Shake while driving

[Daytripper]

I've been chasing a shake/shimmy in my truck now for 6 months....
New kingpins, new steer, and drive tires. Nee shocks, new u-joints and driveshaft balanced(no carrier brg.) Tightened all u-bolts. Dial indicator shows .060 out of found tire(left front). I feel the shake more in my seat....not in the wheel. Radial wobble is about .006 so that isn't a issue. Internet info I found says .080 is acceptable? Idk?

[Daytripper]

Will be checking the run out on my drives tomorrow(I'm running recaps)...I suspect that one of them may be out of round...but this truck has had this shake for quite a while(long before I bought it)...the mirror supports were literally worn apart from the vibration...

[Magard]

I would start looking at brake drums. Cheap drums aren’t balanced. I always use the lightweight more expensive drums because there balanced.

[Brock]

A friend of mine had a similar issue, had a shop throw all tire/rims on a balancer and they said they were all good but he decided to hold a pencil near one to see and sure as shi#t..... one of his rims was bent! The balancing place missed it but after a new rim he was good to go.

[Creek]

Is it possible the steer rims have been curbed? Doesn't take much at all to get a wobble. Be careful.

[DVT873]

Check your motor mounts, especially the rear and your cab mounts. I am guessing you have an air ride suspension. Find out what your ride height spec is and how it is measured. Check loaded and unloaded. With age some ride height valves lose their ability to respond to load. Height will be in spec without a trailer on. Hook up a trailer and check it again. Out of spec will change the driveline angles and can set up vibrations.....I am aware of 2 smartphone based apps that can be used to find the frequency of the vibrations and the magnitude. I have not yet tried either. VibSensor is free. The other is NVH by vibratesoftware. NVH is $400. I am told that both are accurate. VibSensor is great if you are an engineer and can do your own interpretation of the data. NVH is aimed at auto and MD/HD truck and provides interpretation and help. Frequency varies based on the component. Magnitude point to how far out of balance it is. This information can narrow down the problem area. $400 is a lot but still less than the $5,000 Eaton/Roadranger system. Then there is old school. https://www.youtube.com/watch?v=weDiELpXlpk&t=21s I am told that this device can also be used to find frequency. Anyway look for simple first.