I now have a vibration in the front end at low speeds and higher speeds. Are you familiar with this? I'm afraid to drive it. This truck has been a pain in my arse.

3500 SRW right? Did it start all of a sudden? Driven in the mud before this started? Try rotating tires and see if the shaking moves. Could have slung a wheel weight off. Ball joint, tie rod end may be worn? These trucks also have sealed front wheel bearings. I've heard folks say they've had trouble with them. Starts to vibrate then it begins to get noisy, whines, squeals, roars, etc.. There's no real fix other than replacing the bearings. I got about 90000 on mine and have never had any trouble. It's hard to say what may be wrong without driving it and looking at it on a rack. Take it to a reliable front end shop.... One that likes to work on GM front ends.

I'm not retento, but I am going to add something else to check as well.  Just happened to a 2001 3/4 ton 4x4 I bought.  Truck run and drove prefect then on the way back to work I got a bad shake at low and high speeds, around 40 or so it would smooth out.

Belt seperated in the tire.  When I looked at the tread there was a high spot going the same direction as the tread about a foot long.

Not meaning to high jack, just another thought.

HTB

Good point on the possibility of a "square" tire... Didn't mention them, figured they had already checked the tires...