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Old 04-17-2008, 02:04 PM
Aaronz28 Aaronz28 is offline
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Join Date: Jun 2004
Posts: 225
Default vibration that goes away at 70mph

So, finally got my 64 Bonnie all back together.

With a 700r4 and 4.88 gears i get a rather nasty vibration from 55-70mph, but as soon as you exceed 70mph.. it goes away and is as smooth as can be.

I had 3.08 gears in the car and didn't notice it. But the 3.08 just seem to low for the .70 overdrive of the 700r4.

At one time I had a TKO500 in the car and noticed it with the 4.88s also.

I just installed a set of asjustable upper rear and tubular lower rear controll arms to get the pinion angle set.

I suspect my trans tailshaft could be off, since i had to fab up a GTO crossmember to work with the exhaust.

Can anyone tell me what type of angles I need to look for? Of course, I can lower the trans some, but not much becasue it will smack my exhaust.

Any help would be greatly appreciated.

Thanks

Aaron

  #2  
Old 04-17-2008, 10:56 PM
"QUICK-SILVER" "QUICK-SILVER" is offline
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Location: Alexander City, Alabama
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Two different transmissions, two different rearends and two different u-joint combination angles but it only does it with one thing, the 4.88s.

I say, need a high speed balance on the driveshaft.

  #3  
Old 04-18-2008, 08:37 AM
Aaronz28 Aaronz28 is offline
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thats exactly what I plan to have done today

Thanks

Aaron

  #4  
Old 04-18-2008, 07:19 PM
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issach428 issach428 is offline
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had the same problem with my truck. Had the tire's re-balance and it went away.

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  #5  
Old 04-21-2008, 09:39 PM
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just501 just501 is offline
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I had this same problem, vib from 55-70 mph and went away if faster or slower and it didn't matter if the trans. was in 3rd or 4th gear. Had stock 14" rally II wheels checked for balance and checked okay, but when I swapped wheels to 17" Cragar SS, the vibration went away completely. Don't know if the angles changed with the wheel swap, or if it was the wheels themselves. Hope this helps.

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