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Discussion Starter #1
Good morning everybody,
Still looking for a vibration fix in my car. I've had the tires balanced twice. I've had the driveshaft balanced, a new slip yoke, and new universals. The front end and wheel bearings are OK, the engine and transmission mounts are ok. It runs smooth as silk up to 50 mph - vibrates like heck up to about 63 or so, then smooths back out. The driveshaft and universals seemed to make it worse. It used to vibrate at 55-60. It seems to be coming from the driveline somewhere and buzzes the dash, gearshift, steering wheel. I know these things are poltergists and hard to find, but does anybody have any suggestions on what to try next? ::

Thanks and have a great weekend,
Brian
 

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Did you have the same place balance your driveshaft both times? If so, perhaps you should try another shop. Sure sounds like the vibration I had, and it was my driveshaft. Wasn't missing any weights; but was actually bent!
 

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Brain,

Are you sure your transmission mount is OK? Mine looked fine and had no cracks and was still flexible but caused a very nasty vibration. The only difference between the old and the new one was the height (new one 1/4" higher) but boy what a difference!
 

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Tranny mount took care of my vibration - had metal on metal - rubber was gone. I, too, had the drive shaft and u-joints checked/balanced. Look the mounts over one more time.
 

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IF you are sure that it is coming out of the driveline area, then I would check tranny mount as suggested, then u-joints and yoke(s), and of course, the integrity of the driveline itself. If you are not sure it is coming from there, you might inspect some of the front suspension pieces, my car used to vibrate bad up at about 55-60, and I had a bad ball joint on a control arm. Good Luck

Dave
 

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Discussion Starter #7
Thanks for the responses folks. It was the tires I've had balanced twice, the driveshaft has only been balanced once. The yoke and universals are brand new. I'll take another look at the tranny mount. One of the guys here at work is saying he thinks it may be a warped flywheel or pressure plate. HE said a symptom of that is if it shudders in reverse. It does do this. Does this sound reasonable? I've got a leaky rear main seal I need to get into anyway so maybe resurfacing the flywheel and a new clutch would be a good thing. What do ya'll think???
Thanks
 

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I agree with others that you can't always tell what condition the mounts are by looking at them.

When you replaced the slip yoke, did it show any wear? Simply replacing the yoke will not fix the problem if the tailshaft bushing is worn (don't ask). I had such a problem, and it plagued me for years. You always feel silly that it took so long to find the simple problem!

If it were an imbalance, it wouldn't go away at higher speed. Since it only exists in a certain speed range, I would suspect a harmonics problem with spinning parts, such as bushings, bearings, etc, or possibly mounts. Is there any slop in the rearend yoke bearing? You could be running into a harmonics problem if the angle of the front U-joint is different than the rear U-joint.

Keep after it, and Good Luck!
 

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Just for giggles, try removing the shaft at the rear yoke, rotate 180* and reinstall. Then check your vibration.
 
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