2012 fx4 5.0 about 202k on it. I get like a rear end bounce that goes away after 50mph. most predominant at 45mph. its like I have eggs for tires.

I rotated tires and persists so not tires? I dont think shocks as the Bounce test seems like they are ok. smooth road no change. wonder what causing the rear end to hop or bounce like that. like I say worst at 45 goes away at 50.

Thank you

if everyone thinks it may indeed be the bearing how diy freindly is this.....I pretty good with mechanics if I know what to do. Did a lead frame replacement recently. dropped the trans valve body that wasnt bad.

From reading other threads I think I am going to try new shock to rule them out 100% and its probably time to replace anyways......these have atleast 70k on em.

 

Got a brake dragging? Ive had that happen before when a caliper stuck, it would bounce and hop a bit, felt like an out of round tire.

 

if shocks are OEM, put a set of bilstein 5100s. Even if its not the culprit, id say 202k out of the OEM shocks is good enough.

 

Hmmm I have a front brake drag...I was going to ask about that too as its a new caliper...new guide pins...why is it dragging dammit?!

but again its the front........none in the rrear.......

This is the other thread that made me re-think shocks...as it exactly where I bounce the most 45

https://www.f150forum.com/f38/rear-e...-45mph-483486/

 

Is this on every road, or always over the same area?

 

every roaad every time. tried it on a newly paved road to be sure not roadway. I first figured a tire but after rotating I was like whaaa...

Just ordered new shocks for the rear.....we will see.......and will report back...no noises associated with it...just the bounce...

Thank you all.

now on to search my next issue.......

 

Just installed my Bilsteins Saturday. Night and day. Mine is a 2010 with 161K miles. Those shocks were just tired. Now it feels way more stable.

 

Put the rear on jack stands a run it gear to look for a bent axle.

 

I can see how a dragging brake could do that... i will check tonight.......thats good info to know the ears in the rears...hehehe

if that dont work I can check for bent axle but I dont think I loaded it or did anything to cause a bent axle.........but its all worth a check to solve the issue.

Thanks all

 

Same thing here. Dealer says it's a known problem and Ford sells a weight kit that they attach under the bed. I have no idea if it works.