Vibration at High Speeds

Maintenance/Repairs
1

I have a 2008 Chevrolet Trailblazer. I have had 4 of these vehicles and have been very pleased. This latest one has 61000 miles and occasionally has a very strange vibration at speeds above 60 mph. It only happens occasionally and most often occurs at these higher speeds and worsens with increased speed (of 70-73 mph). The vibration is so alarming, that I will press my brakes to slow down, because it feels like the vehicle is starting to lose control. The problem is that when I press the brakes, the vibration intensifies about 3-4 fold! It feel as if the wheels are going to come off. It’s a very frightening feeling. I have taken it to the shop and no one seems to know what it is. The tires are fine. Brakes are fine. Interestingly enough, if I lower the speed to 50-55 mph, the vibration lessens and eventually completely goes away.

Suggestions? I need to know a) If this can be fixed, what do I do? or b) if it’s a serious problem, should I trade this vehicle off before it becomes a major issue that is irreparable or massively expensive.

2

This problem should not be too difficult for a good mechanic to find. Some things to check would be the usual front end components (tie rod ends, bushings, ball joints, etc), steering stabilizer if so equipped, shock absorbers, wheel bearings for play, CV joints if 4WD, brake rotors for pitting/runout, and rim and tire damage or defects.

This is definitely a problem that needs to be checked out and fixed. The way you describe it sounds like the famous “death wobble” common in Jeeps and 4WD pickups with solid front axles. The difference is that your TrailBlazer does not have a solid front axle or a track bar, which is the part that frequently goes bad on the aforementioned vehicles afflicted with the death wobble. Due to the age and mileage of your TrailBlazer, I’m leaning towards a wheel/tire issue rather than a suspension issue. It would be unusual for such a new vehicle to have the suspension shot at such an early age.