I believe its quite a bit of work.
Mine makes the thunk when its really cold- and when turning the wheel fast.
(actually quieted down a bit, after I did my preventative maintenance on a bunch of the front suspension around 145,000).
But- as stated by a GM tech on here--- the thunk sound- is not detrimental to driving.
But if it annoys you... get it repaired.
I will simply wait until the Rack and pinion goes out. I can live with the occasional thunk.
2010 FWD LT1-Gold Mist Metallic- seats 8.
Build Date- July 31, 2009-2nd day of Spring Hill 2010 production.
2013 Equinox 3.6L - 88,000
2010 Traverse 3.6L- 153,000
2003 Trailblazer 4.2L- 181,500