The Special Sauce:
HOUSING
- SAE 1045 Solid Steel Forged Housing: This is unequivocally the best carbon alloy steel for this application.
- Knurled Housings: The preferred design for aftermarket installations.
- CNC Machined Housing: Make our parts and bearings dimensionally perfect, eliminating any die wear issues.
BALL STUDS
- SAE 4140 Hot Forged Chromoly Ball Studs: For the strongest possible metallurgy.
- Induction Heat Treated Ball Studs: Provides a very precise heat treatment to the exact depth and location we want it.
- UPPER: Plunger Design Stud:Unique to Jeep and allows up and down movement with no side-to-side movement.
- LOWER: Polished Ball Studs: Built like an anti-friction bearing with extremely precise tolerances.
- Rolled Threads: Made by pressing the shape of the threads into the ball stud instead of cutting. This strengthens the threads instead of weakening them and allows for easy movement of hardware. This ain't no Ikea furniture!
- Step Threads: Allows for very easy movement of hardware on install and superior holding when torqued (installer choice).
BEARING DESIGN
- UPPER: Dual Carbon Bearing Design: Used mainly in Jeep and Dodge upper ball joints is the solver of all things wobbly. Like all our products.
- LOWER: Military Grade Acetal Bearing: The same bearing material spec'd by the US military for Hummer ball joints. This material is: dimensionally stable (doesn't expand or contract with hot or cold, water or oil absorption), can be polished smooth as steel, is anti-friction, doesn't wear itself out under load like metal on metal, and can take an absolute pounding.
BOOTS
- CR Rubber Boots: The most durable material for undercar applications. Resistant to deterioration from road level ozone, oil/gas/engine fluids and extreme heat or cold.
- Pancake Boot
FINISH
- E-Coating: Extremely durable electrochemical finishing process
HARDWARE
- Grade 8 - Class 10.9 Hardware: Superior tensile strength.
- Castle Nut: Industry standard where high vibration loads occur.
LUBRICATION
- Pre Threaded Zerk Housing: If you have ever installed a MOOG Ball Joint without a pre-threaded zerk fitting you will understand what a simple but great feature this is. Another installer fav.
- Greaseable: Because it should be.
- Pre-Greased: Just in case you forget, we have you covered.
- Gull Winged Grease Grooves: Allows for improved lubrication disbursement around the ball stud.
- Zerk Fittings: Included for every application.
SPECIAL FEATURES
- Custom Features: UPPER: Custom Bearing design to eliminate Death Wobble.
- Custom Features: LOWER: Angled Zerk housing for easier servicing.
Where It Fits:
Vehicle Position: Front Upper, Front Lower
Quantity per Vehicle: 1
Moog Interchange: K3134T & K3185
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Grand Cherokee | 1999 - 2004 | |
| Jeep | Wrangler | 2007 - 2018 |
| Brand | Apex Chassis |
See It Installed
Install videos and build guides on our YouTube channel.
Watch more installs on YouTubeReviews from Google
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132 reviews
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Ajay Paynter
Mar 4, 2026
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Great company, who worked with me on shipping parts to arrive in time for a show. When I explained my concern they went above and beyond to make it happen. Quality of the parts is top notch.
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Ryan Colligan
Mar 4, 2026
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I have nothing but good things to say about Core 4x4. I have the crawler series on my JKU and we take it all over the place. These parts handle everything we throw at them.
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Marcus Torres
Jan 15, 2026
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Best control arms I have installed on any of my builds. After running every major manufacturer, Core 4x4 is on par or better than all the high-end companies at a fraction of the cost. Lifetime warranty is the cherry on top.
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DSI
Jul 26, 2025
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Great products with excellent customer service after the sale
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DANIEL DUSSAULT
Nov 23, 2025
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Very beefy items for a very reasonable price. Personally have CORE rear track bar and all upper control arms for my 04 Jeep TJ. Had a slight issue with control arm length and they went above and beyond to swap jam nuts to get me where I needed to be. Really have to appreciate a company like this.
AM
Adam M
Sep 24, 2025
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First time buying from Korby @ Core 4x4 and it’s being nothing short of a great experience. I bought the non adjustable Trail kit for my 5th Gen Ram 1500 with a 2” lift. The welds look great, nice powder coat finish and quality bushing. Had some trouble fitting the grease nipples due to the powder coating but a thread tap would fix that. They fit easily and perform great. I felt the improvement straight away. No more wheel hop on hard acceleration which was my main reason for the purchase.
I was missing some smaller bushings needed for the 5th Gen and Korby’s custom service was on point, with responsive emails and mailing out the missing parts straight away. Very happy with their products and customer service. Highly recommended company👌🏽
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Ben
Mar 24, 2021
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2001 Wrangler TJ- i have purchased all front/rear upper/lower control arms. Front track bar and rear track bar. Quality is excellent and extremely durable you can tell its built to last. Bent a bolt on the front track bar and called and spoke with Spence. He immediately sent me out new hardware plus some! Product is amazing but what really separates companies apart is their service and these guys are second to none. Thank you all!
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Ryan Rogers
Aug 25, 2025
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I purchased a set of the Cruiser Series control arms for my Jeep Jk based on postive reviews from different Jeep Facebook pages. Ordered and 2 days later realized they had the very same exact arms on sale in the overstock section. Called them up and they refunded me the savings from my original purchase. Amazing, honest service. Can't wait to get them installed. Keep up the good work guys.
MM
Mike Martinez
Aug 25, 2025
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Phenomenal company - very rare to come by in the automotive industry. Also very impressing. Let me start here. I got a set of yellow sway bar end links for my 19 ram DT (new body style) and let me tell you, I’m hooked. For numerous reasons. One the craftsmanship behind the product is unmatched for sure for without breaking the bank. 2ndly, they stand behind their product. Had a very minor issue and it was resolved in a blink of an eye!!! Insane. Just because of what i listed above i will forever spend my money with core 4x4! And i think you should too! I have no affiliation at all with this company besides being a consumer. I will be ordering my yellow UCAs and the rest of my rear suspension from them here shortly!
Korby on the other hand. The representative that helped me went above and beyond FAST. I hung up the phone with him, and with in no lie 3 minutes he was calling back with an answer. GREAT GREAT GREAT customer service, Korby you and core 4x4 are what give us hope in the car community! With much love and great health to you all!!
BM
Brantly Musgrave
Jan 22, 2026
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First and foremost would like to say that Core4x4s customer service is top notch and they definitely stand behind their warranty on products! Highly recommend using them for any of your off road needs! It’s rare to find a company now a days that backs their products and they do!
Had a few issues with mounts and control arms and they handled it without hesitation! Thank you!