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Old 02-25-08, 07:48PM   #1
Josh
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Default Getting pissed at my harmonic balancer.

I have a 72 LeMans 400 stroker. I just got it out of the shop 3 weeks ago from getting a complete rebuild on the engine, trans and rear end and have been trying to drive it as much as possible to let the rings and new seals seat. I was driving it this past Saturday and out of no where I heard a clinking noise, I was about 2 blocks away from my house so I decided to wait until I got home to check it out. Well I didnt quite make it. As soon as I pulled into my driveway I heard the drive pulleys fall off and of course I lost all power steering, water pump etc.

How does that even happen? I crawled under my car and tried to put the pulleys back on the harmonic balancer but it feels like the bolts can only be tightened so far, then it loosens up again. Im assuming that there were some bolts that maybe held the screws, after I had that ephifany I tried for the next hour and a half trying to take off the harmonic balancer. I was putting everything I had into taking off that huge bolt that holds it onto the crank i assume, but I got no where.

Do I need some special tool to take if off? And do I even need to take it off? Can someone help me with how to put the drive pully back on? Im upset at the fact that I have to do it in the first place, after I spent all that money getting everything rebuild. Thanks in advance for the assistance.

Josh
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Old 02-26-08, 12:52AM   #2
Gach
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It sounds like the bolts that hold the drive pulley on are striped, if you
tighten and they losen..their striped ( make sure they have lock washers on them ). The balancer bolt is torqued to 160 ft lbs. You'll need a long breaker bar and socket to loosen it.You'll also need some one to hold a screw driver in one of the teeth of the flywheel with the screw driver braced against the frame so when you try and loosen the balancer bolt it'll keep the motor from turning over. Get the biggest and longest screw driver, you can find. Might have to take the trany shield off that covers
the flywheel to get at it.

Make sure the bolts that hold the pulley on has lock washers.
If you have access to a in-pack gun you might be able to spin
the balancer bolt off with it..some of the in-pack guns go up
to 160 lb torque. Now if the bolt holds that hold the pulley on
are striped..two things you can do #1 hile coil them #2 get another
balancer.

When you get the balancer off take it to a hardware store and
ask for a hile coil kit..for that thread size, it comes with a drill bit
drill the holds out and install the hili coils, it's pretty easy to do.
and is stronger then the threads that were in your balancer..
Use new bolts and lock washers to install the pulley. You'll need
to re-torque that balancer to 160 ft lbs..check and make sure
those are the torques spec's I'm not 100% sure it's 160 ft lbs.
but again you'll need help some one to hold the screw driver
in the flywheel. The also make a flywheel tool..I have one
that holds the flywheel from moving..I think it's like $75.00
bucks..maybe you can borrow one from a friend or garage.
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Old 02-26-08, 01:16PM   #3
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I hope this is a hobby car and you have patience 'cause this could get ugly. It may not be all that bad though so just take your time.
If your balancer is a real good fit as it should be, you would need a balancer puller to remove it. This poses a problem because it appears that the threads of your balancer are stripped out. You still have a few options though.
First, confirm that the threads are gone. Next decide weather you are going to keep this balancer or replace it.
If you are keeping it, you need to heli-coil it or tap it up to the next size thread. This may take some effort and you may have more space to perform your operation if you remove the radiator - your call. Either way, I am not real familliar with the effects of drilling or tapping all different brands of balancers - I would remove as little material as possible and try to make them all as even as possible (personally, I would replace it) so as to not affect its ability to do it's job at higher rpms (less critical with low rpm mill).
After you have new threads, use the appropriate bolts to re-install the pully - If you tapped the next larger size, you may have to drill the pully holes for the new bolt size to pass through.
If you are going to replace it - I would tac weld studs to it and use the puller to remove it, then throw it as far as I could. You can also go through the effort of threading to the next size and then using the puller if you do not have a welder - and then throw it as far as you can. Then install new balancer - I like to use threaded rod and then remove it and complete install with the heavy waser and balancer bolt.

Also, when using the puller, make sure to use a centering point of small head allen bolt in the crank - you do not want to mess up those threads.

Hope this helps. Have fun.
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Old 02-26-08, 02:00PM   #4
Bruce Wilkie
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Lugnuts67; you should NOT need a balancer puller on a STOCK PONTIAC balancer unless there is rust or damage of some type. They are not normally an interference fit like the "other" brands! There is a reason for the 160 ft/lb torque spec.

Adding helicoils will NOT upset the balance of the balancer either.

He should not have to remove the radiator to remove the balancer.

Last edited by Bruce Wilkie : 02-26-08 at 02:07PM. Reason: correction
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Old 02-26-08, 04:30PM   #5
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Good info Bruce. I will try to remember that. I have not been lucky enough to slip off a balancer - mine have been pretty tight or old or both - but he did also say that his was 3 weeks out of the shop so it will probably slide right off. However, he did not specify if it was a STOCK PONTIAC balancer or not. It has been my experience that the tigher fitting balancers do a better job of dampening harmonics and even press fit balancers have torque specifications on the retaining bolt. The purpose of the balancer is to absorb harmonics, dampen vibrations, and it is less effective if there is a sloppy fit between crank and balancer.
I am always over cautious with rotating mass. The closer to the centerline of the crank the less effect it has on balance and being as they will be equaly spaced bolts close to the crank center there is not a great chance of causing significant imbalance but any time I remove metal from a rotating assembly, I am mindful of balance. This is a 400 stroker - I do not know it's purpose, operating rpm or the manufacturer of the balancer- so I would again be over cautious.
You may not have to remove the radiator. You just need to get a drill in there and drill straight down the holes. I would probably try to get in there with the drill to make it as straight a shot as possible. Do whatever makes the job easiest for you. If you spin the engine over you may not need to do anything to get a comfortable shot at it - just rotate until the hole you are working on is in a good spot for you. The center of mine points above horizontal and I would pull the rad on mine.
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Old 02-26-08, 06:08PM   #6
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I've had to use a balancer puller on rare occasions on old slip fit balancers when doing timing chains and stuff. I think oldsmobubble has the same setup if I'm not mistaken.

Balance shouldn't be a problem with it comes to putting in some heli-coils. It would take ALOT more weight to actually feel something in the balance in that regard.

Snap-on makes a tool. It's like a long pry bar with a chain to hold the balancer as well making it a one man job cracking and tightening the big harmonic balancer bolt. Of course the cheaper tool is a flywheel holder, but you'll need a freind to help you with that.

Don't have an impact gun and shop air?
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Old 02-27-08, 05:19AM   #7
sprint250
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Default I lieu of impact wrench.

OK I know I'm gonna get some flack on this one but here goes.

1- 1/2" drive 15/16 impact socket (deep)
1 good quaulity breaker bar long enough to brace against the frame or some 4x4s to oppose the direction of engine rotation.
If the socket wants to fall off the bolt , support the end of the socket with a
4x4.
Refrain from using drive extentions .You want all the breakaway torque to be tranmitted to the bolt and the bar.Extensions twist and absorb some torque.
Disconnect the primary (+) wire to the coil.
Get your tools in position. Bump the starter.
The bolt will break free and you can wind it the rest of the way out by hand.

Now I've done this at wrecking yards, out on the road and in the shop too when there was no air and no extra set of hands or any tool to hold anything at the flywheel.
Desperate times call for desperate measures.

Word of caution here:
DO NOT HOLD ONTO THE BAR ! BRACE IT OFF SAFELY AND STAND CLEAR.
In rare cases the head of the bolt could shear off but if the bolt is that weak already or is rusted or some Cretin put it in with Loctite the impact wrench or BFH would probably do the same thing.
Other horror story is the posiibility of twisting the crank,breaking the crank,
breaking the snout off the crank.
Heard of it happening, been told it can happen, never seen it happen.

If you are not sure before starting good insurance would be to heat the head of the bolt with an oxy acetylene torch too about 500 degrees ( that's plenty any hotter and there may be other problems) and let it set for a few minutes then try and break the bolt loose
That would hopefully break the bond of any possible corrosion and cause a thread locker to soften enough to allow the bolt to break free.
If you do not trust re using the old bolt get a new one.


I would not take a chain / toothed type tong wrench to the inertia ring on a dampner.It would work but the elastomer bond between the hub and the ring may not like it either depending on how hard you have to twist against it.
If it is an old dampner it may already be slipping anyway.

I've seen some guys assemble the dampner on the crank snout with Loctite.
I guess they have reasons?
If you are not aware of this when trying to remove a dampner it will give you fits.

So if you are having to use excessive force to get the puller to work that may be the case or it is just a very tight interference fit that may require some warming to get it to slide off.If you force it the lead screw to the puller may strip or the dampner may gall itself to the snout on the way out.
The dampner hub may have to be heated to break the bond of the thread locker / sleeve retainer glue that was used.
You just do not want to get the hub so hot that it screws up the elastomer bond or the front main seal either. Damp rags tied around the ring may help to heat sink it.
If it is a junk dampner to start with your going to pitch it once it is off ,so all is fair. If in doubt replace the front main seal too.

No warranty ,gauranty is expressed or implied.
Use this at your own peril.

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Old 02-27-08, 05:37PM   #8
Josh
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Thanks guys! I think im going to go get a bigger breaker bar. Sprint, thanks for the advise but that seems a little over my head and I dont have a torch that I can use.

The bolts are definately not stripped, but maybe the holes in the balancer are. But all four of them? I looked in the holes the best I could and they didnt look stripped, but Ive changed the bolts so that just leaves the holes. If I could get the damn balancer off, I would just replace it. Its hard for me to do because the car is on ramps and I have limited mobility. Just to add to the problem, I think that Loctite was used on the bolt.

I think that due to my lack of experience and tools at hand Im going to have to use the hile kit. Ive never used one but Im hoping that its not too difficult. Im not the greatest mechanic, which is why it went to the shop in the first place.

Does anyone know how this could of happened?

Thanks again and Ill keep everyone updated on my frustration...I mean progress.
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Old 02-28-08, 01:02AM   #9
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First I wouled make sure the bolts arze the right size and second would run a tap into the holes on the balancer ,sounds suspiciously like too small a bolt.
Len
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Old 02-28-08, 10:03AM   #10
Bruce Wilkie
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Bolts too small or bolt shank above threads too long(and thin). Also support ring on wrong side of pulley will cause the bolts to loosen.
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Old 02-28-08, 11:01AM   #11
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I have a question along the same lines, I would like to change my balancer that is currently on the engine mounted on an engine stand ( flexplate not installed) is there a feirly easy trick to get the bolt off.
Thanks,
Deno
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Old 02-28-08, 11:42AM   #12
Josh
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Im fairly sure the bolts are the correct size because they actually do tighten, but just to a certain point. There isnt a shank on the bolt its threaded all the way to the head. Dennis where does the support ring go? Between the pulleys and the balancer or on the inside of the pulleys? I currently have it between the pulley and balancer, but it looks like it could go either way.
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Old 03-01-08, 03:13AM   #13
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Quote:
Originally Posted by Josh View Post
Im fairly sure the bolts are the correct size because they actually do tighten, but just to a certain point. There isnt a shank on the bolt its threaded all the way to the head. Dennis where does the support ring go? Between the pulleys and the balancer or on the inside of the pulleys? I currently have it between the pulley and balancer, but it looks like it could go either way.
Sounds like you've got a course threaded bolt trying to thread into a fine threaded balancer or visa versa.

Did you get the main bolt off? With all the room between the balancer and the radiator, you could easily get a 1/2 inch impact gun on there to get the main balancer bolt off. Don't have a friend with a 1/2 impact gun and a portable air compressor? You'd have that sucker off in a second.
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Old 03-01-08, 07:50PM   #14
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The reinforcement plate goes between the bolts and the pulley, not between the pulley and the balancer. To get the balancer off it is easiest to buy a 2-foot section of pipe that will go over the handle of your breaker bar. Then find a way to block the flywheel, either with a screwdriver or a flywheel turning tool. It is best to have a helper jam the flywheel, but it is possible for you to do it by yourself. You will be able to figure out the problem with the balancer off. I have never had a bolt I could not get off this way.
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Old 03-01-08, 10:52PM   #15
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Bolts, reinforcement ring, pulley! installing the ring behind the pulley gives misalignment and causes the bolts to loosen. Make sure you have the right thread screws.
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