steve14

I have 2005 f150 fX4 when I go to accelerate from a dead stop
I get a vibrating shuttering from the back tires . I oringinally thought it
was due to the tires but I just put on brand new BFG Rugged Trail and it
actualy even seems like its gotten worse. I have no idea if this a transmission problem or a rear differential , it almost feels like its starting in the wrong gear thats the type of vibration . It doesnt happen all the time on and off .It seems like it gets worse as the truck is warmer or I
have been driving it for a while not sure

anybody know what this could be would be a great help thank you

atvrider93

sounds a little like your tranny is starting to slip
how many miles, etc?

steve14

I have approx. 86 000 miles , the vibration only lasts for a second

dukesaskatoon

Don't know if you figured it out or not but I had a similar problem it ended up being in the rear end the pinion nut that forces the yolk against the crush sleve came loose. You can tell by wiggling the yolk and looking for oil leakage from the front of the diffy.

red06

dukesaskatoon, what ended up being the fix for that?

steve14

Well I ended up having the oil changed in the rear diff and also
an additive was added thats recomended buy ford guess they are aware
of the problem but not doing about it. Its chattering of the clutches in the
rear diff , it went away for about 3 weeks since then but its back again now but not as bad . I am very disappointed in this Ford truck....