3 Methods to Rebuild or Repair Your Johnny Joints and Bushings

Johnny Joints are the backbone of every adjustable control arm in the Core 4x4 lineup. They’re tough, rebuildable, and designed for years of trail abuse—but they don’t last forever. When it’s time to rebuild, you have options. In this guide we’ll walk through three different methods to rebuild your Johnny Joints at home, plus how to replace control arm bushings, when to know it’s time, and which grease to use. Whether you’re on a tight budget or want shop-level speed in your garage, one of these methods will work for you.

When to Rebuild Your Control Arms

Before you pull any wrenches, it helps to understand what you’re actually diagnosing. Not every noise or symptom means your joints are blown. Here’s what to look for:

• Lateral play in the joint – This is the real indicator. Grab the control arm near the Johnny Joint end and pry against it with a bar. If you see the joint moving side to side, it’s time to rebuild. A joint that rotates freely by hand is normal—lateral slop is not.
• Clanking or metal-on-metal sounds – This is one of the most common questions Core 4x4 gets. A metallic clank usually means something is loose, not worn. Check your jam nuts, mounting bolts, and any hardware first. Torque everything down before assuming the joint needs replacement.
• Grease leaking around the joint – Some seepage is normal over time, especially on arms that have been in service for years. The JK in this video had arms running for almost five years with grease visible around both the joint and bushing—and the joints were still tight.

Pro tip: Remove and rebuild your control arms with the Jeep on the ground, not in the air. With the vehicle lifted, the axle hangs on the suspension and everything shifts as you pull parts off. On the ground, the brackets stay aligned, and the rebuilt arm bolts right back in without fighting anything.

Greasing Your Control Arms: What, When, and How Often

Proper greasing is the single best thing you can do to extend the life of your Johnny Joints and bushings. Here’s what you need to know:

• Grease type: Use a moly-based grease. Avoid fully synthetic lithium greases. The RockJock Johnny Joint grease works on both the Johnny Joint and bushing sides of the control arm.
• When to grease: Camp and Crawl Series arms ship with the Johnny Joints pre-greased with moly grease, so those don’t need attention right away. However, any bushing end (Camp Series with one bushing, or Cruise Series with bushings at both ends) should be greased at install.
• How often: Re-grease every 10,000–15,000 miles, or roughly every other oil change.

How to Replace Control Arm Bushings

The bushing side of your control arm is the easiest to rebuild. The bushing is a two-piece design that presses into the tube, and all you need is a hammer, a vise, and a flathead screwdriver.

1. Remove the crush sleeve: Place the arm in a vise and tap or press the center crush sleeve out through the tube. Once the sleeve is out, you can access both bushing halves.
2. Pry out the old bushings: Hold the arm lengthwise on your workbench. Use one hand to press the arm down against the table, and with the other hand, get a flathead screwdriver under the lip of the bushing. Pry it away from the tube wall until it pops out. Flip the arm and repeat for the other half.
3. Clean the bore: Before installing new bushings, clean all the old grease and grit out of the sleeve and tube interior.
4. Install new bushings: Apply grease to the new bushings and press them into the tube. They should go in with hand pressure, but a tap from a hammer can seat them fully. Reinstall the crush sleeve.

That’s it for the easy side. Now for the Johnny Joints.

Johnny Joint Rebuild: 3 Methods Compared

Rebuilding a Johnny Joint requires enough pressure to collapse the joint off the internal snap ring. Once that snap ring is out, the rest is disassembly and reassembly. The difference between the three methods below is how you generate that pressure—and how much time and effort each one takes.

Method 1: Bolt and Socket (Budget Method)

This is the cheapest way to rebuild a Johnny Joint. All you need is a long bolt, a nut, and two sockets. It works, but it takes patience.

Tools needed:

• 1-3/16” socket and 1-1/4” socket (sizes may vary—see note below)
• A long bolt and nut that fits through the joint
• Snap ring pliers
• Vise
• Hammer

Socket sizing tip: Make sure your sockets contact only the washer, not the ball center itself. You need enough clearance to access the snap ring groove once the joint is compressed.

Disassembly:

1. Secure the arm in a vise. Place one socket on each side of the joint with the bolt running through both.
2. Tighten the nut to compress the joint. It only takes a few turns until the snap ring groove is exposed.
3. Remove the snap ring with snap ring pliers.
4. Loosen the bolt setup and remove the sockets.
5. Tap out the internals (washers, bushings, ball center) with a hammer. Use a piece of scrap metal on top to avoid damaging your socket.

Assembly:

1. Clean the bore and inspect the ball center. The ball center is reused—clean off any rust or grime.
2. Note the orientation: one of the bushing flanges has a small groove. That groove faces up to account for a slight offset in the ball center.
3. Grease everything. The most important surface is around the ball center where all the articulation happens.
4. Stack the components: washer, bushing, ball center, bushing, washer. Assemble the bushings together first—they interlock to create grease channels. Trying to insert them one at a time usually means starting over.
5. Use the bolt-and-socket setup in reverse to press the assembly back together. Compress until you can reinstall the snap ring.

The downside: Keeping even pressure with this setup is difficult. The sockets tend to shift, and getting the snap ring back in can be frustrating. If you’re only doing one or two joints, it gets the job done. For anything more, consider the next two methods.

Method 2: RockJock Clamp Tool

The RockJock clamp tool (available in 2-inch and 2-1/2-inch sizes) is purpose-built for Johnny Joint rebuilds. At around $120 each, it’s not cheap—but if you rebuild joints regularly, it pays for itself quickly.

What makes it better: The clamp has a long threaded section that lets you apply slow, even, straight-line pressure. This is the biggest advantage over the bolt-and-socket method, where the sockets can tilt and shift. The clamp keeps everything aligned.

Disassembly:

1. Place the clamp around the joint (you don’t use the press portion for disassembly—just the clamping section).
2. Tighten the 22mm nut to compress the joint until the snap ring is exposed.
3. Remove the snap ring and disassemble the internals.

Assembly:

1. Stack and grease the components the same way as described above (washer, interlocked bushings with ball center, washer).
2. Use the clamp’s threaded section to slowly press everything back together.
3. Compress just far enough to reinstall the snap ring. Don’t over-compress—you can bend the washers, especially with the press or clamp tool.

This is the sweet spot for most home mechanics: faster and more controlled than the bolt-and-socket method, and no press required.

Method 3: Hydraulic Press with Press Tool

If you have access to a hydraulic press (even a Harbor Freight unit), this is the fastest method by far. Core 4x4 sells press tool kits in 2-inch, 2-1/2-inch, and bundle options that fit over the joint and provide a backing ring to clear the ball center.

How it works:

1. Set the press tool over the Johnny Joint and place the backing ring underneath to provide clearance.
2. Apply pressure with the press. The snap ring groove is exposed in seconds.
3. Remove the snap ring, release pressure, and disassemble.
4. Reassembly is the reverse—stack, grease, and press back together.

This is how the Core 4x4 shop rebuilds joints daily. A single joint takes just a few minutes from start to finish.

Reassembly and Final Tips

Once both sides of your control arm are rebuilt, apply a thin layer of grease to the bushing wear surface before reinstalling. This makes it easier to slide into the bracket and means you won’t need to grease right away after install.

If you lowered the Jeep to the ground before removal (as recommended), the brackets should still be aligned. The rebuilt arm should bolt right back in without any prying or fighting.

A few final reminders:

• Torque all hardware to spec and re-check after 200–300 miles.
• Re-grease every 10,000–15,000 miles or after any water crossings or heavy mud.
• Metal-on-metal sounds after a rebuild usually mean a loose bolt or jam nut, not a bad joint.
• Ball centers are reusable—just clean them up. Order a rebuild kit for the bushings, washers, and snap ring.

Johnny Joint Rebuild Kits and Tools

Frequently Asked Questions

Related Content

• 2” Johnny Joint Rebuild Kit – Product Page
• 2-1/2” Johnny Joint Rebuild Kit – Product Page
• RockJock Johnny Joint Grease
• Watch the Full Rebuild Video on YouTube