So I have a 2001 Suburban 4X4 that has suspension mods and big wheels. Over the past 50K miles the steering wheel has been shaking (progressively worse as the miles racked up). I know the mods are not helping the situation, but it didn't do this for about 20K miles after I modded it.
Recently it got to the point that I figured it's time to fix it. So far I have replaced the tie rod ends, the pitman arm, the steering box, the sway bar end links, and the sway bar bushings, and shocks (all 4). I've had the tires replaced, balanced multiple times, and rotated, all to no avail.
The steering feels a lot tighter, but still shakes bad. Below are two video's. One with the shake and the other without. These videos are taken back to back on the same road with no turning between video's (so tire balance within each other are identical).
I might add that it only shakes between 45-52mph and even then it'll only do it 25-40% of the time.
Also note worthy, my wheels were bought and build for my Suburban from the manufacturer. The offset, lug center, hub centers, and back spacing all match my truck to a tee because I ordered them that way, these are not Craigslist bought wheels.