Front Dana 44 swap for 35"+ tires. JK Rubicon front, WJ HD, or aftermarket crate axles. More complex than rear; steering and bracketry change too.
The XJ front Dana 30 runs out at 33-34" tires with chromoly shafts. For 35s+, the next step is a Dana 44 front. Options:
JK Rubicon Dana 44 front (2007-2018): 30-spline (or 32-spline rear Rubicon outers can be swapped), factory e-locker, disc brakes. ~$1500-2500 from salvage. Wider than XJ stock.
WJ HD Dana 44 (some 5.9 Grand Cherokees): rare but bolt-up similar to ZJ. ~$1200.
Ten Factory crate D44 front: 30-spline, ready-to-bolt-up to XJ coil/control arm/track bar mounts. $3500-5000.
Currie Rock Jock 44: built-to-order, with chromoly shafts, hydraulic ram support, 1-ton bearings. $4500-7000.
Swap requirements:
Coil and control arm mounts: must match XJ geometry. JK D44 has different mounts; aftermarket housings have XJ-spec mounts.
Steering arms: XJ uses Y-link steering with specific knuckle mounts. Some D44 housings work with stock XJ pitman; others require crossover steering.
Track bar mount: must position correctly relative to XJ frame.
Brake lines: hose lengths and adapters needed.
Hub bearings vs unit bearings: JK Rubicon uses unit bearings (cheaper to replace); some aftermarket use spindle/manual hubs.
Width: JK D44 is ~3" wider than XJ stock — need flatter fenders, less backspace wheels, and steering compatibility.
Cost: $1500-3000 for salvage-based swap; $5000-8000 for crate axles. This is a major build expense.
For builds going to 35"+ tires, the front D44 swap is the right answer. For 33"-34" builds, a built D30 with chromoly shafts is usually enough.
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.