HELP: Violent steering wheel shake

[JVMet730]

2001 Tahoe
250k miles
New wheels and tires

Like title says I get a violent steering shake. The shake was always there and recently bought new wheels (oem 20s) and new tires, perfect mount and balance and I was certain it wasnt a tire or alignment issue. Well since the swap the shaking is getting worse. It happens at 50-55 MPH and only when the steering is in a straight path and line. If im making and sort of turn it does not do it. Once I get around 60 or so it stops and is fine and same with under 50-60 mph. Any suggestions appreciated it's driving me nuts. It's so bad the whole truck shakes and when I say the steering wheel shakes and jerks around it's pretty extreme where I don't even want to drive it. Thanks in advance.

 

[large]

Check ball joints and wheel bearings first

 

[OR VietVet]

Inspect the entire front suspension and entire steering linkage. Make sure to jack under the lower ball joint as close to d of lower control arm, close to tire, as possible. Get the tire off the ground about 1-2 inches and then use a long pry bar under the tire at 6 o'clock and lift up and release and check for ball joint play, upper and lower. Grab tire at 3-9 o'clock and 12-6 o'clock and check for wheel bearing play. Check looseness a the tie rods and idler/pitman arms. Check steering shaft.

 

[OR VietVet]

Inspect the entire front suspension and entire steering linkage. Make sure to jack under the lower ball joint as close to d of lower control arm, close to tire, as possible. Get the tire off the ground about 1-2 inches and then use a long pry bar under the tire at 6 o'clock and lift up and release and check for ball joint play, upper and lower. Grab tire at 3-9 o'clock and 12-6 o'clock and check for wheel bearing play. Check looseness at the tie rods and idler/pitman arms. Check steering shaft.

 

[SLCHOE]

I agree, shakedown the front end focusing on wheel bearings, tie-rods and ball-joints. If 4WD also look at your front driveline u-joints for play.