EQ Systems AJ 1/20 Hydraulic Trailer Jack | Single Leg | 8,000 lbs | Screw Drive Override

Lift and level your gooseneck horse or motorsports trailer with the EQ Systems AJ 1/20 Single-Leg Hydraulic Jack System with Screw-Drive Manual Override — a complete single-leg hydraulic lifting system that bolts to the center tube of a gooseneck trailer, featuring the lighter-duty 3.5" × 3.5" tube-in-tube AJ-series jack, 20" stroke, and 8,000 lbs lifting capacity. Weatherproof keyed switchgear standard. Available at The RV Surplus.

Fitment critical: Verify compatibility before ordering. Call EQ Systems at 800-846-9659.

⭐ 8,000 lbs Lifting Capacity — Single Leg

• One AJ-series 3.5" × 3.5" tube-in-tube leg (lighter-duty than AM 4"×4")
• 20" stroke
• Bolts to the center tube of a gooseneck trailer

⭐ Weatherproof Keyed Control

• Weatherproof switchgear with rocker switch and key standard
• Prevents unauthorized use

⭐ Screw-Drive Manual Override

• If power fails, drive the pump with a reversible drill through the override shaft (top center of motor)
• Remove pump cover then foil seal to access
• Use a 6mm (1/4") Allen hex key
• Clockwise retracts, counter-clockwise extends
• Drill must reach at least 2000 RPM for adequate pressure
• Take care not to contact wires or hoses with the drill

What's Included (8420UPS)

• One AJ-series 20" stroke jack
• Commercial single-function pump with screw-drive manual override
• Steel pump cover
• Weatherproof keyed switchgear
• Universal mounting brackets
• Wire harnesses in PVC high-temperature nylon braid

What's Not Included

Ships without fluid (uses Dexron III ATF) and without mounting bolts (bolt kits available separately).

Battery Requirements

Load-test the battery before installing. EQ Systems requires a minimum of 150 amperes at 10.5 VDC for at least 30 seconds. Keep terminals tight and free of corrosion.

Fluid and Maintenance

Runs on Dexron III ATF, filled to about 1" below top of reservoir with jack fully retracted (level rises as jack retracts). Reservoir must run with its vented breather cap fitted, not the flush shipping plug, or the jack will operate erratically. Inspect every 12 months.

Service Parts

• AJ 70 Cylinder — replacement hydraulic cylinder
• Wireless Remote #7823 — optional wireless remote for single-function jacks
• Verify parts against the ID charts or call 800-846-9659

Documents

• EQ Systems Lifting Systems for Any Size Trailer (PDF)
• AJ Single Leg Installation and Operation Manual, EQ004R10 (PDF)
• Single Leg Trailer Jack Troubleshooting Guide (PDF)
• Hydraulic Cylinder Identification for Tube-in-Tube Jacks (PDF)
• Parts Identification Charts
• Required Maintenance Items for EQ Hydraulic Jacks & Slide Systems (PDF)

Other AJ Trailer Jack Options

• AJ 1/24 Screw Drive — longer 24" stroke, single leg
• AJ 2/24 Jack System — dual-leg AJ version
• AM 1/24 Screw Drive — heavier-duty AM series (4"×4", 12,000 lbs)

Recommended Add-Ons

• Solar Panel Kit for AJ Jacks (70487) — keeps jack battery topped up between trips
• Stay Charge with Jumper Cables (8427) — charges trailer battery from tow vehicle
• Stay Charge (8400) — base battery maintainer

1-Year Warranty

Backed by EQ Systems' 1-year manufacturer warranty. Check your operation manual for full terms.

Specifications

• Brand: EQ Systems
• Model: AJ Single-Leg Hydraulic Jack System with Screw-Drive Override
• SKU: 8420UPS
• Series: AJ tube-in-tube (3.5" × 3.5")
• Legs: 1
• Lifting Capacity: 8,000 lbs
• Stroke: 20"
• Tube Size: 3.5" × 3.5"
• Manual Override: Screw-drive output shaft (6mm/1/4" Allen)
• Control: Weatherproof keyed rocker switch
• Fluid: Dexron III ATF (not included)
• Mounting Bolts: Not included (bolt kits sold separately)
• Battery Requirement: 150A minimum at 10.5V for 30 seconds
• Wiring: PVC high-temp nylon braid
• Warranty: 1-year manufacturer warranty