“Wub wub wub” sound/feeling

When driving at around 20mph I have a faint “wub wub wub wub” sound and feeling in the floorboard that increases and decreases with speed. It does it with the brakes applied and without, as well as in drive and neutral, and in 4wd. I can’t figure out if it’s something that needs to be replaced or if it’s just a normal vibration that I haven’t tuned into until recently. It goes away above about 30 mph and drives really smooth on the highway.

The truck has stock 2016 3rd gen TRD OR suspension with about 40k on it now, brand new u-joints and carrier bearing (no change after replacement), newer brakes and rotors. Tires are in great shape and have been balanced twice in the last 10k miles. I have new wheel bearings but have not installed them yet as there is no play with wheels off the ground.

The only thing that makes me suspect wheel bearings at this point is that they are original with 176k on them and I get a slight hum around 50mph that sounds like wind noise in my roof rack, but maybe it’s a bearing humming?

Has anyone else experience this?

 

I have a similar feeling in my 4runner at 50MPH but I’m at 18,000 miles

 

Does the sound change or go away going into and out of curves?
or if you turn the steering wheel slight one direction while it is making the sound?

 

Sounds like wheel bearings. That’s exactly what my truck felt like before I got mine changed to the ECGS ones. Turned out my OEM bearings were shot.

 

Not that I have noticed but it’s very consistent about showing up around 50 mph and going away under that

 

Does it go away if you throw it in 4wd? Sounds like the needle bearing in the front differential.

Wheel bearing issue a good possibility as well, as mentioned above.

 

It is still there in 4wd

 

Not typically how wheel bearings fail.

I'd let it get worse, or find out for sure what it is, before throwing parts at it.

Does it do it if you are in 4th gear (Auto)?
Or a different gear in a manual trans....?

 

Maybe a tire or wheel rubbing against something under the truck?

 

I just drove around and tried putting it in 4 (it’s an auto) and the feeling was still there at 20ish mph and the noise was still there at 50mph+ as well. I would love to figure out what it is haha, I kind of already have thrown parts at it thinking I would eventually fix it with the carrier bearing and u-joints. I already have the wheel bearings in my shed so that may just be my next step to see if those fix it.

 

If you already have them, nothing to loose by throwing them on and seeing what happens.

 

2nd that. Bad wheel bearings will make noise that increases with the wheel speed, faster u go the louder it’ll be.

Possibly a harmonic vibration from something. You didn’t mention checking the rear diff. Good fluid in it at the right level?

 

What kind of tires and mileage?

I've had big block treaded tires make similar noise when they started feathering on the edges, and sound not be noticeable at speed.

 

Might just be the tires. That's my 1st guess.

 

they are Goodyear Ultraterrains with about 30k miles on them. They have been wearing very slowly and evenly though, and have been rotated/balanced twice in the last 10k miles.

 

That’s a good point. I changed my rear diff fluid about 10k ago but I haven’t checked it since, maybe I will craw under there and check a sample of the fluid and make sure level is good.

 

Well, that is a big block tire. And you've cared for them with rotations and balance, but how about alignments?

Got a friend with a Tacoma and more of a 'street tire'? Work with them to put their wheels on your truck just long enough for you to 'test' and see if the noise ends or changes. It's a bit of effort, but cheaper than buying new tires or firing the parts cannon when you're not sure what the target really is.

 

Knowing this I’m gonna say it’s tires, especially at only 1 speed range. Because of the block size it’s not uncommon even if well maintained. I previously owned a Hummer H3 on 35” mud tires and this would happen between 50-60 with even tire wear and rebalancing/rotating every year. For me at was also noticeable when slowing to a stop, maybe ~5mph down to being stopped, though my tread pattern was more aggressive than yours.

When you pull up to a stoplight do you experience noise or vibration?

 

I haven’t noticed any noise or vibration coming to a stop, just the wub wub slowing down as I slow down. The tires don’t sound noisy like how some mud tires hum on pavement. There’s not really any noise at the 20-30 mph range when the wubwub starts it’s more just a feeling. But I see how one block slightly out of place could cause what I’m feeling.

Also alignments have been fine, it’s gotten 3 alignments over the last 8 years and has always tracked straight with even tire wear.

 

Yeah I’m gonna say it’s a harmonic effect of the tire lugs/blocks. Maybe someone else with an aggressive off-road tire can weigh in??

FWIW I noticed with my old rig that it was more pronounced when the tires were new, after each tire rotation it would be more noticeable but fade over time as the tire lugs started to wear the leading edge down after putting some miles on. (When rotating tires side to side) hope this makes sense.

again, I’m no expert, just what I noticed in my own experiences…