Balancer Bolt....................
Thread Starter
Burning Brakes
Joined: Sep 2003
Posts: 1,106
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From: Norwich NY
Balancer Bolt....................
I am thinkin about putting in a bigger cam. It appears most of the work is more time consuming than difficult.. One thing seems to be a bear though...
How do you torque the balancer to 350 ft lbs?? My wrench goes to 200..
There has to be a trick to it.. At least I hope so..
Thanks in advance.
How do you torque the balancer to 350 ft lbs?? My wrench goes to 200..
There has to be a trick to it.. At least I hope so..
Thanks in advance.
Drifting
Joined: May 2000
Posts: 1,413
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From: Wildwood MO
I used a digital torque gage on a long breaker bar. Not only is this bolt very important to get torqued correctly, you must also keep the engine from turning while torqueing the bolt. I used a special fixture from GM that bolts in place of the starter and engages the teeth of the flywheel to keep the engine from rotating. Just putting the car in gear is not enough, cause there is too much flexing in the drivetrain.
Drifting
Joined: May 2000
Posts: 1,413
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From: Wildwood MO
I used a digital torque gage on a long breaker bar. Not only is this bolt very important to get torqued correctly, you must also rotate it a certain # of degrees after its torqued. Keeping the engine from turning while torqueing the bolt is a real task too. I used a special fixture from GM that bolts in place of the starter and engages the teeth of the flywheel to keep the engine from rotating. Just putting the car in gear is not enough, cause there is too much flexing in the drivetrain.
Team Owner
Joined: Sep 2001
Posts: 23,283
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From: Lake Elsinore, CA
I've done several of these. On the M6's, I put it in 5th to torque the bolt. On the A4, I used a screwdriver to keep the flexplate from turning. The initial 240 ft. lb. torque using the old bolt will press the pulley onto the snout a certain distance. The remaining angle torqueing will strtch the balancer bolt to a certain tension to prevent the pulley from backing it out. Below is the distance spec from the manual that should be measure after the initial 240 ft. lb. torqueing and before the 140 degree bolt stretch. I measured this distance after the initial torqueing and the belts lined up nicely.
Notice the marks on my pulley showing the completed 140 degree torque on the bolt head.
Notice the marks on my pulley showing the completed 140 degree torque on the bolt head.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
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From: King George VA
There are several lessons learned about taking this bolt out and putting in a new one. I wish I had read them before doing some pre-runoffs work on the inside of my motor.
Here is my sad story:
http://forums.corvetteforum.com/showthread.php?t=922738
Here is my sad story:
http://forums.corvetteforum.com/showthread.php?t=922738
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Pro
Joined: Jul 2003
Posts: 688
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From: Dover AFB DE
What do you do about balancing the Harmonic Balancer? I know the book says to scribe and reinstall in the same position or if replacing, add the weights in the same location.
I had my bolt loosen, which I've seen/read about a lot of them doing that, so my HB wasn't in the original location. I just installed it. How do you overcome harmonic vibration if putting on an HB without weights?
I know a lot of you have pulled your engines and built them up, so I'm looking for your experience.
I had my bolt loosen, which I've seen/read about a lot of them doing that, so my HB wasn't in the original location. I just installed it. How do you overcome harmonic vibration if putting on an HB without weights?
I know a lot of you have pulled your engines and built them up, so I'm looking for your experience.
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Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Originally Posted by jjcslynn
What do you do about balancing the Harmonic Balancer? I know the book says to scribe and reinstall in the same position or if replacing, add the weights in the same location.
I had my bolt loosen, which I've seen/read about a lot of them doing that, so my HB wasn't in the original location. I just installed it. How do you overcome harmonic vibration if putting on an HB without weights?
I know a lot of you have pulled your engines and built them up, so I'm looking for your experience.
I had my bolt loosen, which I've seen/read about a lot of them doing that, so my HB wasn't in the original location. I just installed it. How do you overcome harmonic vibration if putting on an HB without weights?
I know a lot of you have pulled your engines and built them up, so I'm looking for your experience.
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Team Owner
Joined: Nov 1999
Posts: 26,679
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From: This vette goes to 11 Milford MA
St. Jude Donor '03-'05
Now I'm wondering if mine is going to fly off. I only have a 150 toque wrench so I basically tightened it until it was in about 3-4mm and then did the 37/140* thing but without loctite.
Team Owner
Joined: Sep 2001
Posts: 23,283
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From: Lake Elsinore, CA
Fastguy, that's what I have done on several - torque to .125" and then 37ft. lb. and 140 deg. Never had a new pulley back out yet. The 240 ft'lb. is a torque which yields the correct displacement in the pulley relative to the crank - in other words, the distance pressed on is accomplished via a torque spec.
I have heard of a few re-used pulleys coming out, probably because the press fit on the pulley bore is relaxed after the first install. I got AL shavings from the 2 ASP UD pulleys I have installed indicating a verry tight press fit. I've spooled mine to ~6700 many times with no problem.
I have heard of a few re-used pulleys coming out, probably because the press fit on the pulley bore is relaxed after the first install. I got AL shavings from the 2 ASP UD pulleys I have installed indicating a verry tight press fit. I've spooled mine to ~6700 many times with no problem.
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From: King George VA
Originally Posted by Fastguy
Now I'm wondering if mine is going to fly off. I only have a 150 toque wrench so I basically tightened it until it was in about 3-4mm and then did the 37/140* thing but without loctite.
I would suggest you keep a close eye on the bolt for awhile.
As an FYI, my first indication that something was wrong was the smell of burning oil. I believe that as the bolt came out, oil sprayed by the front seal on the crankshaft into the engine bay and some got on the exhaust. The second sign was the power steering getting stiff as the belt slipped, but voltage was still fine as was oil pressure. So, if you smell burning oil, turn the car off asap.
Team Owner
Joined: Nov 1999
Posts: 26,679
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From: This vette goes to 11 Milford MA
St. Jude Donor '03-'05
Well, its not a new pulley, its the old one but its the first time being off. Once its back together, its off to the dyno and then 11/19 and 11/20 at Lime Rock so I really will have to keep an eye on it. Nothing like spraying oil on the front tires going 150mph.
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From: King George VA
Originally Posted by Fastguy
Well, its not a new pulley, its the old one but its the first time being off. Once its back together, its off to the dyno and then 11/19 and 11/20 at Lime Rock so I really will have to keep an eye on it. Nothing like spraying oil on the front tires going 150mph.
I wouldn't worry too much about the oil on the front tires. I went through several corners smelling the smoke before I pulled over to a corner worker stand and didn't notice any loss of traction on the front or rear tires. I think most of the oil blew around in the engine bay and very little if any hit the ground before the rear tires. But, as soon as I smelled the smoke, I did back out of it checking gages, etc.
Drifting
Joined: Dec 2003
Posts: 1,268
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From: Ca
Hey Sub!
Thanx for the post...your description and results finally helps me to understand what in part happened to my 382 stroker...almost identical in every respect(occurance and block destruction) too expensive for same stroker short block...went with LPE short block 350...cost effective at this point!
Sorry to hear about your troubles...I'm with you man!
Thanx for the post...your description and results finally helps me to understand what in part happened to my 382 stroker...almost identical in every respect(occurance and block destruction) too expensive for same stroker short block...went with LPE short block 350...cost effective at this point!
Sorry to hear about your troubles...I'm with you man!
Racer
Joined: Oct 2001
Posts: 483
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From: Downingtown PA
The mechanic that replaced mine said he torqued the bolt by having two guys hang on the end of a big breaker bar. Sounds a little crazy, but that was two years and several track days ago. No problems. Good luck with yours.
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Joined: Aug 2001
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From: King George VA
Originally Posted by AMERICANMUSL
Hey Sub!
Thanx for the post...your description and results finally helps me to understand what in part happened to my 382 stroker...almost identical in every respect(occurance and block destruction) too expensive for same stroker short block...went with LPE short block 350...cost effective at this point!
Sorry to hear about your troubles...I'm with you man!
Thanx for the post...your description and results finally helps me to understand what in part happened to my 382 stroker...almost identical in every respect(occurance and block destruction) too expensive for same stroker short block...went with LPE short block 350...cost effective at this point!
Sorry to hear about your troubles...I'm with you man!
Wish I had read all of these posts before taking my motor apart... painful way to live and learn, eh?
