2003 GMC sierra 1500 4wd front end shimmy

I have a 2003 GMC sierra 1500 4wd 5.3. I have replaced rotors,

pads, lubed front end.With 90,000 mi. the front end has started to

shimmy with and without 7 1/2’ Fisher snow plow. Would upper

ball joints firm up ride? How about an after-market “steering

stabilizer”(basically a horizontal shock absorber)?

Upper ball joints will only improve things if the current ones are worn out or otherwise defective. Have they been checked? If not get them, and the rest of the front suspension. Do so a.s.a.p. if you haven’t done so.

The blade weight and use is promoting premature wear on the front suspension and will require more frequent inspections and service.

An alignment shop will tell you all that needs to be changed. Lower ball joints take a beating when there is plowing involved and the other things wear out too. There is a steering arm, idler arm, tie rod ends and the center link. Wheel bearings can get worn out and loose.