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  • Steering kit with pump, steering gear, pulley, belt, hoses, cylinder/ram, tie rod clamp, clevis ends, cooler, PSC 715 steering fluid, mounts and hardware on a white background.
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BIG BORE XD® Cylinder Assist® Steering Kit – Jeep Wrangler JK 3.6L (2012-2018)

BIG BORE XD® Cylinder Assist® Steering Kit – Jeep Wrangler JK 3.6L (2012-2018)

$3,490.00
$3,490.00
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Part Number: SK688R36JP1-6.75W-1.25

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

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 Jeep JK/JKU owners who demand serious steering performance. Designed for rigs with locking differentials, aftermarket axles, and tires up to 44", this kit delivers the torque and control you need on the toughest trails.

This complete system 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

4/5

Trail Crusher

Built for challenging terrain with rocks, ruts, and steep inclines.

About:About:

Why you’ll love it

  • Eliminates Steering Play: Tight, precise steering feel.
  • No More Pump Overheating: High-flow pump and fluid cooler keep temps in check.
  • Turns Big Tires with Ease: Increased torque output for 37"–44" tires.
  • Locker-Friendly: Improved turning even with differentials locked.

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 3.6L (2012–2018), 2-door or 4-door
  • Designed for rigs with lockers, aftermarket axles, and up to 44" tires

What’s included

  • BOX 1: SG688R: BIG BORE XD Steering Gear
  • BOX 2: PK36JP1: Complete Pump Kit (Reservoir, Fluid Cooler, Anti-Splash Valve, Serpentine Belt, Brackets, Hoses, Fittings, 4 QTS PSC 715 Fluid)
  • BOX 3: CAK688R-6.75W: Cylinder Assist Kit (Assist Cylinder, Rod Ends, Hardware, Hose Kit)
  • BOX 4: TRCL1.375: Tie Rod Clamp (1.25" ID)

SupportSupport

Installation Video

Installation Video Thumbnail

Overall rating: 2.5 / 5 from 2 reviews.

AI Generated Review Summary

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Reviews

No instructions

"Installing a big bore with hydro assist, 3. 6L 2022 Rubicon, I've looked on the website, forums, YouTube, and nothing relevant for my Jeep, northern has the best but lacks on a jl, one huge problem was having to lift the engine, remove the exhaust to head bolts, cut the alignment spike on the dampener, and pry that out, huge pain when no directions, no torque valves to be found for pump to bracket, just disappointed that paying over 3k and no guidance. We'll see how the rest of this cluster goes"

— Wesley (3/5)

Do NOT buy if you live anywhere COLD. It will fail

"The steering system is great unless you get below freezing. I'm now dealing with the 2nd. . . Yes 2nd failed PSC steering cooler due to freezing temps. The cooler burst out the side AGAIN. I used the recommended cold weather fluid (AC/Delco) and it apparently made no difference. I'm now looking at pulling the front end off of my Wrangler and replacing everything. I'm so frustrated with this I can't be bothered to do this until the spring when I know it won't fail again. Unbelievable."

— Adrian (2/5)

Q&A

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