2003-2013 Cummins Adjustable Ball Joint Kit (4123KN)

Fits:

Tighten up your steering for good with this patent-pending design by Synergy; which is fully adjustable, serviceable, and rebuildable without having to press the ball joints back out of the axle end forging yokes. 

CNC machined from 4140 steel, heat treated, induction hardened, & ferritic nitrocarburized to make these the longest lasting, longest wearing ball joints on the market; let this be the last set of ball joint you ever have to buy.

Part Number: 4123KN

• Lower ball joints are adjustable to ensure correct amount of preload
• Knurled and non-knurled ball joint housing options to fit any vehicle
• Lower ball joints are rebuildable on the vehicle without removal
• Lower Ball Joint bearing surfaces are CNC machined from 4140 steel, heat treated, induction hardened, and ferritic nitrocarburized for extreme wear resistance
• Low profile dust boots are made from thick nitrobutile rubber (NBR) to protect the joint from contaminants and eliminate any chance of tearing
• Zerk fittings included for trouble-free maintenance

• Tightens sloppy steering
• Designed to last the life of the vehicle
• Never need to replace ball joints again
• Best in class price/performance ratio
• Limited Lifetime Warranty

• Synergy 4119 High Performance Grease recommended
• Knurled ball joints required when replacing knurled ball joints that have enlarged the axle end forging bores
• Non-Knurled ball joints recommended for replacing non-knurled ball joints
• Due to these ball joints being tight tolerance, metal on metal ball joints, proper fitment is critical. Using the wrong style of ball joints can cause significant steering issues. We always recommend installing non-knurled ball joints until non-knurled ball joints are no longer a press fit into the axle end forging bores. If your axle end forging bores have been enlarged to the point that non-knurled ball joints are no longer a press fit, knurled ball joints are required.
• Use of the improper ball joint style for the axle housing voids the lifetime warranty. It is up to the installer to verify the proper ball joint style is being used.
• Compatible with RCV axle shafts