Hi all,

been reading several older articles about this issue. Wheels and tires were just remounted and balanced by Ford dealer. They diagnosed the drivetrain and claim that when they lifted the truck and put in drive, they found the rear pinion seal to move, which they said should be stationary. They said that if they take the next step which is to remove the rear diff cover, there is risk they can't put it back together? I challenged this because it doesn't make sense to me- not sure why they can't visually check the differential components. I then asked why we dont just change the seal, and they said it wont be of help, because there is something that caused that seal to go back.

Truck has 124k miles. Runs great, no noise from the diff, just shakes under my seat a lot when going 65-70. Sometimes when i go quicker, it smoothes out a bit.

Thoughts?

 

If there is that much movement at the seal, it should be leaking.

 

It is leaking. Do you think replacing the seal will help with the vibration? Thoughts on next steps?

 

Ask around.... locate an independent garage.
Tell them you have a leak at that seal AND the 65-70 vibe.
I bet you'll get clearer communications.

Were I in your situation, I'd tell the mechanic about the leak/seal and ask him to do a diff cleanout/inspection and fluid renew.
Also, at 1224K, having the driveshaft balanced and U-Joints checked isn't too extravagant an idea.

 

That is the speed where tire balance is usually the problem. Take it to another tire shop and get another balance. You could have easily thrown a balance weight. Out of round or a rim problem could also be at fault. In my experience driveshaft out of balance usually happens more at lower speeds like 45 to 50.