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User Media for: PSC Big Bore Steering Gear - JK

Suspension
Steering
Hydraulic Steering Kits >PSC Big Bore Steering Gear - JK

PSC Big Bore Steering Gear

Name: PSC Big Bore Steering Gear
Brand: PSC
SKU: SG688R
Price: 1450 USD
Availability: InStock
Rating: 5 (4 reviews)

JK

Read 4 Reviews | 4 Q&As

Part # SG688R

$1,450.00

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Product Resources

Customer Reviews (4)

Questions (4) Answers (4)

Customer Photos and Videos

Fitment Details

Features & Product Details

The stock JK steering box? It’s fine for stock tires and errands. But throw on 37s, a locker, and a weekend in Moab, and that thing’s begging for mercy. The BIG BORE XD is the fix—built with a beefy 45 mm sector shaft and a reinforced case so it won’t twist, crack, or cry when you crank it hard. Pair it with a PSC High-Flow Pump Kit and you’ll feel the difference the first time you turn the wheel—smooth, strong, and no more arm wrestling at the trailhead.

Features:

45mm sector shaft – nearly 30% bigger than stock for serious strength

16:1 ratio with 80mm piston – more torque, better road feel

Includes PSC proprietary Pitman arm – no guessing, no mismatched splines

Bolt-on upgrade – fits JK/JKU with factory mounts

Handles 35s without assist – and Cylinder Assist® makes it unstoppable

Specs:

Sector Shaft: 45mm (stock is 35mm)

Gear Ratio: 16:1

Piston Size: 80mm

Ports: Metric O-ring (PSC includes adapters in kits if needed)

Case: Reinforced mounting pad and housing

Weight: ~57 lbs

Includes: PSC proprietary Pitman arm

Heads‑up for installers

Weight warning: This gear tips the scale at ~57 lbs. Use a jack or a buddy.

Track bar brace caution: If you’re running a Synergy MFG

Front Track Bar Brace (or similar), you must add PSC HWK-688-PP Bolt Kit (110mm). Using factory or PSC 100mm bolts can crack the case.

Pump matters: This gear needs a pump that can deliver ~1650 PSI and 50% more flow than stock. PSC pump kits are tuned for it.

Bleed it right: Front tires off the ground, engine off, cycle lock-to-lock, then recheck fluid.

Pitman arm note: Supplied arm has no extra drop. Some setups may need a drag link flip kit for proper geometry.

Recommended Tools:

46mm Pitman Arm Nut Socket
Pitman Arm Puller
Tie Rod End Puller
Axle Caster Gauge
Pneumatic Anaerobic Thread Sealant

Improved Steering Power & Heavy-Duty Capabilities If you need more steering power for your Jeep JK, this PSC Big Bore Steering Gearbox is the solution. The PSC Big Bore is one of the most powerful and strongest replacement steering gearbox on the market for the Jeep JK, making it a no-brainer for any off-road enthusiast. This gearbox is designed to accommodate larger tire sizes, larger axles, and locking differentials without sacrificing performance. Featuring a larger sector shaft output of 45mm when installed, your Jeep will be able to handle the extra torque output without compromise. Heavy-Duty Construction & Bolt-On Installation The PSC Big Bore Steering Gearbox carries a larger 85mm piston assembly and can produce up 35% more turning force for your vehicle. This results in easily turning tires of up to 37 inches, making sure your heavy-duty build will function properly. Moreover, the gearbox is crafted from a heavy-duty case with premium hardware components for maximum strength and long-lasting utility. The mounting areas have also been beefed up to handle the hardcore demands of increased steering force. Installation is made simple and straightforward as this steering gearbox bolts directly to your existing mounting points. Best of all, this kit is backed by a 1-Year Manufacturer Warranty to help keep your investment protected.

Product Resources

Customer Reviews (4)

Questions (4) Answers (4)

Customer Photos and Videos

Fitment Details

Specifications

Brand: PSC

Install Method: Bolt On

Color: Black

Mfgr. Warranty: 1 Year Warrranty

Condition: New Product

Return Policy:

Standard

REVIEWS & CUSTOMER MEDIA

4 Reviews

5 out of 5 Stars

5 Stars

(4)

4 Stars

(0)

3 Stars

(0)

2 Stars

(0)

1 Stars

(0)

Customer Photos and Videos

PSC Big Bore Steering Gear ( Part Number: SG688R)

Best Upgrade Ever111 1 year ago

5out of 5stars

More jeep stuff
When my standard JKU box started to fail, I worked with Northridge to identify all of the parts necessary for the upgrade. We went with the ports for the RAM but I have not installed that yet. Been running big bore for a while and it makes 37s seem like stock tires.

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PSC 2 years ago

5out of 5stars

Miguel
I just installed a PSC steering box from Northridge on my Jeep, and it’s a total game-changer. The steering is so smooth now that I can literally turn the wheel with one finger! I seriously wish I’d done this upgrade a long time ago. If you’re on the fence, just do it—you won’t regret it!

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Beef! 4 years ago

5out of 5stars

Joe
This thing is absolute beef.

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3 of 3 people found the following review helpful

Makes Turning 38's Easy 6 years ago

5out of 5stars

Power Steering Upgrade
After upgrading my axles to UD60 and adding 38x15.5 tires I installed the PSCBig Bore Steering Gear, Ram Assist., and inline power steering fluid cooler. It wasn't a terribly difficult install, but the gear box is a beast and very heavy, the hardest part was holding it in place while I started the first bold. Turning my large tires is actually easier than when it was stock with 33's. I would definitely recommend this setup to anyone going 37's or bigger.

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QUESTIONS & ANSWERS

Q: in a 2018 jeep jl 7k Shop2 years ago
With either of the two steering boxes do I still need to change the steering pump ? When installing either of the two PSC steering boxes, you would also need to change the pump with either of these two?
- 0 of 0 people found the following answer helpful
  A: Yes, when going to a PSC box, you need to upgrade to the pump as well so the box gets enough fluid. The stock pump will not have enough pressure, and eventually will starve the box. Thanks
  Northridge Chris @ Northridge4x4 2 years ago
  
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Q: Psc688 Ryno5 years ago
What is the difference between the 688 and 688r? Can I still use the 688 with assist?
- 1 of 1 people found the following answer helpful
  A: The 688 R comes ported, so you could add hydro assist later if you decided to. The 688 is still the big bore box, just doesn't have the ports.
  Northridge Chris @ Northridge4x4 5 years ago
  
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Q: Upgrade steering box pineda4x45 years ago
If I upgrade steering box to big bore box will I need to upgrade the power steering pump as well?
- 0 of 0 people found the following answer helpful
  A: Yes, you should upgrade the pump as well.
  Northridge Chris @ Northridge4x4 5 years ago
  
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Q: SG688R Falco5 years ago
Is there a cylinder assist kit to this model on a 3.8L JKU model? Would I need to buy in pieces to make the kit?
- 0 of 2 people found the following answer helpful
  A: This steering box works with all Jk models.
  Northridge Chris @ Northridge4x4 5 years ago
  
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