98 Windstar, drivetrain vibration solved.

Thought someone might find this useful.

My van has about 160K miles, and for like 5yrs has had an annoying vibration under acceleration. It was most noticable when accelerating up a hill from a dead stop. Most people probably wouldn't care, but it bugged the crap out of me.

Anyway, I got an opportunity to work on the front end while replacing the wheel bearings. These were damaged back in August and have been singing while cornering ever since. I'm certain the bearings got damaged when I drove over some asphault that had been milled for re-surfacing. The knucklehead operating the milling-machine left a step at the end. When I hit it, I thought for sure I bent some rims, or wrecked some tires. After a few miles, I realized how lucky I was that I didn't. About 3wks later the bearings started making some noise. My annual state inspection was due, so I needed to replace the bearings.

I decided to replace both half-shafts with NEW ones while I was at it, primarily because they were under $70 each. The job is done and the wheel bearing no longer sing while turning. The vibration is totally GONE. My van hasn't driven this smooth for as long as I can remember. It drives like a NEW car...no kidding. I now wish I had done this sooner.

Anyway, I hope someone finds this useful.

So, most likely, the vibration you had was caused by your worn half shafts. I had a similar problem on a different vehicle. There was play in the half shaft if you grabbed it in the middle and moved it laterally to its axis, ie. up and down and back and forth. It did NOT have any significant wear inside the joints that typically accompanies a noisy cv joint heard when cornering hard forward or reverse or when from a fast start on a steep hill like yours. The worst wear was actually the splined end as it entered the trans. I tried rebalancing tires over and over. Running the car on jacks to check for the vibration with and without tires. Now all is well. I did have to rotate one tire up front to the back as it did create a vibration. Haven't had to replace the bearings yet. :)