Rotating Ballancer 90 deg. ???
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Registered User
Joined: Jul 2003
Posts: 242
From: Gainesville, FL
Rotating Ballancer 90 deg. ???
I just read in an old post that you can rotate the harmonic ballancer 90 degrees to see if it helps reduce vibrations. I currently have a vibration that accurs in my motor when I am in nuetral and rev it to 2,000-2,500 rpms. This also makes the car vibrate in gear when I am crusing in that rpm range no matter what gear I am in. I was just wondering if this is true and if it would be worth my time to try it.
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Joined: Dec 1969
Posts: 27,728
From: Little Rock, AR
IMO, the only reason you might want to try that is if you have reason to believe that the position of the hub had been altered from stock. You might want to be sure you just don't have a miss.
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Joined: Aug 2002
Posts: 2,356
From: Madison Heights, MI
Originally posted by stew's94z
It also has three holes so you can only turn the harmonic balancer 120 degrees on the hub. It would take four holes to turn 90 degrees.
Dean
It also has three holes so you can only turn the harmonic balancer 120 degrees on the hub. It would take four holes to turn 90 degrees.
Dean
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Joined: Nov 2001
Posts: 719
From: Summerfield, NC USA
Originally posted by stew's94z
It also has three holes so you can only turn the harmonic balancer 120 degrees on the hub. It would take four holes to turn 90 degrees.
Dean
It also has three holes so you can only turn the harmonic balancer 120 degrees on the hub. It would take four holes to turn 90 degrees.
Dean
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Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Here's the refererence found in "Rebuilding the LT1".
HUB AND BALANCER
The balancer is a two-piece assembly with a pulley that bolts onto the hub. Separating the two made it easier to install the Optispark distributor on the assembly line and out in the field. The holes in the hub are offset, so the balancer only fits on it one way, but there’s no keyway in the hub to index the hub on the crank. This shouldn’t be a problem unless the damper was drilled at the factory to "trim" the final engine assembly.
If it was drilled a lot to compensate for an engine that was out of balance, you could end up with a shaker, depending on how everything stacked up with the remanufactured engine compared to the original engine. If you encounter a balance problem on a remanufactured LT1, try rotating the balancer assembly on the crank 90° at a time to see if it eliminates the problem.
The balancer is a two-piece assembly with a pulley that bolts onto the hub. Separating the two made it easier to install the Optispark distributor on the assembly line and out in the field. The holes in the hub are offset, so the balancer only fits on it one way, but there’s no keyway in the hub to index the hub on the crank. This shouldn’t be a problem unless the damper was drilled at the factory to "trim" the final engine assembly.
If it was drilled a lot to compensate for an engine that was out of balance, you could end up with a shaker, depending on how everything stacked up with the remanufactured engine compared to the original engine. If you encounter a balance problem on a remanufactured LT1, try rotating the balancer assembly on the crank 90° at a time to see if it eliminates the problem.
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Joined: Feb 2000
Posts: 2,026
From: Japan
I wonder what could cause this wobble to start happening a while after the engine has been rebuilt. Say 10-20,000 miles for example.
I have this problem with my rebuilt engine and it started after I changed the clutch. I put the original PP back in after it started happening because I figured that it caused the problem and the wobble has stuck with it ever since.
I still have the same flywheel too.
I have this problem with my rebuilt engine and it started after I changed the clutch. I put the original PP back in after it started happening because I figured that it caused the problem and the wobble has stuck with it ever since.
I still have the same flywheel too.
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Joined: May 1999
Posts: 2,201
From: HI.
I'm putting my motor together and was wondering (when putting a motor together thats not good to do) this. When I put my hub on, it can just go on any way???? There is no keyway but the manual says to mark it when removing and replacing. Why is this?
Thanks.
Thanks.
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Joined: Nov 2001
Posts: 719
From: Summerfield, NC USA
for some reason the factory didn't think it was necessary to put a keyway on it, and for the most part it works just fine.
in the service manual it says to find TDC and place the hub so the arrow is straight up.
95, could have wound out or hub spun a little causing it to become off balance. Everything is supposed to be neutral balance from what I have read, but check your balancer to be sure that none of the elastomer is sticking out, that would tell you the pulley spun on it's hub and it's no longer good.
Thats one thing I'm worried about w/ this LT4 conversion and programming, when I'm about 1/3 throttle and it drops into 3rd, you can hear the fan belt chirp, I'm just wondering when it's going to take the pulley w/ it..
in the service manual it says to find TDC and place the hub so the arrow is straight up.
95, could have wound out or hub spun a little causing it to become off balance. Everything is supposed to be neutral balance from what I have read, but check your balancer to be sure that none of the elastomer is sticking out, that would tell you the pulley spun on it's hub and it's no longer good.
Thats one thing I'm worried about w/ this LT4 conversion and programming, when I'm about 1/3 throttle and it drops into 3rd, you can hear the fan belt chirp, I'm just wondering when it's going to take the pulley w/ it..
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Joined: May 1999
Posts: 2,201
From: HI.
Originally posted by Hotwire
Thats one thing I'm worried about w/ this LT4 conversion and programming, when I'm about 1/3 throttle and it drops into 3rd, you can hear the fan belt chirp, I'm just wondering when it's going to take the pulley w/ it..
Thats one thing I'm worried about w/ this LT4 conversion and programming, when I'm about 1/3 throttle and it drops into 3rd, you can hear the fan belt chirp, I'm just wondering when it's going to take the pulley w/ it..
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Joined: Nov 2001
Posts: 719
From: Summerfield, NC USA
Originally posted by S.J.S.
That's just an old belt from what it sounds like.
That's just an old belt from what it sounds like.