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BIG BORE XD® Cylinder Assist® Steering Kit – Jeep Wrangler JK/JKU 3.8L (2007–2011)

BIG BORE XD® Cylinder Assist® Steering Kit – Jeep Wrangler JK/JKU 3.8L (2007–2011)

$3,490.00
$3,490.00
Sale Out of Stock
Shipping calculated at checkout.

Part Number: SK688R38JP1-6.75W-1.25

Axle Type
Lock-to-Lock Stroke
Tie Rod Clamp Size

If you’re running lockers, big axles, and 40s on your JK, your factory steering isn’t going to cut it. PSC’s BIG BORE XD Cylinder Assist Steering Kit is the ultimate upgrade for 2007–2011 Jeep Wrangler JK/JKU 3.8L owners who demand serious steering performance. Built for Jeeps with locking differentials, aftermarket axles, and tires up to 44", this kit delivers the torque and control you need on the toughest trails.

Every kit includes our BIG BORE XD Steering Gear, a high-performance pump kit with remote reservoir, a Cylinder Assist kit, and all the hardware you need for a clean install. Say goodbye to steering play, pump overheating, and white-knuckle turns when your lockers are engaged.

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PSC TRAIL SCORE

5/5

Extreme Off-Road

Engineered for the toughest trails and extreme rock crawling.

Tech InfoTech Info

Heads‑up for installers

  • For supercharged vehicles, call PSC for a custom pump kit.
  • Use HWK-688-PP hardware kit when installing with a Synergy MFG Track Bar and Sector Shaft Brace.
  • Some aftermarket track bars may not clear the BIG BORE XD gear—check before install.
  • Recommended tools: 

46MM Pitman Arm Nut Socket 

Pitman Arm Puller 

Tie Rod End Puller 

Axle Caster Gauge 

Pneumatic Anaerobic Thread Sealant 

Fitment

  • Jeep Wrangler JK 3.8L (2007–2011), 2-door or 4-door 
  • Designed for rigs with lockers, aftermarket axles, and up to 44" tires

Ideal for

  • Hardcore off-road builds 
  • Rock crawlers and overlanders 
  • JK owners tired of fighting the steering wheel

Specs

  • Lock-to-Lock Stroke: 6.75", 7.5” or 8.0"
  • Tie Rod Clamp Sizes: 1-1/4", 1-3/8", 1-1/2", 1-5/8", 1-3/4", 2.0", or No Clamp
  • Axle Type: Standard or OE Axle
  • Steering Gear: BIG BORE XD
  • Pump Kit Includes: Reservoir, Fluid Cooler, Anti-Splash Valve, Serpentine Belt, Brackets, Hoses, Fittings, and 4 QTS PSC 715 Fluid
  • Assist Cylinder: 1.75" x 6.75" (No-Weld, Bolt-On)

What’s included

  • BOX 1: SG688R BIG BORE XD Steering Gear
  • BOX 2: Complete Pump Kit
  • BOX 3: Cylinder Assist Kit (Cylinder Assist, Bracket, Hose Kit, Rod Ends, Tie Rod Clamp)
  • BOX 4: Fluid Cooler and PSC 715 Power Steering Fluid

SupportSupport

Install Instructions

California Prop 65 Warning

California Prop 65 Warning

This product can expose you to chemicals including lead and di (2-ethylhexyl) phthalate, which are known to the State of California to cause cancer, birth defects or other reproductive harm.

For more information, go to www.P65Warnings.ca.gov