Momentary howl and pull to the right on interstate

I have a 2011 PreRunner V6 that has just hit 210k miles. I bought it in 2017 with 118k miles. Today on the interstate, I was doing somewhere between 70 and 80 when it started making some intermittent howling noises. The noises would last a fraction of a second each time, and the truck pulled pretty firmly to the right. I slowed down to about 65 and stopped hearing it, and wondered if it might have just been some very strong wind, but I'd never experienced that particular type of noise before just from wind. I pulled over at a gas station and got out to check for anything obvious, but found nothing. So I got back on the interstate and tried to reproduce the sound by driving 70-80, but didn't hear it again the rest of the way home.

I should probably mention that about 20-30k miles ago, I changed the rear brakes and axle seals. While draining the differential fluid, there was at least one good-sized metal shard on the drain plug. Am I safe to assume what I'm experiencing could be symptoms of a failing differential?

 

Possibly but usually things like that aren't intermittent. Sounds more like mabe VSC kicking in when it shouldnt be, did you notice any lights blinking on your dash?

 

Or he may have a wheel bearing issue...

 

No, this was definitely not that. Mine makes a beeping sound when it kicks in. This definitely originated from outside the cabin and was a completely different noise. My thoughts when initially hearing the sound were that a tire was rubbing on something (since it would pull to the right). It was a low-pitched and momentary, halfway between a chirp and a howl.

 

When it first happened, I was like "God, I hope it's not my wheel bearings." Now, I'm like "God, I hope it's just my wheel bearings."

 

this happens to me, it's an aggressive wind howling between the mirror and the window frame as best i can guess. usually happens on my passenger side when it hits the right angle on particularly cross-windy days. lasts no more than a second and usually happens in sporadic bursts of 2-3 howls and then nothing for a while.

eta: a wheel bearing, from my experience with a ford escape, is that it sounds like your car has a front propeller and is trying to take off

 

There's a tsb for the whistle noise in a strong crosswind, I think it involves replacing the weatherstripping around the front doors. Mine does it sometimes on a windy day but it's not bad enough for me to worry about it.
Have to raise the wheels off the ground and check your bearings for play and/or noise.

 

According to Toyota the diff oil gets changed every 30k miles. You could check the magnet again while you're in there, just to rule that out. I would wonder about wheel bearings myself. It seems like the most common sign of failure on these trucks is more of a constant sound though, not so much what you described.

 

I'm past due on tire rotation, so I guess I'll do that soon and check the bearings. If it was in fact just noise from wind, that was a hell of a crosswind. But my inner optimist isn't ruling that out.

Last time I was at the dealer, I asked what the cost of replacing the differential was. The guy told me they don't do just differentials, and that they'd replace the whole rear end. I'm wondering if I should just go ahead and trade the truck before it does go out, or if there's a cheaper long-term solution.

 

Sure sounds like wind to me.

I've never heard of a truck suddenly pulling to the right, intermittently on and off. Either your power steering has a demon or it's a crosswind. I could be wrong, so don't take my word for it.

These trucks are shaped like a brick. It doesn't take much wind to pull on it when you're going 80.