Bruce3966

So after I purchased my 2007 F150, I noticed a small vibration when turning fast off a dead stop. I used to forum to see that others suggested to replace the rear pumpkin fluid and add anti-friction to the fluid it so I did and boom, it went totally away within a week however, now it's back. It's been about a year and a half since I replaced the fluid and added the anti-friction stuff.

Is this normal or should that have lasted longer

Angus1

Same thing on my 06. The rear dif started to chatter around 150k. I used royal purple with modifier built in plus added some modifier. I'd get about 15,000 miles and have to do it again. Something to consider, when my ball joints went it was almost the exact same feeling. I guess my point is, change the dif oil. If that doesn't fix it check the ball joints.

Summers22

iTrader: (2)

Sounds just like mine. I changed my rear diff fluid at 140K, at 160K some slippage started to happen, but only on hard acceleration from a stop. I drained 4 oz. of fluid and added another bottle of Motorcraft XL3 and it cured it. So my suggestion is to do what I did. For $7 its worth a try.