4x4 very shaky

[Cjhstang]

when i engage the 4x4 the steering becomes very difficult. it feels like it pulls the wheel left and right with some vibration. once i'm moving over 35mph the vibration and steering issue is gone. I did however notice that these issues continued even once the 4x4 shifter was disengaged BUT the hubs were still locked.

u-joints?

[hunterb2]

You alomost certainly need new u-joints on the front axles. It sounds like one of them, at least, (there are 3) is siezed. It's a bit of a job to change them. If you're driving a F-250 then the passenger side has two u-joints and the inner one is a MAJOR pain to change. It's usually OK though, it's most likely the outer ones. I would look there first judging by your symptoms.

Bruce

[cdnsarguy]

Once the hubs are locked the complete 4X4 drive system is moving only the transfer case is not locked in.