I agree, go with a "wet bolt" (shackle bolts) upgrade kit. The OEM shackle bolts use a thin wall plastic bushing, when that starts to wear then one experiences a metal-to-metal condition...., and the shackles start to deteriorate (bolt clearance hole through the shackle elongates).
A wet bolt upgrade comes with bronze bushings, plus now you can grease them. Also, the kits come with a heavier duty shackle as well.
I installed a wet bolt kit in my TT a number of years ago, no noise and no wear to-date.