Correlation between “diff howl” and air dam removal?

i get exhaust resonance noises at certain speeds/rpms that sound like diff howl. it's more of a ringing noise than a whine though.

 

I wonder about exhaust noise to cryptolime.

Like most of you, I’ve driven a lot of vehicles in my day. All of them used and older. This is the 1st new vehicle I’ve ever owned. After 28k miles and 40k$$$, I’m just trying to understand why and how certain noises occur. Some, no big deal. Others I’d like to try and troubleshoot/solve.

Just trying to understand my personal investment more. That being said, love the truck and no regrets so far.

 

I've never noticed wind noise or diff howl on my 2nd gen. I'd associate diff howl to poor engineering and taco lean that was never corrected before the 2nd gen 1st went into production. The truck isn't balanced, not a real issue or concern as Toyota has been successfully selling these trucks for close to two decades now. There is a cause to what ever noises these trucks make.

I never really notice wind noise on any vehicles ourside of bad door and window seals, or an open moonroof. I do notice wind noise when there is more wind. I've never subscribed to the idea that vehicles are supposed to be silent when traveling down the highway.

 

there is plenty of discussion about diff howl. I have a ‘21 OR. Changed diff fluid at 1K. Still have a slight whine around 55mph and feathering the throttle. I didn’t follow the forum recommended diff break in of drive, let cool down, then drive, cool down, etc. I just went for it from the dealer 300 mi away. Oh well, I’m sure this truck will last many many miles and the diff howl is not a concern to me.

 

I’ll add the following as a cautionary tale about our rear diffs;

Several months ago I posted about this. But one day at about 15k miles I decided to check rear diff oil level. Parked in level parking lot, I opened up the fill plug and felt NO oil with my finger! Ended up adding about 1.5qts of gear oil. Wish I had checked it many miles earlier. So far, diff runs fine.