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10.7 - Steering

Type: Full hydraulic steering

Manufacturer: PSC Motorsports

Full hydraulic steering with no mechanical linkage: a PSC pump feeds a PSC orbital steering control valve, which drives a double-ended ram. Ram stroke is limited to Dana 44 spec by Busted Knuckle Off-Road steering stops, and the ram mounts via an Artec Industries Dana 60 ram mount cut down to fit the Dana 44. A Mishimoto fluid cooler with fan (gated by a 180 °F inline thermostat) cools the circuit.1

Component part numbers below come from the PSC FHK400TJ kit — the 1997-2006 TJ/LJ Extreme Series full hydraulic kit with a 2.75" double-ended cylinder (PSC's 40"+ tire kit).2 The orbital valve and cylinder carry over directly; the kit pump is the exception — its PK40JP2-FH bracket is Jeep 4.0L-specific and does not fit this build's Cummins R2.8.

Specifications

Component Specification
Type Full hydraulic (no mechanical linkage)
Kit PSC FHK400TJ (TJ/LJ Extreme Series, 2.75" double-ended)
Steering Control Valve PSC 160cc orbital (in FHA160-S accessory kit)
Ram PSC SC2227K1 (2.75" × 8.0" double-ended)
Pump Cummins-specific PSC pump TBD (kit PK40JP2-FH is 4.0L-only)
Reservoir Remote (included with pump kit) — model TBD
Cooler Mishimoto fluid cooler + fan (180 °F inline thermostat)
Fluid PSC 715 (SWEPCO 715)

System Components

Hydraulic Pump

Pump is engine-specific — the kit pump does not fit. The FHK400TJ kit ships a PK40JP2-FH pump kit built for the Jeep 4.0L accessory drive. This build runs a Cummins R2.8, so the kit pump/bracket does not bolt up — a Cummins-compatible PSC pump must be sourced. The kit's orbital valve and cylinder are engine-agnostic and carry over unchanged.

Specification Value
Manufacturer PSC Motorsports
Model TBD — Cummins R2.8 pump + bracket (NOT the kit's PK40JP2-FH)
Flow Rate TBD
Pressure TBD
Drive TBD (belt vs. Cummins gear-drive)

Steering Control Valve

Specification Value
Type Orbital (PSC)
Model 160cc — supplied in PSC FHA160-S accessory kit

Steering Ram

Specification Value
Type Double-ended (PSC)
Model SC2227K1
Bore 2.75"
Stroke 8.0" native; effective stroke limited to Dana 44 spec via Busted Knuckle Off-Road steering stops
Mount Artec Industries Dana 60 ram mount, cut down to fit the Dana 44

Reservoir

Specification Value
Type Remote (included with PSC pump kit)
Capacity TBD
Location TBD

Cooler

Specification Value
Unit Mishimoto fluid cooler
Fan Mishimoto (matched to cooler)
Control 180 °F inline thermostat
Fan Current Draw TBD (confirm fits PMU Out 8 ~15A budget)
Fan Power Source PMU Out 8 (~15A, thermostat-switched) — see PMU Outputs

Fluid Specifications

Specification Value
Fluid Type PSC 715 (SWEPCO 715)
Capacity TBD (kit ships ~4 qt; confirm system fill)

Outstanding Items

  • Source a Cummins R2.8-compatible PSC pump + bracket (kit PK40JP2-FH is 4.0L-only)
  • Confirm pump drive type (belt vs Cummins gear-drive), flow rate, and pressure
  • Confirm the Dana 44 stroke length set by the Busted Knuckle stops
  • Document Artec Industries ram mount part number and the Dana 44 cut dimensions
  • Confirm remote reservoir model and mounting location
  • Confirm fluid system fill quantity
  • Confirm Mishimoto cooler fan current draw fits the PMU Out 8 (~15A) budget
  • Document hydraulic line routing

  1. Owner decision, 2026-05-30 — full-hydro kit is PSC pump + PSC orbital valve + PSC double-ended ram; Busted Knuckle Off-Road steering stops limit ram stroke to Dana 44 spec; Artec Industries Dana 60 ram mount cut down to the Dana 44; Mishimoto fluid cooler + fan on a 180 °F inline thermostat. Model numbers, bore/stroke values, flow/pressure, and fluid specs remain pending. 

  2. PSC Motorsports FHK400TJ — 1997-2006 Jeep TJ/LJ Extreme Series full hydraulic kit, 2.75" double-ended cylinder (PSC Motorsports / pscsteering.com, accessed 2026-05-31). Kit boxes: FHA160-S (160cc full-hydraulic accessory kit w/ orbital valve), PK40JP2-FH (high-flow pump kit — Jeep 4.0L bracket, not used here), SC2227K1 (2.75" × 8.0" double-ended cylinder); fluid PSC/SWEPCO 715. Smaller-tire variant is FHK100TJ (2.5" bore / 125cc valve, 35-42"). Pump bracket is 4.0L-specific, so it does not fit this build's Cummins R2.8 — valve and cylinder carry over.