recently a friend of mine bought a light bar (40") to top his yota. install was a breeze, and everything went just fine. the first time he hit 35 miles per hour, he wanted to rip the thing off because of the horrible whistling sound it makes. has anyone else had this problem? how'd you deal with it?

 

My 44" whistles around 40'ish. Quits around 55..

 

common issue with light bars and roof racks since you've now changed the air flow across top of windshield/roof. deflector and/or relocation are the only real fixes.

 

With the right tuning you can get them to sound real good and have the pitch change for different speeds .

If your real good you can play music .

One has to look for the good .

 

what kind of light bar is it?

if it is the Rigid style or one of the imitation models, with the cooling fins on the back, you can take the magnesium/aluminum end caps off (seen here, held on by the 4 small hex head screws: http://www.sxsperformance.com/Media/...XA-MODLED1.jpg) and put a piece of rubber or metal underneath it to fill the hole.

Did this on a friend's jeep light bar that was whistling. I used an old sheet of rubber and just cut it out to the shape of the end cap, and sandwiched it underneath the end cap. No more whistling.

This made me think that the whistling came more from air rushing through that hole and through the cooling fins than from the wind flowing between the bar and windshield/roof.

Worth a shot, at least. It's an easy repair.

 

Any idea if the whistling prevents rogue deer assaults on back roads??

 

On my 20" Rigid it whistled a bit when i installed it, so we just stuck a piece of electrical tape on the back - 1 piece right down the middle- took care if it.
When I replaced it with a 40" Rigid, it came with 3 rubber pieces that stick in between the ribs.

 

Found this old topic but I decided to post because there is a good solution to reduce the sound of the lightbars.

So there is company Z-roadz, and they make noise canceling deflectors for their long lightbars. They are bigger than rubber strips and attach with screws, so they will not come off on the freeway.

Zroadz® Z330050S - Noise Cancelling Wind Diffuser for 50" LED Light Bar

They are confirmed to fit on the Zroadz lightbars, but we can't guarantee a proper fitment with the lightbars made by other brands, as we haven't tested them yet.

If this particular item doesn't work for your Toyota, you can DIY something similar