RockJock Jam Nut, 3/4 in.-16 RH Thread

First off amazing products. I got a set of adjustable control arms for my XJ and it is so nice to be able to dial in caster and pinion angles. A quick call and I was able to purchase an adjustable track.

I had several questions before my purchase and Korby helped me with the correct parts to order and recommendations. Outstanding customer service and product knowledge! Can't wait to install them!

First off: Korby, the gentleman that helped me decide on which kit to go with is EASILY the nicest, and most patient person I’ve dealt with, when ordering parts for this build. Second: the quality of the product is INSANE! These parts are so nicely fabricated, then powder coated for extra longevity, and they even offer an aluminum upgrade in some cases (which I went with, to save weight). Having said all of this, the most impressive thing was the lead time. These parts are build to order, and I literally ordered my suspension one week ago, today! Yes, they built, powder coated, packaged, shipped my suspension components (RAM 1500 Track rear trailing arm full set in 7075 aluminum, and front upper control arms), AND they arrived, all within a week! Granted, that I’m only one state away, but WOW!!! One week?! Amazing! So, in sort: excellent products, which arrived excellently packaged (no damage, an boxes not over-stuffed with heavy suspension parts; three boxes total, as opposed to one super heavy one…my back thanks you), super quickly, and customer service that ANY business would be envious of….so, if you’re in the market, absolutely go with Core 4X4!

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!

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

Excellent service, Prompt responses when needing technical assistance, Amazing looking parts that fit excellently. I would recommend them to anyone looking for suspension components. Also very well packaged when we received the shipment, which means no damage from shipping company!! We went with the Crawl Series double adjustable kit and it definitely looks killer on our build!!!

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.