Sounds very much like a bad ball joint. That which you describe is the classic symptom. Even though you recently had them changed, it sounds like the right one has gone bad.
I have seen it before. A new ball joint goes bad in a very short time. Most generally happens with aftermarket ball joints.
Take it back to your shop and have them check it out. Tell them you want the ball joint checked. And make sure they do it. Instead of just throwing other new parts at it first.
'12 F350 SB, CC, SRW, 6.7 PSD, 3.55 RAR, 6 spd auto
2015 DRV 38RSS 'Traditions'
Pullrite Super Glide 18K
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