Grinding/vibration when starting from a stop.

[jhbpilot]

Hi guys. I have a 2004 xlt 2wd. When starting from a stop I'm getting this grinding noise from what sounds like the rear of the truck. Seems to be worse making a turn at normal acceleration. However also get it when accelerating straight ahead just not as often. Rear end rebuilt by ford dealership 5 years and 50000 miles ago. One wheel bearing in rear was replaced 25000ish ago. Any ideas or ways to narrow down the problem? Thank you in advance

 

[jeff4912]

The rear differential has a friction modifier in it that can dissipate over time and cause the rear end to make the grinding noise especially at slow speed and sharp turns.

My did this and I changed the rear differential fluid and added the friction modifier and the problem was solved.

 

[jhbpilot]

Ok thanks for the tip! I will give that a try. I did it about 3 years and 30000 miles ago. Is this longer than I should have waited?

 

[jackrussell]

Another bad rear wheel bearing?
If you DO NOT have limited slip rear differential, check one side at a time by jacking up and running in gear to listen for bearing noise on the raised axle end. Be sure to block the other three wheels on the ground.