IRO's bolt-in 3-link long arm conversion is the most popular XJ long arm system. Solves the geometry compromises of 4.5"+ short arm lifts.
The IRO ROCK-LINK long arm system replaces the stock front lower control arms with much longer arms that mount to a new bolt-in crossmember several feet rearward of stock. This dramatically flattens the control arm angle at ride height, which means under articulation the pinion angle barely changes and the rig no longer suffers from "short arm bounce" on washboards. Available as 5.5" and 6.5" full kits, or as a long arm upgrade (LAU) that bolts to an existing IRO short arm kit's coils and rear pack.
The LAU front conversion bolts to the unibody — no welding required on most years (some early XJs have a slightly different crossmember and may need a single weld-on plate). Adapter 14418 is required for 4-cylinder/AX-5 trucks; adapter 13397 for Peugeot transmission trucks; trans mount 2625 for 2000-2001 autos. The kit includes the long lowers, the crossmember, adjustable upper control arms, brake line drops, and HD front track bar. Expect $1500-2000 for the LAU front, $3000-4000 for a complete 5.5" or 6.5" kit.
Rear long arm is typically NOT installed on an XJ because the rear is a leaf-sprung axle (no control arms to lengthen). Some builders convert the rear to a 4-link with coils as part of a full SOA-style rebuild, but the ROCK-LINK is a FRONT long arm conversion.
At 5.5-6.5" of lift you must have SYE/CV, extended brake lines, caster correction (already in the kit via adjustable uppers), and a properly set up rear track bar. The result is a rig that rides like a proper trail truck — far better on highway than a 4.5" short arm and dramatically better on the trail.
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| Part | Vendor | Est. price |
|---|---|---|
| IRO ROCK-LINK Front Long Arm Upgrade | Iron Rock Off Road | ~$1700 |
| IRO XJ 5.5" ROCK-LINK Full Kit | Iron Rock Off Road | ~$3400 |
| IRO XJ 6.5" ROCK-LINK Full Kit | Iron Rock Off Road | ~$3700 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.