JKS vs Rock Krawler: 2020-2023 Gladiator Control Arms

Choosing rear control arms for the 2020-2023 Jeep Gladiator JT comes down to one problem the Wrangler never had: a 137.3-inch wheelbase. The Gladiator is roughly 19 inches longer than a four-door Wrangler JLU, and the moment you add a leveling kit or a 2-to-4.5-inch lift for 35-inch winter tires, the solid rear axle rotates and slides forward in the wheel wells. Adjustable rear control arms let you re-center that axle and reset pinion angle so the driveshaft stops vibrating. In this comparison we put three in-stock options head to head: the JKS Manufacturing J-Link arms, the Rock Krawler Johnny-Joint arms, and the Fabtech 5-ton link set.

Why does a lifted Gladiator JT need adjustable rear control arms?

A lifted Gladiator JT needs adjustable rear control arms because lifting the body moves the fixed-length factory arms out of their designed geometry, pulling the rear axle forward and rotating the pinion downward. On the JT's long 137.3-inch wheelbase, even a 2.5-inch lift shifts the axle enough to cause tire-to-fender contact and a 3-to-5-degree pinion change — which shows up as a highway vibration and premature U-joint wear. Adjustable arms thread longer or shorter so you can push the axle back to center and rotate the pinion back up toward the transfer-case output.

There are two jobs, and they are handled by two different arms. The rear lower arms set wheelbase and axle fore/aft position — lengthen them to re-center the axle in the wheel well. The rear upper arms set pinion angle — the rotation of the differential that aims the driveshaft. A mild 2-inch leveling setup often only needs adjustable lowers; a 3.5-inch-and-up build on 37s usually wants both uppers and lowers so you can dial the driveline back into spec. Because the Gladiator carries bed weight and tows more than a Wrangler, its arms also see higher loads, which is why DOM steel tube, forged joints and rebuildable ends matter here more than on a short-wheelbase Jeep.

JKS vs Rock Krawler vs Fabtech: rear control arm comparison

Here is how the three in-stock rear control-arm options for the 2020-2023 Jeep Gladiator JT stack up. All are fully adjustable solid-axle arms built to re-center the rear axle and correct pinion angle after a lift. The JKS kits are sold per axle (a pair), the Rock Krawler arms are a rebuildable-joint upgrade, and the Fabtech set covers front and rear lowers in one box.

JKS J-Link rear lower arms: the best value for most builds

The JKS Manufacturing J-Link rear lower control arms are our top pick for the 2020-2023 Gladiator JT because they fix the axle-centering problem for the lowest price of any purpose-built option here. The pair is made from 2-inch outer-diameter, 0.250-inch-wall DOM tubing — thicker and stronger than the factory stamped arms — with a forged flex joint on one end for articulation and a poly bushing on the other for quiet on-road manners. They adjust across roughly a 0-to-4.5-inch lift range using 1-1/4"-12 threads with jam nuts, and they bolt in with no drilling or cutting.

What about rear pinion angle? Add the JKS upper arms

If your Gladiator JT has a highway vibration after a 3-inch-or-taller lift, the fix is the rear upper arms, not the lowers. The JKS J-Link rear upper control arm kit (JKS1637, $359.95 a pair) uses the same 2-inch DOM construction and forged flex joint as the lowers, but it rotates the differential to aim the pinion back at the transfer case. JKS rates the uppers for roughly 0 to 4.5 inches of lift. Running the matched JKS uppers and lowers together — about $720 for all four arms — lets you independently set wheelbase and pinion, which is the correct way to kill driveline vibration on a long-wheelbase truck.

Rock Krawler rear lowers: the trail-abuse pick

The Rock Krawler 2019-and-up Gladiator JT rear lower control arms ($433.06 a pair) are the choice when your Jeep spends real time crawling rock and running big articulation. Their signature is the rebuildable Johnny Joint on the adjustable end: a greaseable, serviceable flex joint that you can tear down and re-ball rather than replace, which matters when grit and water work their way in over years of winter trail runs. Rock Krawler builds the arms with right-and-left-hand threaded ends so you can set length on the vehicle, and they are reusable if you change lift height later. You pay about $73 more than the JKS lowers for that rebuildable joint and heavier trail focus.

Fabtech 5-ton link set: the premium front-and-rear option

The Fabtech Gladiator JT front and rear lower link set ($911.14) is the premium, one-box answer for owners building around a matched Fabtech lift system. Instead of a single axle's worth of arms, this kit covers both front and rear lower links, and it uses Fabtech's 5-ton uniball joints for maximum load capacity and articulation on taller lifts. It is the most expensive option here by a wide margin, but it is also the only one that addresses the front lower links at the same time — so if you are doing a comprehensive long-arm-style refresh rather than a targeted rear fix, it consolidates parts. For most JT owners adding winter tires on a bolt-on lift, it is more arm than the build needs; for a dedicated Fabtech-equipped rig, it is the integrated choice.

Which rear control arms should you run on your Gladiator JT?

Match the arm to your lift height and how hard you wheel. For a 2-to-2.5-inch leveling or lift on 33s or 35s — the most common winter-tire setup — start with the JKS rear lowers at $359.95 to re-center the axle; that alone cures most rubbing. For a 3-to-4.5-inch lift or any build that throws a highway vibration, add the JKS rear uppers so you can also correct pinion angle, for roughly $720 in all four arms. Choose the Rock Krawler lowers if your Gladiator is a dedicated trail rig that will see repeated deep articulation and you want a rebuildable joint. Step up to the Fabtech 5-ton set only if you are running a matched Fabtech system and want front and rear lowers handled together.

A quick install note from our Tampa, FL shop: swap one arm at a time so the axle cannot shift while everything is loose, set each new arm to the factory length first, then lengthen to re-center and re-measure pinion with an angle gauge before final torque. Pair any of these arms with quality shocks and a matched lift kit so the geometry you just corrected stays put under load. You can see the full range in our Jeep suspension collection.