Low pulsing hum felt in pedals and steering wheel in 2015 DCSB SR5 4x4.

I mostly feel this at low speeds, 25mph or lower. I cannot tell if it goes away above that or I am just unable to hear it over the road noise. Its about a 1 second pulse of a hum followed by about 1 second of nothing. I have jacked up the front and shaken the shit out of the wheels to check for wheel bearings, no play. Changed the front diff fluid and greased the driveshaft, no change. Recently there has been a grease leak from the drivers side CV boot at the wheel. Truck drives smooth and quiet on the highway. I have to drive it from New York to California next month, so I'm trying to get it in tip-top shape. 160,000 miles, no towing or off-roading, 4wd used primarily in winter up here on snowy and icy roads.

 

I’ve never been able to get any play out of a failing wheel bearing in these trucks.
You have to spin the wheel and feel it at knuckle or tie rod. If it has play is it WORN FLAT OUT.

In my experience these bearing go through vibration and noise stages as the wear progresses. Easiest give away is if the noise changes when turning.

If you want to see if it’s the needle bearing in the front. See if noise goes away in 4WD.

And don’t think a bad rear wheel bearing can’t mimic a front. It can sometimes.

 

Does it happen while turning corners? Might be that Trac control issue that gets fixed with a recalibration

 

Should see a Traction Light flashing when it's happening if that's the case but good point.

 

Sometimes people don't look down

 

Or they look down, see the christmas tree, and ignore it until it just won't go anymore

 

I had a pulse exactly as you described that I could feel in my pedal, I felt it at 35-55 but I also have 34" tires so the harmonics would be different from yours.

My educated guess is it's your wheel bearings as replacing mine fixed it.

I recommend @05Taco4x4 's "press service".

 

I have the same pulsing vibe felt in the pedals and through the floor at 35-40 as well as 65-70. I have 44k. Also happens (worse) when turning when slower (25-30). Haven't thrown any parts at it but haven't been able to figure out what it could be.

 

It does indeed happen while turning

 

Next time you feel it, look down and see if the Trac light is flashing

 

Never got a light, but I will pay attention to it

 

Or only look down at a phone til they wreck.

 

You could try the recalibration and see if it helps. There's a link around here somewhere

I've always done it with a scan tool but pretty sure there's another way

 

Actually I guess it's VSC (vehicle stability control) not Trac. But try it anyway

https://www.tacomaworld.com/threads...ibrate-your-vsc-computer-the-easy-way.467485/

 

Some other threads on the forum led me to diagnose the needle bearing (and you guys in this thread as well, thank you). The maintenance doesn't look bad at all to fix. Question now, should I do this before the cross country drive, or is it safe to leave for when I arrive in California? What can go wrong?

 

I drove on mine for over a year.
I am not saying that’s what you should do, but I did. Not necessarily on purpose.
Procrastination and gathering tools to do it was the biggest reason.

 

Are you stock height? I have the 3rd gen suspension so I guess I'm +1 in the front but had felt it before I did that. Kind of always put the needle bearing to the side because of the fact that I'm not lifted...

 

I am not lifted, truck is stock height. The most aggressive thing I have done is put Bilstein 4600's on it....

 

My truck is stock. My needle bearing want bad. It’s not common, but it can happen to stock trucks.

Some will probably say it was because I didn’t change the diff fluid soon enough.
Who knows? I know plenty of guys that have never changed their diff fluid and their needle bearing is fine.

 

The truck has 160k on it, so things are bound to start going bad. Its been pretty bulletproof, so I can't complain. Its fun to turn a wrench every once in a while....