loud vibration

[stlouischiefs]

So I was driving down to the lake for the weekend. Get off the highway and come to a stop. Once I started going I had a vibration along the lines of what you feel driving over the bumps on the side of the road. Once I got to 50 or so the noise was still there, albeit louder, then it just stopped and the truck felt normal again....until I stopped at a light. Once I start going again it started the vibration around 30th or so and continues on again until it magically stops. Made it to the lake and went to sleep. Next day no tyranny fluid because the rear seal just came out. Got it back in. Added fluid and drove fine...except for the vibration. Chanel out the differential fluid and same results. Anyone have any ideas? I'm still at the lake and need to go home today so I want to get this fixed instead of driving with it as it is..

Editt. This is a 1998 ranger xlt 2.5 btw

 

[Spott]

I'd start by looking at the U-joints and the driveshaft. If a U-joint is bad, it will also often make a "clank" each time you switch from acceleration to deceleration and vice-versa.

If the driveshaft was vibrating badly, this may explain why the transmission seal shook loose.

 

[stlouischiefs]

Any reason that it would "correct" itself eventually at high speed? I'll get to about 60 and it will vibrate for a while then it just returns to normal until I slow down again . And by that I mean it's usually fine until I stop and then move again.

 

[Spott]

It's entirely possible. When the vibration is near the right frequency, a small bump may jar it into a good "centered" position, and it will stay jammed there until the force is removed from the drivetrain. Then gravity will pull it off to the side again, and the vibration returns.