Overview
The Rubicon Express RE3780 is a pair of Super-Flex adjustable front upper control arms for Jeep TJ and LJ Wranglers, XJ Cherokees, MJ Comanches and ZJ Grand Cherokees, based on the chassis codes in the product title. Each arm is a driver or passenger side front upper link.
The arms adjust pinion angle and caster, with an adjustable range of 15.25 to 16 1/8 inches. Each arm has a Super-Flex joint with a rebuildable spherical bearing assembly that allows extra articulation off road. The joint is designed to keep on-road handling steady alongside its off-road articulation.
The bearing is greasable, and its non-metallic races help keep it quiet in use. The arms are finished in gray powder coat.
Key features
- Adjusts pinion angle and caster
- Super-Flex joint for articulation
- Rebuildable spherical bearing assembly
- Greasable joint with non-metallic races for quiet operation
- Adjustable range of 15.25 to 16 1/8 inches
- Gray powder coat finish
- Driver and passenger side front upper control arms, sold as a pair
Setting pinion angle and caster
Pinion angle and caster affect how the drivetrain and steering behave under load, so adjustment should be done with the vehicle at its normal ride height. Small changes to the upper link length can shift caster and the driveline angle together. Make each change in small steps and measure after every adjustment rather than setting the arm by feel.
Worn joints can make the setting drift, so check the spherical bearing for play before adjusting. Inspect the bushings, the frame mounts and the boot seals. Greasing the joint after each adjustment keeps it moving freely, and recheck the alignment after the first few drives on the road. Keep the mounting bolts at the correct torque once the setting is locked.
Specifications
| Brand | Rubicon Express |
|---|---|
| Part number | RE3780 |
| UPC | 614901440829 |
| Product type | Front upper control arm, adjustable |
| Position | Front upper tube, driver and passenger side |
| Quantity | Pair |
| Adjustable range | 15.25 to 16 1/8 inches |
| Adjusts | Pinion angle and caster |
| Joint | Super-Flex with rebuildable spherical bearing |
| Lubrication | Greasable, non-metallic races |
| Finish | Gray powder coat |
Vehicle fitment
The product title names the TJ, LJ, XJ, MJ and ZJ Jeep chassis. Using the chassis years, the arms cover the 1997-2006 Wrangler TJ, the 2004-2006 Wrangler LJ, the 1984-2001 Cherokee XJ, the 1986-1992 Comanche MJ and the 1993-1998 Grand Cherokee ZJ. Fitment is based on the product title and description.
Verify your year, model and trim before buying, since JK and JL Wranglers use different chassis.
Installation notes
Adjusting pinion angle and caster changes alignment, so have an alignment done once the arms are set. Grease the joint after installation, since the spherical bearing is greasable.
What’s included
Driver and passenger side front upper control arms, sold as a pair.
