This must-have upgrade will put your mind at ease. This kit will fix the design flaw caused by the stock bolts. The problem arises because the holes for the tracks bars (TB) are 9/16” while the factory bolts are 14mm. This creates a small clearance issue. The other issue is the factory bolts are completely threaded to the head. The threads come into contact with the metal sleeve in the bushing. Both of these factors will cause the bushing sleeve to wear down and become loose over a fairly short period of time causing damage and eventually death wobble. Our upgrade kit provides everything you need to replace the bolts for the Front Track Bar, and Rear Track Bar. New bolts will match factory 9/16” holes and new bolts have shoulder to prevent threads from coming into contact with bushing. Kit contains high strength Grade 8 hardware. Includes hardened extra thick washers (2 per bolt) that will not deform like standard washers and hex locking nuts. All hardware is yellow zinc to prevent rust. We also include (1) M14 Bolt for the Front Frame Side Track Bar Bracket for newer 2012+ Jeep JKs JKUs.