Thumping sound driving me crazy

[NJayL]

Hello everyone. I'm new to the forum and would like to introduce myself real quick. I'm a U.S. Marine that in his spare time likes to work on vehicles. I'm not particularly gifted at it like some of you are, but I find it enjoyable. I feel a tad bad introducing myself at the same time as asking for advice, but my Explorer (2010 XLT 4.0 4x4) has been having a problem that has me flat-out stumped.

For the past few months it has been making a strange thumping sound from the front left wheel. It's not a clicking sound like bad CV joints would make, or a knocking sound, but a rotational thumping noise and increases with vehicle speed. It has gotten worse with time, but very slowly.

Here's what a I've done so far:
-I checked the tire for cupping. Tire was as smooth as ever.
-I rotated the tires. The sound remained.
-I checked the ball joints and tie-rods for tightness; no issues.
-I popped out the front left half shaft, plugged the hole, and drove around the block. The sound remained.
-I changed the driver front hub & bearing assembly (and did the passenger front for good measure), and the sound remained.

At this point, I'm stumped. I guess it could be the struts, but I replaced those two years ago with Monroe units and they still look fine. Any advice would be greatly appreciated!

 

[Mbrooks420]

Pull the front driveshaft.

 

[NJayL]

Hi Mbrooks420. I did pull the shaft and drove around a bit, but the sound remained and didn't change.

 

[Mbrooks420]

Oh, I thought you only pulled the half shaft. Might be differential related then. Not much else it could be.

 

[NJayL]

My bad, yep, I did only pull the one half shaft. So you think I should try pulling the whole axle?

 

[07EddyB]

He is saying since it is a 4x4 pull the front driveshaft - not the half shafts to the wheels. The shaft from the transfer case to the front diff. It runs on that side so could be your problem.

 

[NJayL]

Ah, got it. I'll try that. Thanks for the clarification.

 

[michael loibl]

And if that doesn’t make the noise stop, I’d try pulling the other half shaft out also, and see if there is any noise with all 3 front shafts out

 

[NJayL]

Hi guys. Thanks for all the advice thus far.
So I pulled the two axles and front drive shaft this morning and took it for a drive. Sound was still there. At this point, I suspect it might be something totally simple that I'm just missing. I'm thinking about just letting it get worse so it's easier to diagnose.

 

[07EddyB]

At this point it has to be in the wheel or the brakes. You rotated the tires so I would be looking at the brakes.

 

[F SANE IL]

Any success? I've got a similar situation and can't figure it out for the life of me.. My noise seems to be worse when I put pressure on the steering wheel as i drive. Right of left, doesn't matter, the rotating wawawawawawa gets worse. I've not pulled the CV on either side nor the D-shaft to the front. Going to try based on this thread.

 

[NJayL]

Hello everyone. So here's an update on my sound.....it ended up being the passenger-side rear wheel bearing! Apparently it was so bad that the vibrations/noise were traveling up the vehicle and manifesting as a "whump whump whump" from the driver front wheel. Figured it out by putting it on a lift, taking the traction control off, putting it in 4x4 and 1st gear, and having someone accelerate to 30mph or so, and then listening with a stethoscope to each wheel. Who woulda thought?! Now, after replacing it, the sound has gone away.

Thanks for y'all's advice!

F Sane Il, sorry for the late reply. Any luck so far with the sound?

 

[07EddyB]

Interesting. Did you ever feel a vibration in your steering wheel that was speed dependent? I have had that and it turned out to be a rear bearing. At around 70 I was getting a pretty good shake in the steering wheel. Knowing that the front bearings were fairly fresh and that the rears were at 100K I took a chance on the passenger rear. Here was my post from back then:
"From 65 to 75 my steering wheel would shake and I could hear a roar. I drove it for a few months more until I finally got the noise to change when turning. It was a right side bearing. Considering that my right front was fairly new and my right rear was OEM I went ahead and replaced the rear one. That took care of the problem. I was shocked that you could feel a rear bearing in the steering wheel that bad. Had my front bearing been old I would have started there."
Since you didn't mention any shake in the steering I didn't mention it. Glad you got it figured out.

 

[F SANE IL]

Hello everyone. So here's an update on my sound.....it ended up being the passenger-side rear wheel bearing! Apparently it was so bad that the vibrations/noise were traveling up the vehicle and manifesting as a "whump whump whump" from the driver front wheel. Figured it out by putting it on a lift, taking the traction control off, putting it in 4x4 and 1st gear, and having someone accelerate to 30mph or so, and then listening with a stethoscope to each wheel. Who woulda thought?! Now, after replacing it, the sound has gone away.

Thanks for y'all's advice!

F Sane Il, sorry for the late reply. Any luck so far with the sound?

No, still have it. I had some guests come over from abroad, went to get them from airport and thermostat bypass hose blew up, overheated. Fixed the hose and added coolant to drive home, but there was air in system. They just left and I finally got air out. Getting back to the noise next week.

I've watched dozens of YouTube videos and I think it's either driveshaft, cv, or front diff. But after reading this, maybe I should check rear hubs. Both front are pretty new. Maybe 5k miles on them.

 

[NJayL]

Strangely enough, I never felt a vibration in my steering wheel. I swore I could feel a vibration in my left foot though!

 

[F SANE IL]

Strangely enough, I never felt a vibration in my steering wheel. I swore I could feel a vibration in my left foot though!

I'm thinking mine might be drive shaft or CVs. Or maybe the diff. Only because it's more like a rotating sound. I've had a bad hub in past and it was a constant sound like waaaaay. This on is more like wa wa wa wa wa.

 

[NJayL]

That's what I thought too. The last hub I had that was bad made the classic sound you described. This time though, I could have swore the sound was coming from the front. I could feel it in my foot and hear it. Yet when I replaced the rear bearing, the sound went away.

 

[F SANE IL]

I got mine done!!!

In the end it was the driver side hub and as a bonus, the lower ball joint.

When i did the usual check, by shaking tire at 9 and 3, then at 12 and 6 - nothing shook. I did notice a completely torn up sway link and replaced it after I tried to shake things around and didn't find anything at that point. However, once I took off the wheel, caliper and rotor, i was able to move the whole spindle up/down about 1/8" it looked like the nut on the ball joint wasn't screwed in all the way, but it was fully in actually. I replaced the ball joint and decided to take out the hub since I was in there. Turning the hub while it was on the spindle felt possibly rough, but didn't make any noise nor did the hub shake at all. After taking the hub off the spindle, turning it in my hands i could feel the grinding of the bearings within. Of course the sway link was messed up bad due to the spindle walking up/down the way it did.

Now with the hub all fresh, new ball joint and link tightened, it drives like new.

Parts: I decided to get the hub from Autozone, cost me $209 i believe and comes with 2 year warranty which i'm planning on using. Lower ball joint i got was the Valucraft for $26.99, it has ridges on it all around so when you install it into the A-Arm using the press tool, it will sit in its designated spot tightly. Don't get the Duralast ball joint as I tried to use it and it was too small in diameter and falls right through the hole on the A-Arm. As I mentioned in some other post, if you need sway links, get them from AutoZone as they are lifetime warrantied. I'm sure lifetime warranty is nothing for a 3 yo car since parts rarely brake there. With an older vehicle though, if one part in suspension goes, it may affect other parts including ones you've recently changed.

 

[NJayL]

Nice! I'm glad you figured it out! And thanks for all the good info about parts. That's going to useful, as I'm sure the replacement of those parts will be on my agenda soon enough!