Why does my gen 3 feel like crap on highway?

[ChrisCosta416]

Have you checked your wheel bearings? Wheel bearings can cause a loud rumble noise when driving.

My 3rd gen got louder with a lift and more aggressive tire noise. Also note there is almost no sound insulation in the cargo area!

 

[1morebike]

I drove this thing over bridge that was mostly grates and it was damn scary I had a hard time keeping it in my lane. I had my tire place check out the ball joints and ti rod ends a few weeks ago when I got my tires rotated and they said they were fine...they also said my brakes were good and we went on 250 Mile road trip and right before home getting of the highway I hear tink sound and then noise from my right front brake. Turned out to be a caliper bolt feel out...

 

[Skidmarkart]

It's funny, I have been having a similar issue with my Gen 3 as well. Around 50 MPH it has a deep ... I don't know... rumble/vibration of sorts. I am running 100% stock gear, with normal sized tires. It's really hard to put my finger on the issue, and I have had the same tires for 30k miles. It feels like a transmission or drivetrain issue, but I can really put my finger on the source of the sound. Visual inspection reveals nothing, everything looks clean and to be in good shape, shock don't seem to be worn out (though I guess they could be). Anyway, I'll be curiously watching this thread and perhaps contributing (I am getting to the point where I have to take it to a pro). Sniff... and probably drop some $$$ for the repair.

 

[HMSEndeavour]

It's funny, I have been having a similar issue with my Gen 3 as well. Around 50 MPH it has a deep ... I don't know... rumble/vibration of sorts. I am running 100% stock gear, with normal sized tires. It's really hard to put my finger on the issue, and I have had the same tires for 30k miles. It feels like a transmission or drivetrain issue, but I can really put my finger on the source of the sound. Visual inspection reveals nothing, everything looks clean and to be in good shape, shock don't seem to be worn out (though I guess they could be). Anyway, I'll be curiously watching this thread and perhaps contributing (I am getting to the point where I have to take it to a pro). Sniff... and probably drop some $$$ for the repair.

Could be brakes. I had a really bad rumble/vibration at around 70Km/h to 100km/h (probably around 50 mph?). To the point where I had trouble reading my GPS. Turns out I had 1 seized caliper and the parking brake was also partially engaged on one side. I had the garage disconnect the problematic half of my parking brake and the issue went away. While the Montero generally seems to hold up well to rust, it seems the parking brake and the rear door latch are both very susceptible.

I have read elsewhere that the transmission mounts loosen up over time and can cause vibrations as well.

 

[1morebike]

All good things to look into. I'm very suspect of my brakes even though my mechanic did new calipers, rotors, and brake lines. 6 months after the left caliper was seized again. It was replaced under warranty then a caliper bolt fell out getting off the highway .

 

[Skidmarkart]

Hmmmm... I did get new brakes not too long ago myself. Perhaps I will remove the wheels and inspect them against before I take it to the mechanic.

 

[1morebike]

Hmmmm... I did get new brakes not too long ago myself. Perhaps I will remove the wheels and inspect them against before I take it to the mechanic.

I would check them. I'm still not convinced mine are fine I think I'm going to have to get a second opinion my brakes have been a problem since I bought the truck two years ago. That being said I think mine feels like yours I have had my drive line checked twice by my mechanic but I think I'm going to take it to drive train specialist just to make sure. I'll keep this updated as I throw money at and see if I can find a solution.