So, as discussed in a few other threads, I have a horrible vibration in the truck at 40mph+. It feels like a front end vibration, as it comes through the steering wheel quite badly. The vibration period is sinusoidal; about 40 seconds of vibration, increasing to a max then decreasing to 20 seconds of no vibration.

Here is where I am at as of now:

It doesn't feel like an out of balance tire: I did the airsoft mod, and can feel when they are not working, feels like an egg for a tire, this is not the same vibration I'm complaining about.

Welded the steering column, and it solved most of the clunking in the column. Still need to shim the ball, but it is not bad except for when the vibration happens

Bushings (control arms and steering rack), ball joints were replaced in 08? They feel good, but will recheck soon.

Wheel bearings replaced in 09 or 10

No front sway bar

Inner and outer tie rod ends replaced ~1 year ago and did not help.

Alignment is incorrect on left side. Will correct next week.

Nothing appears to be bent, cracked, loose, etc. It will get a complete check soon.



Here is my short list of what I think it might be:
Bad tire/wheel
The aforementioned bad alignment
Steering rack bushings
Steering rack
Worn out control arm bushing or balljoint
Cracked frame
Out of balance half shaft

Plans:
Fix bad alignment
Rotate front tires to rear
check everything else for play, wear, etc.


Tires were replaced 2 years ago. I have had this vibration longer than the tires. In fact, I can't remember a time when I didn't have it, but I know it wasn't always there.

I'll try to get some video of the vibration too.