CO_Fletch
Member
Thought I would post this in case anyone else has this issue as it took me a while to troubleshoot.
The symptom was an odd vibration sound, almost like a fluttering that would change with speed. It would start off barely noticeable at about 30mph and get more noticeable as speed increased.
I tried shifting into neutral at the higher speed to determine if it was something engine or transmission related - no change in noise by going to neutral so probably not trans or engine related. I then tested each front wheel bearing - jacking up, grabbing wheel at 12 and 6 oclock and trying to wiggle wheel. Both front wheels were tight. I tested that transfer case was operating in 4H and 4L both center locked and not, no apparent issues. I jacked up front of car and put into neutral to hand rotate front wheels to see if anything appeared, nothing. Did same with rear wheels, nothing.
Double checked all skid plates and looked for anything lose around the lower front area, nothing.
Then I found it - the front driver wheel well flap, the rubber piece that covers the gap between frame and body was only attached by the rear clips. While car was stationary, it was not noticeable because it laid in place as normal. Apparently as speed increased, it would flap around and cause the noise and vibration. This was actually on our GX470 but the same thing could happen on the 4th Gen as the setup is exactly the same.
Best thing was the fix was cheap even though it took a while to troubleshoot
The symptom was an odd vibration sound, almost like a fluttering that would change with speed. It would start off barely noticeable at about 30mph and get more noticeable as speed increased.
I tried shifting into neutral at the higher speed to determine if it was something engine or transmission related - no change in noise by going to neutral so probably not trans or engine related. I then tested each front wheel bearing - jacking up, grabbing wheel at 12 and 6 oclock and trying to wiggle wheel. Both front wheels were tight. I tested that transfer case was operating in 4H and 4L both center locked and not, no apparent issues. I jacked up front of car and put into neutral to hand rotate front wheels to see if anything appeared, nothing. Did same with rear wheels, nothing.
Double checked all skid plates and looked for anything lose around the lower front area, nothing.
Then I found it - the front driver wheel well flap, the rubber piece that covers the gap between frame and body was only attached by the rear clips. While car was stationary, it was not noticeable because it laid in place as normal. Apparently as speed increased, it would flap around and cause the noise and vibration. This was actually on our GX470 but the same thing could happen on the 4th Gen as the setup is exactly the same.
Best thing was the fix was cheap even though it took a while to troubleshoot
