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.
- 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 Thread: Allows for very easy movement of hardware on install and superior holding when torqued (installer choice).
BEARING DESIGN
- UPPER: 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
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
XRF Interchange: K3134TX & 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 YouTube
Reviews from Google
5.0
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132 reviews
AP
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.
RC
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.
MT
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.
LS
Leonard Smith
Jan 22, 2026
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I don’t write reviews often, but Core 4x4 absolutely earned this one.
I recently ordered leaf spring mounts and realized after the fact that I messed up my order. Totally my mistake. Instead of giving me the runaround or pointing at a return policy, Core 4x4 emailed me back and forth, worked through exactly what I was doing with my build, and made sure I ended up with the correct parts.
That kind of customer service is rare these days — especially in the off-road world where a lot of companies stop caring once the order is placed.
The parts themselves are exactly what you hope for: solid, well-made, confidence-inspiring hardware that looks like it belongs under a vehicle that actually gets used. You can tell these are designed by people who understand suspension geometry and real-world abuse, not just CAD screenshots.
Mistakes happen — especially on custom or modified builds — and Core 4x4 handled mine like pros. Fast responses, clear communication, and a genuine effort to help me get it right.
If you’re on the fence: don’t be. Core 4x4 is the kind of company you want backing your build — the kind that treats customers like fellow enthusiasts, not order numbers.
GM
George Mar
Sep 24, 2025
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Great company. Highly satisfied with Core 4x4 customer service. Had some bushings fall apart around 600 miles from home. Called and spoke with Korby Linscomb on Thursday, late in the afternoon. He was able to get my bushings sent across country overnight at a very reasonable rate. Had me up and running by Friday evening with enough time to enjoy the Great Smoky Mountain Jeep Invasion. Thanks Guys!
NM
Noah Myers
Mar 23, 2024
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I contacted these guys on a Saturday through email and needed some control arms by the following weekend, Spence got back with me and told me he would make sure the order got shipped out on Monday, they got busy and wasn’t able to ship the package out so he got back with me that evening and upgraded my shipping for free and shipped out the next day, only because he told me he’d make sure I’d have them by the weekend! This company sticks to their word! The customer service from these guys are unmatched and they will have another lifetime customer here!
RM
R2d2 Movi78
Feb 21, 2026
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I’m extremely impressed with Core 4x4. The quality of their parts is outstanding — everything feels solid, well‑built, and engineered with real attention to detail. Shipping was fast and everything arrived perfectly packaged. Their customer service is just as good as their products: responsive, helpful, and genuinely committed to making sure you get exactly what you need.
Overall, a top‑tier experience. I’ll definitely be buying from them again. Specially thank you Mr. Linscomb from Core 4x4. Arturo M.
HK
Harold Kruder
Mar 23, 2024
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I needed some parts and had to replace 1 lower control arm and their customer service is great. Helped with answering my questions and got parts shipped quickly.
K
Korosunagi
Jul 26, 2025
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I broke a grease fitting off in my end link. I thought I was going to have to buy a new one. Reached out to Core 4x4 and wham! bam! They fixed it and sent it back with 2 day shipping. Got it a day early even. If they couldn't fix it they were going to send me a new one. Now that's customer service! They are now a permanent part of my garage.
Thank you Core 4x4!
DW
Darin Wuebbels
May 27, 2025
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Thanks for the fabulous customer service. Your products and customer service are first class. I highly recommend these guys. Excellent experience.
