Chasing that Tacoma Drone

2015 DCLB 4x4 4.0. Stock (afaik), 70,000 miles

New owner here, had it for about 2000 miles. Been reading all the forums on similar sounds but it seems like a tossup on Hub/CV/Tires, other things... Been scratching my head about some humming/droning that occurs between 20-45 mph. Most noticable at the lower end of that where road noise is minimal. It's kinda non descript, but is mostly uniform and doesn't have a rhythm. The pitch increases in that speed range.

I did a hub job today, all new with new seals, absolutely no change.

It does not change with RPM or gear.

It does not change with 4x4 selection.

Upon replacing the hubs today, the stock CVs seemed ok. No harsh clicks or sounds. The truck turns and drives from lock to lock without incident.

There is no play in the front end.

The truck has Motomaster Total Terrain AT/3s with 8/32" at all four corners. As an aside, I do not like these tires for snow performance.

The (incomplete) service records from the previous owner do not indicate anything out of the ordinary. The only thing of note is as follows: "CUSTOMER DECLINED THE FOLLOWING DEALER RECOMMENDATIONS~~4X4 SERVICE $274.95"

So... My question is of course. What the heck is this droning? Not front hubs. Tires? Could it be something in the T-case related to the declined service? Does the T-case just need a fluid change?

My next thought is to jack stand the rear and spin up to 20mph...

 

Does the noise exist in 4H? Could be a front differential bearing... although with no lift and low mileage perhaps not. Lots of info on this forum about front differential bearings and ECGS bushings.

 

I read all about ECGS. There is no change in 4wd

 

I purchased my 2010 with almost 41,000 miles on it and it came with new Cooper Discoverer HTPs. In October 2022 I purchased some Toyo A31 Open Countries take-offs from Craigslist off of a 2022 truck with something like 261 miles on them. There was a considerable difference in road noise between the tires and the stock Toyo tires are noticeably quieter than the Coopers.
It could be the tires.

 

Maybe your driveshaft carrier bearing? Just adding another thing to the list to check.

 

Fair point. It just doesn't... FEEL like tires in how the sound comes through the truck. MotoMasters are Coopers, and I've had ok luck with them in the past for noise, and longevity, just not snow...

It's def on the list tho..

 

Oh man, I hope it's not this one.

 

And ujoints and rear wheel bearings. I take it this humming was not present when you got the truck?

 

It sounds louder now, but maybe I just didn't notice it, all caught up in that new-to-me truck moment.

 

Few more questions:

- Does the noise change at all if you brake while it's happening?

- Can you feel anything in the steering wheel?

- Any noticeable change in sound with the windows down?

- Have you been able to figure out if the noise is from front/rear/left/right/center, or does it just come from everywhere?

The other option is to turn the radio up and keep driving

 

Braking, I am pretty sure no change. As I drive 25 down a steep hill, on the brakes and it's there.

I can't feel anything in the wheel but I can kinda maybe feel the sound in the gas pedal? Maybe? It's faint.

No change windows down.

Doesn't sound left or right... Which is why the driveshaft and rear might be my next investigation.

 

Update.

I jacked up one side of the truck at a time and put it in 4wd... Being open diffs I wanted to spin each wheel independently, as well as hear it without road noise and isolate sides.

No howl/drone at all...

Tires? Or is it simply something that's only gonna kick on under load?

 

U would feel the unbalanced driveshaft when stepping and releasing accelerator

 

The tires look nice and the lugs don't look aggressive enough to create a loud hum. Uneven wear pattern can be noisy. Do a tire rotation to see if the humming pitch changes.

 

Tires have been meh, 8/32" left and I'll probably ditch em. The rears may be a bit cupped? I'll rotate or something haha

 

Hey y'all, it was the tires.

Cupped, probably for lack of rotation by previous owner. And whatever quality Motomaster are...

Anyways, Falkens on 17s now! No drone. Perfect.