I recently installed a 3" leveling kit on my 07 f150. I removed the factory blocks and installed 3" steel blocks. Since then when I accelerate from a dead stop there is a knocking noise seems to be coming from the rear end. I check the torque on the ubolts, the universal joints, don't know what else to check. Anybody have any suggestions?

 

your pinion is off, i am pretty sure that is what it is.

 

Not to sound dumb but how do you fix that?

 

When you replaced the rear blocks, Did they have the alighnment ***** like these? http://store.fatbobsgarage.com/share...t=products.asp
Or were they just standard lift blocks? Those ***** help align the rear end.

 

Thats where I got the lift from Fat Bobs Garage?

 

then if the ***** were aligned, you should be fine on pinion. did you check stuff like upper shock bolts, shackle bolts, or something small as spare tire tight? ( i know it sounds dumb)

you said it comes from the back. but could it be in front. the 3" level is maxing angles up front and the upper control arm is barely off the coil springs. when you accelerate it could lift the front and knock the upper control arm on the coil. just a thought.

 

Sounds like it may be axle wrap, This thread may help...
https://www.f150online.com/forums/su...axle-wrap.html

 

Those are all good ideas. I will start checking all of them this weekend. Thanks Anything else you can think of let me know.