vibration at 62 mph: Im out of my mind!

[DocMel]

71 Cuda:  440 engine, 3:23, 727

I have had this car for about 4 years now.  I have changed these out since:
-All front suspension bushings, pitman arm, every single part of the front suspension that can wear out
-Front wheel bearings
-All u joints and had the driveshaft balanced
-Just rechecked all tire balancing
-Switched front wheel to back and vice versa

Car runs down the road smooth until about 62 mph (my tach doesnt work).  Then I get the vibration: Its fairly bad.   It goes away at about 70 mph
It does feel as if its in the front   This is really driving me nuts

Can anyone plz help me with this?

[DocMel]

Forgot to add:   I also changed out the yoke when the driveshaft was balanced.  It was wore out.   It may have improved the vibration slightly, but it could be my imagination

[brads70]

I had one like that on our old family car. Turned out to be a balance weight had fallen off one of the brake drums.  I too balenced all the tires, replaced the shocks...etc.... 

Just an idea?

[brads70]

Forgot to add:   I also changed out the yoke when the driveshaft was balanced.  It was wore out.   It may have improved the vibration slightly, but it could be my imagination

Tailshaft bushing?

[_Russ_]

I have no idea, but a little more info might help nail it down.

Is the vibration coming through the steering wheel? or does the entire car vibrate?

[fantum]

Did you try doing 62 in second and see if the problem goes away?  Doing so will help in troubleshooting this problem.

[dodj]

If you get it up to say, 70, then take it out of gear. Does it still vibrate at 62 mph?

[72ls5fla]

check the alternator ---   I had a bearing go bad one and it felt like the car ws going to vibrate apart.

Also - could be a bad bearing in the water pump...

Bill

[Chryco Psycho]

BFG tires are not round even when balanced properly

[nqkjw]

BFG tires are not round even when balanced properly

Neither are Coopers as I've just found out