Overview
The JK CORE 44 high pinion front axle with a 4.56 ratio and ARB Air Locker, part C4JMFL456AP5, fits 2007–2014 Jeep Wrangler (JK) models in both two-door and four-door bodies. It is built on a high pinion Dana 44 housing with extra caster for lifts of 6 inches and up.
The axle uses a new generation 8.8-inch JK 44 ring and pinion with a larger pinion shaft, 1.5-inch 35-spline Chromalloy shafts and a factory-style flange pinion yoke. The housing is designed for heavier loads than a stock Dana 30 or Rubicon Dana 44 carries.
Key features
- High pinion front layout with additional caster built in for lifts of 6 inches and up
- New generation 8.8-inch JK 44 ring and pinion with a larger pinion shaft
- USA-made 4340 Chromalloy 1.5-inch 35-spline axle shafts
- Heavy-duty Dana Spicer 5-7166X axle u-joints
- Massive forged inner C-ends and integrated skid plates on the lower control arm mounts
- Heavy-duty 1/4-inch laser cut brackets and 3-inch diameter, 5/16-inch DOM tubes
- Heat-treated aluminum differential cover with cooling fins
Setup and break-in for a locker
A high pinion front axle changes the geometry of the drivetrain, so the pinion angle and driveshaft work together. Extra caster built into the housing is meant to keep the pinion angle in a healthy range on a lifted truck, but the lift height still decides how much the angle moves. Measure the pinion angle after installing the axle and again after any lift change.
A 4.56 gear set paired with a locker is a setup that rewards a careful install. Gear mesh and backlash should be checked by a shop with the right tools, and the carrier should be run through a break-in period before heavy off-road use. Use gear oil suited to a locking carrier and a high-pinion housing.
Tire size and gearing affect each other. Larger tires lower the effective gear ratio, so the ratio should be matched to the tire you plan to run. The locker adds grip on loose terrain but also changes how the truck handles on pavement, so practice turning with it engaged before trail use.
Specifications
| Brand | G2 Axle and Gear |
|---|---|
| Part number | C4JMFL456AP5 |
| UPC | 631410120431 |
| Position | Front |
| Housing type | 07-up Jeep JK Dana 44 |
| Gear ratio | 4.56 |
| Traction device | ARB Air Locker |
| Axle spline | 35 splines |
| Axle shafts | USA-made 4340 Chromalloy, 1.5 inch, 35 spline |
| Axle tubes | 3 inch diameter, 5/16 inch DOM |
| Carrier bearings | Metric Rubicon-style |
| U-joints | Dana Spicer 5-7166X |
| Differential cover | Heat-treated aluminum with cooling fins |
| Wheel bolt pattern | Reuse factory ends |
| Brakes | Reuse factory |
| Fitment | Direct fit |
Vehicle fitment
It fits 2007–2014 Jeep Wrangler (JK) models, covering two-door and four-door versions.
For 2015–2018 JK, TJ, LJ, JL or Gladiator models, confirm fit for your year, model and trim before ordering.
Installation notes
This is a complete front axle, and the wheel ends and brakes are reused. A 4.56 gear set with a locker needs professional setup and break-in. Lift heights of 6 inches and up are the case the extra caster is built for, so check your lift height before fitting.
What’s included
The complete high pinion front axle assembly with the ARB Air Locker and 35-spline Chromalloy shafts.
