and off by hand and just wiggling, you need a new balancer.

this has been stated before.
If a balancer fails, it is almost exclusively due to the fact that it did not fit properly on the crankshaft. The bolt is not a primary retention device. The key way is to prevent the hub from turning due to the excess horsepower the blower pulls off the crank pulley. The main retention device for the balancer on the crank is the use of a interference fit. The balancer should be .001 -.0015 undersized for the crank so that it needs to be pressed onto the crank snout.
 
yes

i can see your point eddie but its almost impossible to mis align that key is a pretty snug fit going on as you twist hub it has to line up right or it wont slide in any further.. are you proposing i missed key way and dug another next to it ? it seems to me over time it just wore itself over making keyway wider which i dont see how unless the metal on the bore is that soft.. the car runs too well for there to be a bind causing it to want to keep twisting within the bore .. i really dont know im just guessing at this time...
had a year warranty on hub but of course cant find reciept oh well it was only $100 bucks but it was aftermarket new.. as i said ill just save up for a bhj and see what happens next.....

it didnt go on without any resistance i had to definately pull it in upon installation very tight fit .. the fitment originally felt correct i was only able to wiggle it off due to the enlarged keyway and snapped bolt allowing it to walk out slightly and there was still some resistance coming off.
 
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it didnt go on without any resistance i had to definately pull it in upon installation very tight fit .. the fitment originally felt correct i was only able to wiggle it off due to the enlarged keyway and snapped bolt allowing it to walk out slightly and there was still some resistance coming off.

pull on to install? You should have to press it on with a tool.
wiggle to remove? you should have to use a balancer puller to remove. It should be nearly if not exactly as difficult to remove and install as the power steering pulley is.
 
yes

yes it pressed on with plenty of interference i broke down and bought the tool after the second balancer figured it would come in handy got tired of renting.. its the official h/b puller/installer tool.i even got the power steering puller as well a very valuable tool indeed
i was only able to wiggle off this time because it had started walking out probably belt kept it on
who knows bolt may have snapped days before the finns got beyond the crank sensor.. probably should have said pressed on... bolt was torqued properly with loctite
 
don't use loc-tite on the balancer bolt. if the bolt breaks, or backs out, it is going to be due to problems with the balancer, most likely a lack of proper interference fit, or worn/damaged elastomer.
 
i can see your point eddie but its almost impossible to mis align that key is a pretty snug fit going on as you twist hub it has to line up right or it wont slide in any further.. are you proposing i missed key way and dug another next to it ? it seems to me over time it just wore itself over making keyway wider which i dont see how unless the metal on the bore is that soft..

Yes, it sure looks like it was slightly off key way when installed....

The soft aluminum of the hub doesn't stand a chance against the hardened steel key....

What happened here was you broached another key way with the key....

If the groove was made because of rotational forces, it would have a more rounded shape with no steps in it.....
 
If the groove was made because of rotational forces, it would have a more rounded shape with no steps in it.....

I agree with Eddie. That really looks like it was forced on. When I install the balancers I rotate until it clicks into the keyway, then I'll lightly tap it until I can get the bolt to grab. Once that's done I use the bolt to pull it in. Then I use a torque wrench to snug it at 132lbs

I take it you won’t need that Water Pump anymore? :rolleyes:
 
well

well the water pump has taken on less priorty as you guessed but i will definately replace it upon other repair as the shaft is slightly bent its not pully ive switched those out to see

after realizing just how soft the i d of the hub is i will have to go with eddies prognosis as well . thanks coug
 
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