RockJock Jam Nut, 1 1/4 in.-12 LH Thread

Outstanding customer service to match the high quality parts. This is the go-to company.

Small business, family owned, made in the USA, lifetime warranty. Purchased Tier 3 control arms and rear track bar for a 2006 Jeep LJ. Simple website and easy to contact over phone and email. I had some technical questions and they were happy to answer them. They allow local pickup and were built to order same week. The order was wrapped and ready when I walked in and even gave a tour of the shop. They abrasive blast all raw materials to achieve a better surface profile for powdercoat to adhere and create a smooth, durable finish. I also noticed several CNC machines and a robotic welder they use for all their parts. A small outfit with a robotic welder? Their concern for quality is obvious and it shows in the parts they make. Very impressed. Happy to do business with these guys.

These guys are great. You can get them on the phone for support. This important and is not always the case with other custom parts builders. Their control arms are bomb proof and offer plenty of options. You can get real genuine Currie Johnny joints without paying the price for Currie arms.

Good company, they offer well built parts and Great customer service. I had a couple of hang ups with my control arms that I purchased, they were very easy to work with and found the solution to make them work.

Great Experience. I wanted to make changes to my order and Korby was more than willing to work with me to get everything corrected. Hope to deal with these guys again in the future.

I have bought a bunch of sets of arms, track bars and even had custom work done by Core 4x4. Just yesterday, Spence and Cam delivered an awesome cross member they designed and built for me! All of their products have been exceptional! I have personally seen their progression with design changes/updates. They truly take pride in their work and products. Quality control is second to none! They’ve also helped me diagnose issues with different jeeps I’ve had, as well as Dodge/Rams. These guys know their stuff! Really! I trust them whole heartedly and absolutely love their products/quality of work! I’ve referred many people, and will always continue to do so. Keep up the good work Core4x4!

These guys are awesome!! They have helped me build multiple jeeps from zjs to mjs and now with my lj build they all ways impress. There products are the best on the market in my eyes. The best part about it all is it's all made right here in american and shipped anywhere in the world 🌎 . Don't think twice when your looking for control arm or lift kits for your vehicle if these guys sell it BUY IT!!!