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 Saturday at 09:44 PM by thesavo
grammar

[Samurai Edge]

Your  " thump","thump"-"thump"-"thump "  sound is a rotational noise, as opposed to something loose banging.

 

Possible options:

 - Something with the drive shaft.  Could have a worn bearing

  - Something with a tire.  I know you said you had them re-balanced, but could have belt separation.  How many miles on the tires?

 

Those are the first two things I would consider.

 

You also didn't say where the noise was coming from?   Front, Rear, Right Side, Left Side?

 

 

[thesavo]

Thank you Samurai Edge for your response.  The sound did emanate from the rear of the vehicle, though pin-pointing to one side or the other was in conclusive. The tires are only 2 years old with no visual signs undue wear.   A nail what noticed in one threads, however this discovery was minimized by a shade-tree mechanical member of the family as "being  beneath the death of thread" as the sound can be heard starting at such low speeds. 

 

So on Sunday, I made a failed-attempt to unbolt the wheel bearing from the knuckle and isolate it from the drive-shaft non-destructively.

To make a long story short, this did not workout. 

 

A 55-ton press was required to remove the (bolt-on) wheel bearing as attempts with traditional slide hammers and hub pullers lead to another failed attempt with the an Orion puller. 
https://a.co/d/09GzRjxl

 

New wheel bearings are on order from Detroit-axle which has been a good brand of brake and suspension parts in the past.

 

 

[1004ron]

@thesavo I may have missed it, but did you confirm that the wheel bearing was bad once it was removed?

[thesavo]

Sadly as another friend was called in to assist,  the passenger side bearing we started on was not in a trustworthy state of being tested. 

 

Through I will say we didn't impart the same force on the driver side bearing as we were able to remove all the remaining bolts to remove the knuckle.   It did have some drag while trying to spin. 

 

As a note. There is special tool to separate the knuckle from the control arm.  Though do remember to loosely re-install the nut on the joint connecting the knuckle to the control arm before using the press, or you will need an angle-grinder to repair the threads. 

If anyone else is attempting this in the salt-belt, I would advise to remove the knuckle completely and use the services of a machine shop to press the bolt-on bearing from the knuckle.  It doesn't separate as easy as many youtube videos would have you believe.

 

I will be making use of silver never-seize when installing the replacement bearings. 

 

Video removal

https://youtu.be/8lpb7_TarU4?is=eMjgVEoQMRU1bhlA

 

Special tool

https://shop.advanceautoparts.com/p/performance-tool-ford-ball-joint-separator-low-profile-w83051/50159995

Edited 1 hour ago by thesavo

[Samurai Edge]

I have found that TRQ makes good videos.  Informative and easy to understand.

 

And, yes, I already have that removal tool, and others.  They work really well.