I found a flat piece of pavement and drove it in 4HI and the sound and vibration are still present.

Thanks for this. I found some flat pavement to test out and the noise and steering wheel vibration are still present so according to this document it is not the front differential.

No particular reference, just my process through the years of working one end to the other. I deal with a lot of electrical and controls systems at work and we always test every point through process of elimination. Whenever you skip something that it "cannot" be, that is usually the problem.

That being said the needle bearing issue sounds plausible.

I took it out onto a flat road today and ran it in 4HI but the problem with the steering wheel shake and the distant thumping sound is still there.

Do you think it might be a wheel hub issue? It's the last of the rotational parts I can think of.

Your gonna have to do some major MacGyver type trouble shooting.
Not sure of the answer, but some things to test to MAYBE help find the issue...
I would be doing every "test" I can think of and write down the results. As an example.
1 when it wobbles, downshift and maintain same speed....does change anything?
2. Does the wobble frequency change with speed changes?
3. What happens if you shift into neutral and coast?
4. Have jacked up the front and spun the wheel by hand and listened. Touch an automotive stethoscope to hubs and see if both sides sound the same?
5. Check runout on wheels with dial indicator while up on stand.
6. Are all balljoints tight and not worn out.
7. Could be the hubs/bearings, even though you can't feel by tugging on wheel.

You sure did. I forgot your list on my way scrolling down.

Crack the diffs open and check for missing teeth? Lol


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1 when it wobbles, downshift and maintain same speed....does change anything?

-No. I have done every imaginable scenario from slow / fast acceleration / braking / downshift. Nothing changes. What's even stranger is the wobble / noise will be present while driving then I come to a stop at a light then begin acceleration and the wobble / sound goes away then will randomly start back up for no apparent reason or change in driving style.


2. Does the wobble frequency change with speed changes?

- No. As mentioned in previous question I have run every possible scenario and cannot find anything I can peg the occurrence to.


3. What happens if you shift into neutral and coast?

- Same issues.


4. Have jacked up the front and spun the wheel by hand and listened. Touch an automotive stethoscope to hubs and see if both sides sound the same?

- Did this a few weeks back before I replaced pads, rotors, and CV axles. I did not use an automotive stethoscope on the hubs but I did rotate them to see if I could feel or hear any noise at all and I could not hear a thing. The wheel was very tight on the hub as well.


5. Check runout on wheels with dial indicator while up on stand.

- We did this when I changed out new wheels and tires a couple weeks back.


6. Are all balljoints tight and not worn out.

- Yes, tight and definitely no where close to being worn out. Admittedly, I wheel, however, the area I wheel is not rocky terrain and is more steep hill climbs, deep sand, and mostly moderate to difficult trail features but no rocks.


7. Could be the hubs/bearings, even though you can't feel by tugging on wheel.

- As crazy as it sounds this is what my intuition has told me from the beginning. I was on the fence about replacing the CV axles and waffled between those and replacing the wheel hubs. The only reason I didn't go wheel hubs first was how tight everything was and I couldn't hear anything that sounded concerning.

I guess I am going to pull the trigger and order the wheel hubs tomorrow and find the time next week to do this.

I appreciate all the help you've offered. It's been a big help believe it or not.

One last question. This is the first time I've dealt with wheel hubs. In the past I've only worked with wheel bearings. I've replaced wheel bearings in the past based off of the usual and customary tell tale signs. Is there something different with a wheel hub that makes it more difficult to diagnose than traditional wheel bearings?

One more thought: Check the brake discs for warp. (take the wheel off, and while spinning the disc, hold the edge of a screw driver next to the disc).

I had a strange issue with the brake disc on my RAV4: there was a casting imperfection that caused one spot on the disc to be much harder than the rest of the disc, so, over time, it developed a lump there, i.e. the disc was thicker where the lump was. Took me forever to discover that.

I just installed brand new OEM brake pads. I even put a level against them in advance even though the issue was there before I installed the new pads. Same with the rotors. All level surfaces.

the noise has me scratching my head a bit.. have you ever greased your driveshaft?

for the wobble--how hard have you wheeled it? my wobble issue was eventually solved by replacing my lower control arms. my bushings were shot enough that new tires, wheels, etc., and tons of road force balancing wouldn't resolve the issue. visually they looked fine...but they were not.

When I say "noise" I mean it is a distant sound of a repetitive thump as if something is stuck in the tire. You can feel the thump in the steering wheel while it wobbles slightly.

The issue existed before I ever wheeled it and even when I do wheel I do not do anything extreme where I am seriously taxing the suspension. However, and to your point I have checked all suspension areas to make sure there was no damage.

I've placed 3 sets of tires on this rig and all were road forced and the problem still persists.

Your post ultimately led me to discover this issue.

Check this out. How the hell did this pass Toyota QA?

https://www.youtube.com/watch?v=BOvoM5irtEc

I'm still narrowing down the cause but discovered this video yesterday and just got back from the shop where we put the truck up on the rack. The play in my driver's side CV axle is ridiculous.

How the hell this part passed Toyota QA is beyond me. I have the bushing on order and will install it next week. Hopefully this will resolve the issue.

Thought you might find this interesting: https://www.youtube.com/watch?v=BOvoM5irtEc

Hmmm interesting.....your CV....Is it a OE part or aftermarket?

Both CV axles I replaced are OE.

A little more research on this topic turned up this thread about this very topic and it also discusses the TSB. Sounds like the bushing will be a permanent fix.

Needle bearing issue? | Toyota 4Runner Forum [4Runners.com]