rear noise rear end "thump" noise in sync with vehicle speed

[thesavo]

This is a 2014 Edge 3.5L SEL AWD with 161,000 miles. 

 

For the past few weeks we now there has been a "thump" noise that is in sync with vehicle speed.  I can upload a video of the noise, but is is the sound of "thump","thump"-"thump"-"thump and gets faster with an increase in vehicle speeds up to highway speeds.  We were late in to a road-trip when it started.   We had a tire-shop rebalance the tires, no change in noise and frequency. 

 

 The inward pad on the driver side was worn almost down to backing of the pad.  The passenger side seemed to have even wear, however the piston was equally difficult to react as the driver and boot was torn up. 

 

I changed the rear calipers.  The calipers were targeted as they needed an extreme amount of torque to spin the piston back into the caliper.  I tried to bleeder trick to determine if it was a bad caliper or brake hose, by pumping up the peddle 4 times and cracking open the bleeder screws.  They only dribbled out and I still needed way too much torque to spin the pistons back in.  

 

Now, having replaced the calipers, the brakes work fine, however the parking brake doesn't seem to hold as well.  I'll work on that in another thread.  The passenger side holds better than the driver side. 

 

The "thump" noise is still present while driving as slow as 2-3 miles per hour.  

 

 

There is no left-to-right or up-to-down movement when shaking the tires on either side.

 

Before I reload the parts cannon with rear-wheel bearings, what further troubleshooting should I try next?

 

 

Edited 38 minutes ago by thesavo
grammar