First and foremost, knurled ball joints are a last resort not a first or better option. They are only to be used on suspensions that have knuckle bores and/or housing end forgings that are so worn they can no longer properly accept a smooth-body ball joint.
A knurled ball joint has grooves machined into its body that serve to fatten the body, allowing the unit to press into an enlarged mounting space tightly. Bore wear can be trail abuse but usually means you have changed ball joints a number of times and the bore has succumbed to the pressure of being pressed in place. The result is those knuckle bores or end forgings have become enlarged or out of round such that a ball joint body which is the correct diameter may not fit.
If you don't need the extra tightness we strongly recommend you don't use a knurled ball joint. Beware. We know that a lot of our competitors and many aftermarket service parts out there automatically come with knurled bodies. The problem is once you install a knurled ball joint you have no where to go when the knuckle bores or end forgings wear. If a knurled joint is your first service part you have sacrificed the future because you have willingly enlarged the bores and down the road you'll eventually get to a point where nothing fits.
So only install a knurled ball joint because a normal smooth body unit will not press in tight enough.
RANDYS offers ball joints from Yukon, Dynatrac, and ICON Vehicle Dynamics, and some applications feature both smooth and knurled body designs.
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