nmbsun

In two years I have had 3 Harmonic Balancers installed by the dealership. The first one failed and started wobbling bad at about 10 months. Under warranty they installed a new balancer and bolt. Then about two months out of the one year warranty the Balancer bolt worked its way completly loose and was resting on the PS rail. I was out on vacation and had another dealer install a new bolt and then one month later the balancer was wobbling very bad. The service manager just shook his head and said maybe a different balancer and bolt would work as the GM parts kept failing. So I bought a API Balancer from Summit Racing along with an ARP Bolt. About 435.00 total parts. Now I was asked by the tech that installed the API balancer and ARP Bolt if I wanted locktite or to used the lube that came with the ARP Bolt. After talking with the guys at ARP in Cali. we decided to go with the lube that came with the ARP Bolt. NOW>>>> if this does not work what would be next, outside of taking a gas can and a match to the vette? Any suggestions would be greatly appreciated as I am at wits end. Thanks.......

leadfoot4

Are you sure that someone, in the past, didn't strip the threads in the snout of the crank? If installed PROPERLY, there's no good reason for the crank bolt to simply fall out, unless the threads are bad.

FWIW, I installed an ATI balancer, using an ARP bolt, 2-3 years ago, on my C-5. I will admit that it's a low mileage car, but the bolt is still in place, after about 2000 miles. Keep in mind, 237 ft/lbs is a LOT of torque to apply to a bolt. It should not back out.......

nmbsun

Thanks for the input. What you just posted is what I am hoping to happen. From this Forum and others it seems that the original Harmonic Balancer and Original Bolt are crap. That is why I went with the ATI damper and ARP Bolt. I will say this, if this does not work I am going to get rid of my 2004 and take what money I can get and run like hell! As far as I know there is nothing wrong with the threads in the snout of the crankshaft. Three different techs have worked on my vette and I told the last one that if he found Anything Wrong with the snout of the crank let me know and I will have it fixed. He said he could not find anything wrong with the threads or the snout. WE SHALL SEE !!!!!

I forgot to mention that in Feb. 2005 there was a TSB released by GM that stated that there were reports of Harmonic Balancer Bolts backing completly out and the TSB gives complete instructions on how to fix the problem. BUT>>>>>that GM fix did not work. Then in 2012 GM released another TSB about the Bolt backing out. I don't think that fix worked either.

lar66BB

Don't use the OEM balancer they fail just like your original.
Rockauto Dayco PB1117N
Bolt Dorman 917139

Best prices I found

nmbsun

How many miles/months do you have on the Dayco and Dorman?

I forgot to mention that at this point price is not an issue. I just want the vette fixed period! That is why I spend the 435.00 for the ATI and ARP bolt.

vettenuts

The ATI and ARP bolt are top of the line products. As long as they were correctly installed, you shouldn't have an issue. However, if it does come loose there may be some damage to the crank itself as a result of prior issues. If that is the case, get the ATI pin kit and use that for the re-installation. That will keep it from spinning on the crank.

Note that removal of the ATI is done with different tools than the GM so if the service department is doing the work they need to be made aware of this.

wcsinx

The balancer bolt is a TTY (torque to yield) bolt meaning it stretches slightly when final torque is reached and thus is NOT reusable. So if someone told me their newly installed balancer bolt was backing out, my first instinct is that they didn't use a new bolt. (What dealership mechs say and do are rarely in alignment in my experience) So I suspect now that you've purchased a new ARP bolt (and top of the line balancer) your problems will disappear.

foggy

I replaced mine about 7 years ago.. At the time, I wasn't real educated on the differences.
I used the GM balancer and bolt.. I kinda figured if the OEM lasted 10 years *& 100K miles.. I could certainly deal with it..
Now I've only put about 20K on this replacement one, but all is good..
I suspect the original dealer that did your install F'ed up your crank threads..
OR just did the procedure incorrectly totally... Causing all your issues afterwards..
Good luck with the aftermarket stuff.. It's WAY Better.. just make sure they
really check the threads on the crank... And I'd PIN IT like suggested to add insurance that
this is the last time you have to deal with this issue

neutron82

I agree with having it pinned if they haven't already put the car back together... it will prevent the balancer from spinning on the crank as well as keeping the bolt from backing it's way out assuming that it is torqued properly

Gordy M

The original factory bolts can become loose, but usually under certain conditions, the vette was extensively used at a drag strip, heavy autocross use or HPDE use. When you run the engine for long periods at high rpms, the bolt was know to walk (come loose). Those who autocross in the street classes have to run OEM balancer and bolt, so when my bolt walked and I threw my serpentine belt, I replaced it my self. However, I made double sure it was torqued correctly and the balancer pinned. Thousands of autocross runs and several thousand miles of HPDE runs and it still is intact. If I did not have to have everything stock, I would have put in the ATI damper. Biggest problem is mechanics who tried to use a torque value to tighten the bolt. When I was turning it the extra 140 degrees, my beam torque wrench and extension pipe exceeded 300 lb-ft.

smoothsailing

How do you "pin" the balancer? What is the correct torgue? Will be doing this at home with my son a diesel tech. Noise coming from lower unit. Changed pullies already, still have the noise. Stock car no racing. Recommendations on brand?

Smoken1

Since your car is stock, I would use the Power bond PB1117N and the ARP bolt 234-2503 and a new front cover seal. The torque spec on the ARP bolt 235ft/lb

smoothsailing

Sure this is a dumb question, my son will know what you meant. But I don't, what cover seal are you referring to? Didn't think would be taking any covers off replacing the balancer. Again thanks for your help.

Smoken1

It is the seal that the balancer slides thru

Smoken1

This is a Pic of your front cover and the seal I was speaking of

neutron82

to add to that, since you have no need to take the cover off stop there and replace the seal with the cover still installed... if you remove the cover it will need to be properly centered around the crank or you risk your balancer hub chewing up the seal and causing an oil leak... been there done that

Ed Ramberger

Improper installation can easily be the cause. I've seen way too many people stating they wrapped a belt around the balancer or put a block under it. Both of these methods put abnormal stress into the rubber bond between the inner hub and the outer ring.

Also, the crank is what needs to be held as that is what the bolt is turning into. Holding the balancer is not the correct way to do it.

If they have damaged the crank at this point, that is not good. I would find out exactly how they have been holding assembly when tightening the bolt.

smoothsailing

Thank you all for your help on this. As soon as my son has a free Sat. we will tackle this. Appreciate the info I am sure it will help to do this right.

smoothsailing

Thank you all for your help on this. Somken1 used the parts you recommended. The install went well, several hours in my garage, the real pain on this install was the removal and reinstall of the rack and pinion assembly. Like a jig saw puzzle. Did not need to take off the sway bar. We were not positive the noise was the balancer, turned out it was. No noise after install.