Vibration in rear end.

[combat.vet91b]

I have a 1997 Ford Expedtion 4.6l XLT that has a slight vibration at 30 mph and increases to a heavy vibration at 70 mph the part that confuses me is that at 60 mph the vibration decreases to the same as the 30 mph. any info would be very helpful. thank you

 

[BAD RONALD]

Universal joints? Just a guess. Could be a tranny shudder.

Try searching both the conditions. You probably can view a video that matches the problem with your truck.

Is the problem consistent after a tire rotation? Is this a RWD vehicle?

 

[tonydiv]

When was the last time:

The tires have been balanced
Driveline and suspension were checked out
Shocks were replaced
Tires were checked for slipped belts

 

[Dizzy]

Had the same issue on my 2000. Put new u-joints in and rides smooth as silk.

Dizzy