The SG684 Series gives you the right steering gear for your Jeep Wrangler JK or JKU—whether you're replacing a worn-out factory box or stepping up to a full Cylinder Assist® setup.

At the base level, the SG684 is a brand-new OEM-style replacement that bolts in like stock and restores proper steering feel.

For builds that need more control and strength, the SG684R Cylinder Assist® gears take it further. These units are equipped with PSC’s integrated valve housing and upgraded components to run a hydraulic assist cylinder—giving you the steering authority you need for bigger tires, tougher terrain, and real off-road use.

Features:

• Cylinder Assist® options available for serious builds
• Improves steering feel, control, and consistency
• Includes key seals and hardware to make install straightforward

Heads‑up for installers

• Verify LHD vs RHD before ordering
• Cylinder Assist® gears require a full assist setup (cylinder, lines, pump, and reservoir)
• Proper system bleeding is critical for performance and longevity
• Always check pump condition, fluid, and hoses when replacing a steering gear

Use it with

• PSC Cylinder Assist® kits (for SG684R models)
• Upgraded PSC pumps and remote reservoirs
• Fresh fluid and properly matched steering components

Specs

• Sector Shaft: 36 mm
• Turning Ratio: 16:1
• Piston Assembly: 70 mm
• Input Shaft: JK 3/4 DD
• Cylinder Assist Ports (SG684R ONLY): -6 AN (3/8”)

Specifications

• Adjustable: Yes
• Install Method: Bolt On
• Type: Steering Assist Cylinder
• Color: Black

Warranty: 1 Year Limited

Fitment: JK