High Frequency vibration at highway speed (2 Viewers)

[Phat98]

Hi. I get a high frequency vibration at highway speeds. This vibration comes and goes but is becoming more frequent. It generally comes on as I drive or after I turn off my cruise control and the truck seems to tighten up instantly with this vibration.
Truck has 282k miles. All New rotors and brakes up front and in the rear. New bearings in the front, properly torqued. all new shocks. New rear drive shaft. Everything else is good.
Truck is great to drive, beautiful and smooth all the time unless this vibration come on. No obvious signs of issues with tie rods or ball joints.
My only other issues is my brake booster squeals at start up and my transfer case won't shift into low (incredibly stiff). Slight leak from rack too.
Thoughts?

 

[Trunk Monkey]

Tire balancing and alignment would be first places I would go.

 

[rexington14]

+1 on tires.
Get the brake booster checkout out ASAP - squealing / noises are one of the warning signs. It's a safety hazard that can cause complete loss of braking when it does go out

 

[GerLC100]

You could check whether or not all weights are still on the wheels. Sometimes you can see the tape residues and easily see one out x is missing

 

[Phat98]

Could it be in the rear end axle, front drive shaft or maybe an issue inside the transfer case?
I will double check wheel weights. Again there isn't always a vibration at speed. Thx

I've had all the wheels straightened by a professional service and re-powder coated and balanced shortly after purchase. Front end alignment too. The truck sat for about 3 years on a driveway. Tires are in great shape. Stock 275/70/16. Michelin LTX.

 

[leveeguy]

If the tires sat on driveway not moving for three years there’s bound to be a tire related issue.

Other wise Drain and replace gear oil in center rear and front diffs if haven’t recently and grease u joints and drive shafts for good measure