Reducing roof rack noise (Front Runner Slimline w/wind guard)

Hey all, I've been searching around this forum and others and can't seem to find anything to help me out. Hoping someone here can point me in the right direction!

A little while back I installed the Front Runner Slimsport on my 2019 Tacoma TRD Off Road (4 door cab). Install and everything went super smooth, and I do have the proper wind guard on it and no light bar.

Here's what I'm facing when the wind speed reaches about 80MPH (including if I'm doing 65/70MPH with strong winds). Usually there is first is a loud deep hum which quickly turns into intense vibration through the whole cab which is very loud and concerning. I totally understand racks and accessories up there will cause noise, and I accept that. But this isn't just wind noise, it's as if the rack is loose and the vibration genuinely feels violent at those higher wind speeds. Everything is tight and solid, triple checked. I do have a couple small boxes mounted on the rack, as well as traction boards but even when I take those off the sound & vibration persist in those same conditions.

I did leave a small (1cm-ish) gap between the bottom of the wind guard and the roof to prevent it from rubbing on the paint as per the instructions. Could this be causing the issue with air getting up under the wind guard causing it to vibrate? I could see that being a thing but followed the instructions very closely along with several install videos online. Also, kinda strange, the vibration and sound appear to be coming from the passenger side more than the driver side. It tends to scare passengers when it happens unexpectedly from gusts of wind or when accelerating (that's to say without the initial humming which has become my warning sign it's about to vibrate).

Unless there's a way to prevent paint rub, I would like to avoid having the wind guard touching the top of the cab. Happy to post pics if that'd be helpful, in fact may just snap a couple after work and add them - but maybe someone else has run into this and found a solution. Appreciate any advice!

Edit: I should mention this has been happening since the install. Took some time for me to notice it because I don't drive at highway speeds all that often

Edit 2: Adding some photos

 

Adding some rubber door edge trim might help, minor adjustments might help, going 80 mph with a roof rack isn’t going to be silent. I have Martin off road racks on my cab and cap and I get an occasional vibration hum when I get up around 80 or over which is rare because I’m getting about 12 mpg at that point.

 

Thanks for the reply! I did put the rubber trim along the bottom edge which came with the rack - is that what you're referencing? And yea totally understand it won't be silent, and I absolutely expect there to be noise. The best way I can describe it would be like the noise blades on a prop engine plane make, but a bit slower tempo and lower frequency/tone.

 

See the pics now, that rubber molding is what I was referring to with door edge guard.Messing with the adjustment on the wind deflector (closer, further, angle) might yield some results, but again with essentially a giant ladder bolted to the roof, there’s going to be both noise and reduced fuel economy. As mentioned, I get an annoying vibe around 80 mph too, it’s fine up until that point then the resonance or whatever is perfect. That’s my reminder to slow down a bit cause they are just really inefficient at that speed in terms of fuel consumption. It won’t do it if your drafting behind a big fast moving truck though, so there’s that!

 

I don't think there's anything you can do to avoid it.

At just the right speed, with just the right crosswind, going just the right direction...they'll all hum and vibrate.

Speed up, slow down or change lanes and draft behind a semi is about all you can do.

 

Gotcha, thanks friends! Yea I'm not much of a speedster, did enough of that when I was a teen and got caught plenty of times. Sometimes it's annoying having to go slower on the 75MPH speed limits here in CO but better than the racket that happens going too fast.

I didn't realize I could play with the angle of it? Seems like that may require some serious man handling with that metal & the thicker bracket on the back side. I can definitely try dropping it down a little closer, but as you can see it's pretty close on the ends already so I'm afraid if it is vibrating downwards it may end up rubbing up on the paint even if it's got space while standing still. Wish I had an audio for y'all, or that I could hear what others are experiencing to compare against because it is really loud and alarming - I can blast music to the limit and still hear that vibration over the music.

Totally get that, and those exact words have come out of my mouth when explaining this to people. It's definitely those "perfect storm" conditions

 

This guy has me wondering if that itty bitty amount of the front-most crossbar sitting above the wind guard is what's vibrating. Was just watching this video where he explained it and found a fix. It's a different rack, and his "before" was a much more significant height difference. https://www.youtube.com/watch?v=LkxXxgFqH-w

 

I have a different rack so I am not sure how much you can tweak the angle. You do want it close to the roof. I had mine really close and there was a minor rub mark but barely noticeable, so I just moved it up slightly and kind of tweaked the angle flexing it and tightened it back up. No matter what there will be noise during certain conditions but mine was noisier during all driving conditions until I messed with it a few times trying things out. Worth the utility though, I use mine all the time for carrying everything from kayaks to long and heavy lumber. Just be careful with the rachet straps, I've bent my lateral frames a few times and then have to bend them back.

 

I have a slimline 2 on my topper, with the factory wind fairings. I had loud harmonic noises until I moved the fairings apart several inches.

 

I have the slimline 2 with the fairing. I almost opted for your model but decided against it for being so new and no real reviews on it. Before that I had a prinsu which is basically the same design.
I would get the prinsu rubber edge trim and use that instead of the front runner one.
You can either, move the fairing really close to the roof with the prinsu trim or use a strip of PPF (like the one that comes with the front runner slimline fairing) and make the weatherstrip sit flush with the roof and u won’t need to worry about paint rub.
The 2nd option greatly reduced noise and vibrations on the prinsu for me, especially here in SoCal where we get really windy areas on the highway near Palm Springs. You will still get wind noise but vibration is a no go.
FYI, with the slimline 2 and the full fairing sitting flush to the roof, absolutely zero wind noise or vibration even up to 85mph. That’s with front runner wolf packs up there and an ikamper skycamp. That goes for the taco and 4Runner.

 

I have the same rack on my 2015 taco dcsb TRD OR. This is my second Frontrunner roof rack (first was on a 2020 gladiator) and both have been poor quality, design, fitment and the customer service is equally as shit.

To fix the loud hammering noise on my taco slimsport rack, I added neoprene washers between the wind fairing and the rack mounting points. 5 washer total for each of the 5 mounting points. Figured this out myself because frontrunner customer service was absolutely no help.

Those washers eliminated all noise and rack is quiet now at all speeds. Maybe my experience can help you out.

 

Ive heard you have to use weatherstripping that not just limits the gap but meets the cab. Something with an extra layer like this...