Very specific hum/howl between 69-74 mph

[TRX801]

Hello, I just bought my TRX last week. 2022 with 19k miles. On my drive home I noticed a front end hum noise that I could also feel on the floor board right as I got closer to 69 mph up until around 75 mph. Most noticeable is between 70-72 mph as it is constant. Very acoustic. Wife says she can feel it on the passenger side floor board as well. As soon as you slow down below 68 it goes away but if I get it back up to around 69 it comes right back. Very easy to replicate. Truck does have a ram bar with off road lights. No bed cover. Road surface does not matter.

I had a brand new set of factory takeoffs from a previous TRX I owned laying around hoping it would fix the problem. I through them on but the noise/floor board vibration is still present at exact speeds. Has anyone else had this problem or have any ideas what I could check before taking it to the shop? I tried searching but results were very minimal. Also, this is my fourth TRX in the span of 6 years so I’m fairly familiar with the driveability of the these trucks, which nosies are normal and which are not. Thanks.

 

[Louk]

Something loose or out of place comes to mind. Aftermarket exhaust? Something loose with that or significant drone from it?

Skid plate/something aftermarket underneath?

I would start poking around and start tapping on things to see if something vibrates.

 

[RAMTRX22]

What tire pressures are you running? I would guess something simple like one or two of them are not balanced perfectly.
Four trucks in 6 years what's up with that lol jk.

 

[TRX801]

Something loose or out of place comes to mind. Aftermarket exhaust? Something loose with that or significant drone from it?

Skid plate/something aftermarket underneath?

I would start poking around and start tapping on things to see if something vibrates.

Exhaust was stock up until two days ago I had some SLP Loudmouth resonators installed. Nothing changed. Just did my oil change a couple of days ago and removed the skid plate and checked the front wheels for play and nothing there. Everything is solid including cv axles and front drive shaft. Noise still present. I don’t want to throw parts at it but I may start with a wheel hub but I’ll feel like it is too high of speed to be a wheel hub.

 

[TRX801]

What tire pressures are you running? I would guess something simple like one or two of them are not balanced perfectly.
Four trucks in 6 years what's up with that lol jk.

Tire pressures are at 40. The previous set was at about 41 or so. I may take them to get balanced as it is the least expensive route but I just find it odd that it is still going on even with the new set I through on. At the exact same speeds.

Ya I’m crazy lol the first one I bought when they first came out and I feel like I paid too much so I had it for 6 months and got lucky to get my money out of it. Second one I bought about a year later but it was an insurance theft recovered on which I purchased way below market ($35k cheaper than market price, hence no warranty) I had that for one for over two years and sold it as I racked up the miles but by far the best one I owned. Third one was black which I instantly regretted. Kept it for like 5 months. I hated the upkeep with black. Now I’m back to another theft recovered silver one lol

 

[TRXNUT]

Check the manufacturing date on your "new to you" tires. Just because they were "new take offs" doesn't mean that they haven't gone bad. Tires have a shelf life, the rubber compound starts to get hard, they will start to dry crack too. I think tires shelf life are good for 5 years? If those came off a MY21 truck then the tires could be from 2019-2020 to begin with.

 

[Digerati]

4 trxs in 6 years is wild! welcome back man. buying a theft recovery at a massive discount is a really smart move, but they definitely come with some mysteries.

first off, since you threw your spare wheels on and the hum is happening at the exact same speeds, you can completely rule out tire balance. don't waste your money taking them to the tire shop. the odds of two totally different sets of tires having the exact same imbalance harmonic at the exact same mph is basically zero.

for a "very acoustic" hum and floorboard vibration peaking right at 70-72mph, test your ram bar off-road lights first. wind buffeting against those pods at highway speeds creates a crazy low-frequency drone that travels straight down the cab pillars and vibrates the floorpans. wrap the lights tight in some thick towels and painters tape, and go for a quick highway pull. if the noise changes pitch or disappears, you found it.

and yes, just to confirm, the TRX absolutely does have an ANC (active noise cancellation) system. it uses 4 microphones in the headliner to monitor cabin noise. since you just mentioned installing those SLP loudmouth resonators, there is a very high chance the new exhaust frequency is confusing the ANC mics. when that happens, the module pumps a heavy low-frequency bass drone through the cabin speakers to try and "cancel" the noise, which feels exactly like a physical floorboard vibration. the module is located right under the driver's seat. you can just reach under there and unplug the harness to completely rule it out.

if it’s not the lights or the ANC, my money is on the front driveline. since it’s a theft recovery, you have no idea how the tow company dragged it. if they flat-towed it from the rear with the front wheels rolling on the ground, it absolutely cooks the front diff pinion bearing and transfer case since it is full-time 4wd. even if the front driveshaft feels perfectly tight by hand, a wounded pinion bearing will send that exact high-frequency harmonic straight into the passenger floorboard at highway speeds. an easy free test is to just unbolt the front driveshaft, leave it in the garage, and go hit 72mph.

try wrapping the lights and unplugging the ANC first since both are free and take 5 minutes. let us know what you figure out man!

 

[XSTNKT]

Front wheel hub is my guess.

 

[TRX801]

Yes they are stamped 11/21. I just find it odd that the noise is exactly the same, floor board vibration, with the original tires and the “new” set I put on.

4 trxs in 6 years is wild! welcome back man. buying a theft recovery at a massive discount is a really smart move, but they definitely come with some mysteries.

first off, since you threw your spare wheels on and the hum is happening at the exact same speeds, you can completely rule out tire balance. don't waste your money taking them to the tire shop. the odds of two totally different sets of tires having the exact same imbalance harmonic at the exact same mph is basically zero.

for a "very acoustic" hum and floorboard vibration peaking right at 70-72mph, test your ram bar off-road lights first. wind buffeting against those pods at highway speeds creates a crazy low-frequency drone that travels straight down the cab pillars and vibrates the floorpans. wrap the lights tight in some thick towels and painters tape, and go for a quick highway pull. if the noise changes pitch or disappears, you found it.

and yes, just to confirm, the TRX absolutely does have an ANC (active noise cancellation) system. it uses 4 microphones in the headliner to monitor cabin noise. since you just mentioned installing those SLP loudmouth resonators, there is a very high chance the new exhaust frequency is confusing the ANC mics. when that happens, the module pumps a heavy low-frequency bass drone through the cabin speakers to try and "cancel" the noise, which feels exactly like a physical floorboard vibration. the module is located right under the driver's seat. you can just reach under there and unplug the harness to completely rule it out.

if it’s not the lights or the ANC, my money is on the front driveline. since it’s a theft recovery, you have no idea how the tow company dragged it. if they flat-towed it from the rear with the front wheels rolling on the ground, it absolutely cooks the front diff pinion bearing and transfer case since it is full-time 4wd. even if the front driveshaft feels perfectly tight by hand, a wounded pinion bearing will send that exact high-frequency harmonic straight into the passenger floorboard at highway speeds. an easy free test is to just unbolt the front driveshaft, leave it in the garage, and go hit 72mph.

try wrapping the lights and unplugging the ANC first since both are free and take 5 minutes. let us know what you figure out man!

will give these a shot, thanks for the reply as this is very helpful information!

 

[TRXNUT]

Yes they are stamped 11/21. I just find it odd that the noise is exactly the same, floor board vibration, with the original tires and the “new” set I put on.

will give these a shot, thanks for the reply as this is very helpful information!

Oh I didn't catch the part where you said the noise is the same with both sets of tires. That would eliminate the tires then.