RockJock Jam Nut, 1 in.-14 RH Thread

Top notch company. Mechanic lost bolts that clamp upper control arms. Korby sent out spare bolts no charge. Best customer service I’ve come across in a long time. Only suspension brand I’ll ever use.

Great quality control arms and great customer service. Korby has been a great help at answering my questions on some issues I’ve been having with installation!

I have recently come to know Core 4x4 when I purchased a Jeep XJ and was looking for a place that had dedicated XJ suspension and components. Here is what makes them different than most other shops. All of their components are top shelf quality and they back it up if you break any of it. I was able to see their shop when I picked up an order locally and was impressed with their attention to detail and how they assemble and powder coat each part. I had an issue with a shackle and needed the threaded shaft to be shorter. I called in and talked to Kaden and he told me to come by and they would shorten it for me. When I got there, Kaden and Spencer (the owner) met me and talked about options and proceeded to make the right adjustments to fit my XJ. Told me if anything changes in the future and I need additional length, they would take care of me. So what really sets them apart from others is their Customer Service. Try calling in to any other Jeep suspension or part shop and see how they treat you. Been there - done that. Will continue to do business with Core and their team. Getting that kind of service for just a shackle has me thinking I may need to replace my JT components with Core's. Thanks Guys for being helpful good humans!

I ordered the jeep xj long arm lift kit. Control arms showed up first they turned out amazing!! Had some issues with the powder coating on the cross member and sent korby and the team at core4x4 an email. They got right on making me another cross member and sending it out. I appreciate all the help they've given me along the way. Very fast response thru emails. Build quality seems to be pretty dang nice!! Can't wait to install it and enjoy it!

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.

Got a set of upper control arms for my xj, really impressed with the quality

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.