Duramax Front-End Rebuild: Upgrading to Kryptonite Ball Joints and UCAs

If you’ve owned a Duramax for more than ten minutes, you already know the front end is a wear item. Between big tires, heavy loads, and a lifetime of rough roads, ball joints take an absolute beating. And if you’re anything like the rest of us, you’ve probably tried every flavor on the shelf from OEM, Moog, Mevotech, and even that one “lifetime” set that lasted about a year. Eventually, you realize the problem isn’t just finding ball joints that fit; it’s finding ball joints that last.

That’s where Kryptonite Suspension steps in. Its parts have built a reputation for being as tough as they sound, and when it came time to refresh the front end of our LBZ, we decided to go all-in with Kryptonite upper and lower ball joints paired with Kryptonite upper control arms.

The beauty of using the Kryptonite UCAs is that installation of the uppers is almost too easy. Unlike factory-style press-ins, the bolt-in Kryptonite uppers use a clamping-style mount that drops right into place—no presses, no profanity, and no need for a torch. Pop the old ones out, clean the bores, and bolt the new ones in. It’s the kind of straightforward engineering that makes you wonder why GM didn’t design them this way in the first place.

The lowers take a little more patience, as expected. Pressing the factory joints out of the knuckle still takes some persuasion, especially if they’ve been in there since the Bush administration, like ours were. A sturdy ball joint press, a LOT of heat via a MAPP gas torch, and a few creative words go a long way. Once the old joints are out, the Kryptonite lowers slide in cleanly. We always recommend checking alignment tolerances before torquing everything down to make sure everything is kosher. Nobody likes chasing down random IFS gremlins down the road.

But the real story here isn’t just ease of installation; it’s the design itself. Kryptonite’s latest generation of ball joints has seen some serious upgrades—even over its own previous generation of ball joints. Either way, they definitely are a big improvement over stock components. Those upgrades include:

• Powdered metal internal races for unmatched durability
• A chromoly stud that’s practically allergic to bending
• Metal-on-metal internals with a coil spring compression system that maintains consistent tension under load
• A gold zinc cap that looks great and fights corrosion
• Optimized forging clearance for maximum articulation without binding

That last point is worth talking about. The extra articulation is a big deal, especially for lifted trucks or those that see rough terrain. Too little clearance, and you’ll bind the joint under droop. Too much, and you lose rigidity. Kryptonite seems to have hit the sweet spot. Steering feel tightened up instantly after installation, and the front end tracks like it’s brand new.

Now, let’s talk maintenance, because this is where most people get it wrong. These ball joints are not maintenance-free, and that’s not a flaw—it’s the point. Kryptonite built them with metal-on-metal internals for maximum strength and longevity, but that design only works if you feed it grease. They even put it in the literature: grease them with every oil change. Think of grease like blood in your body—without it, nothing survives. Hit the ball joints with a quality chassis grease every 5,000-10,000 miles, and they’ll outlive most of the other components on your front end. Ignore that, and they’ll remind you why maintenance matters.

After installation, we torqued everything to spec, hit it with grease, and sent the truck out for a proper alignment. Even during the first test drive, the difference was noticeable.

There’s something satisfying about doing this kind of upgrade yourself. It’s one of those jobs that reminds you why you like turning wrenches in the first place. There’s no coding, no computer tricks, and no hidden sensors waiting to throw a CEL—just old-fashioned mechanical work. Pull it apart, press it in, torque it down, and take pride in the fact that you did it right.

At the end of the day, the Kryptonite setup isn’t cheap, but neither is doing this job twice. Between the beefed-up design, the precise fitment with the UCAs, and the attention to detail on things like corrosion resistance and articulation, these ball joints are exactly what most Duramax owners have been asking for: durability with real-world serviceability.

So if your front end is starting to clunk, wander, or generally feel like it’s been through one too many potholes, consider this your sign. Grab a press, crack a beer, and give your truck the upgrade it deserves. Just don’t forget the grease gun when you’re done.