Synergy Jeep JK/WJ HD Knurled Adjustable Ball Joint Kit
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
Description
Description
Our Synergy Jeep JK / JKU Adjustable Ball Joint Kit has endured over 5 years of development and over 500,000 test miles! This is the last set of ball joints you will ever have to buy with a Limited Lifetime Warranty. Tighten up your steering for good with our patent-pending (# 16/020894) design which is fully adjustable, serviceable, and rebuildable without having to press the ball joints back out of the axle end forging yokes (C's). These ball joints never have to come back out.
Available in knurled and non-knurled versions to fit all vehicles regardless of what type of ball joints were installed previously. Lower ball joint bearing surfaces are CNC machined from 4140 steel, heat treated, induction hardened, and ferritic nitrocarburized to make these the longest lasting, longest wearing ball joints on the market. Kit includes all 4 ball joints to service one Jeep and the adjuster tool for adjusting the preload on the lower ball joints.
Fitment:
| Part # | Description |
|---|---|
| 4127 | 2007 - 2017 Jeep JK / JKU |
| 4127KN | 2007 - 2017 Jeep JK / JKU |
Benefits:
- Fully adjustable and rebuildable lowers are designed to last the life of the vehicle, without ever having to press them out of the inner-c
- On and off road tested for more than 5 years and 500,000 miles providing time tested components you can trust
- Best in class price to performance ratio
- Compatible with all aftermarket axle shafts (including RCV's) with no modifications needed
- Fully greaseable metal on metal ball Joint bearing surface has considerably larger area than stock due to elimination of the inner nylon liner for a longer lasting joint
- Heavy duty, heat treated stud prevents unwanted movement and premature failure
- Improves road manners and corrects sloppy steering
Features:
- Patent Pending Lower Ball Joints are adjustable and rebuildable so they always have the correct amount of preload
- Knurled and non-knurled ball joint housing options to fit any vehicle
- CNC machined lower ball joint surfaces from 4140 steel, heat treated, induction hardened, and ferritic nitrocarburized for extreme wear resistance
- Heavy duty, extra large 4140 steel stud for maximum strength and reliability
- Low profile dust boots are made from thick nitrobutile rubber (NBR) protect the joint from contaminants and eliminate any chance of tearing
- Limited Lifetime Warranty
- Zerk fittings included for trouble-free maintenance
Includes:
Notes:
- Synergy 4119 High Performance Grease recommended
- Knurled ball joints required when replacing knurled ball joints that have enlarged the axle end forging bores
- Non-Knurled ball joints recommended for replacing non-knurled ball joints
- Due to these ball joints being tight tolerance, metal on metal ball joints, proper fitment is critical. Using the wrong style of ball joints can cause significant steering issues. We always recommend installing non-knurled ball joints until non-knurled ball joints are no longer a press fit into the axle end forging bores. If your axle end forging bores have been enlarged to the point that non-knurled ball joints are no longer a press fit, knurled ball joints are required.
- Use of the improper ball joint style for the axle housing voids our lifetime warranty. It is up to the installer to verify the proper ball joint style is being used.
- Compatible with RCV axle shafts
- Rebuild Kits and Replacement Parts Available Here.
Part #: 4127KN
