Need Diagnostic Help - Bad Vibration

[Alaska Aviator]

I've got this nagging problem. At about 68 mph I get a pretty bad vibration and mild rattling noise - not rpm dependent but speed dependent - happens in overdrive or drive. The vibration and noise go away about 72 and it smoothes out.

I can throw the trans in N and let engine idle and it is still vibrating if I'm going faster than 68.

I've had the wheels and tires balanced several times - I've had the drive shaft balanced and u-joints replaced. It also did it before my transmission was rebuilt with new torque converter, so it's not that.

Any help appreciated!

TIA

:(
AA

[Dvldog 8793]

Howdy
(1) Wheel bearings
(2) Drive shaft balance
(3) rear end problems
(4) axle problems
The drive shaft you can pull and have balanced
The wheel bearings I would just replace
The rear end should be checked by someone that is good at setting them up properly
The same guy/gal would know how to check your axles.
Hope this helps!!!!
L8r

[kconnair]

You might look into wheel or rotor run-out (bent rim or warped rotor), rear drums out of round, or a thrown belt in your tires. Balancing won't fix any of these problems.

If it is lifted a bunch, you may have a driveline angle problem.

Hope this helps,

Kevin.

[rwpierce]

A front shock bracket rubber bushing wore out

[dieselbegreat]

brake rotor(s) or tires out of balance/round/true. replace all rotating mass components until it smoothes out. sorry. :mad: