Highway Vibration Troubleshooting

[DelcoGary]

I've got a 2016 XLT 2.3L 4wd with 47k on it. Recently I've noticed some vibration at highway speeds. It starts around 45 mph and continues on as fast as I have cared to go... I feel the vibes more from the back end than in the steering wheel. I'm kind of curious where to start on this as I saw the posts on the failed transmissions and it seems like this is a symptom. It seems to shift "OK" or as well as the 6 speed generally does. I checked for pending codes and all is clear.

Before the most recent "find" the Ex sat for about 2 weeks. I've also had the tires (new Continental TerrainContact) road force balanced about 3-4 months ago. The initial balance was off so the tires have been balanced 2x since I got them about 6 months ago from TireRack. The mobile installer didn't do such a great job initially.

I cleaned the inside of the wheels in case there was any gunk stuck that might throw off the balance and I'll give that a try. Next step is rotating the tires to see if that makes a difference. Any other simple checks that I should start with before assuming the worst?

I wouldn't think that sitting for two weeks would flat spot the tires or that they are defective/out of round but I supposed that could be a possibility. At this point I'm looking for suggestions on simple troubleshooting before a dealer visit.

 

[peterk9]

If you have the 20" tires, it doesn't take long to flat-spot them if the vehicle sits any length of time. It is worse in cold weather but I still notice it occasionally now. When was the alignment checked last? Misalignment can cause vibration usually in the 50-70 mph range. BTW, my first thought was wheel balance issue.

Peter

 

[DelcoGary]

If you have the 20" tires, it doesn't take long to flat-spot them if the vehicle sits any length of time. It is worse in cold weather but I still notice it occasionally now. When was the alignment checked last? Misalignment can cause vibration usually in the 50-70 mph range. BTW, my first thought was wheel balance issue.

Peter

Thanks for the input Peter. I've felt that in my SHO with the Pirelli tires (it has 20s), but the Ex has the 18s and it's been pretty warm, especially since the trip was from PA to VA. When I notice that in the SHO, it usually goes away after a bit of driving. This did not which lead me to think of a tire defect, out of balance issue, or transmission issue.