New 4130 Upper control arms
Durable, Smooth, Silent.
Built to solve real problems. No squeaks, no maintenance, no headaches.
Whether you’re daily driving, overlanding, rock crawling, or chasing desert trails, these arms handle it all. 4130 Upper Control Arms are built with Probearing’s Heavy Duty ball joints. These joints aren't OE replacements, they're purpose-built for off-road performance to deliver superior articulation and durability. Alongside these joints, SilentSpin™ bushings eliminate grease and squeaks. That means a quiet ride, zero maintenance, and no grease gun. We proudly preassemble and manufacture them in the USA. These are the last set of UCAs you’ll ever need.
Get yours now
Starting at $899 or $82/mo. with Affirm
More applications dropping this summer and fall. Subscribe to our email list to not miss an update.
Now featured in our
MT TRAIL RUNNER KIT
4.9
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Improved ride, leveled stance, and real off-road performance. All in one ready-to-install package.
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What Makes 4130 Different
4130 Upper Control Arms are built to endure abuse, day after day.
Probearing HD
Ball Joints
Built for off-road performance, 4140 heat-treated, 76° articulation
SilentSpin™ Bushings
Zero grease, zero noise, smooth articulation without the upkeep
4130 Chromoly Strength
Built with 4130 chromoly for maximum strength and reliability under extreme conditions
Geometry Corrected
Keeps alignment dialed with up to 3” of lift
More Down Travel
Gain about 1" over stock making it perfect for aftermarket shocks
Rebuildable
Simple process to replace wearable components
Weather-Protected
Zinc hardware and black powder coat resist rust and wear
All Necessary Hardware
Includes UCA bolts and other essential components
What Makes 4130 Different
Probearing HD Ball Joint
Built for off-road performance, 4140 heat-treated, 76° articulation
SilentSpin™ Bushings
Zero grease, zero noise, smooth articulation without the upkeep
4130 Chromoly Strength
Precision-welded 4130 chromoly tubing with reinforced gussets
Geometry Corrected
Keeps alignment dialed with up to 3” of lift
More Down Travel
Gain about 1" over stock making it perfect for upgraded shocks
Rebuildable
Simple process to replace wearable components
Weather-Protected
Zinc hardware and black powder coat resist rust and wear
All Necessary Hardware
Includes UCA bolts and other essential components
It's not theory. It's proven. Probearing™ Heavy Duty ball joints are tested to 1 million cycles.
It's not theory. It's proven. Probearing™ Heavy Duty ball joints are tested to 1 million cycles.
Probearing Heavy Duty Ball Joints
Heavy-duty chromoly joints deliver high articulation and superior strength, sealed to block out debris.
Probearing SilentSpin™ Bushings
Maintenance-free bushings eliminate grease fittings and unwanted noise, ensuring a quiet and responsive ride.
DESIGNED TO PERFORM AND IMPRESS
Every arm is CAD-designed, CNC-machined, and quality-checked to reflect our commitment to strength, support, and craftsmanship.
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About Us
Dirt King develops advanced suspension systems for most vehicle makes and models. All of our products are held to the highest standards with quality setting us apart from the rest.
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