Made in USA
Orem, Utah
Lifetime Guarantee
Unconditional
10 Colors
In-house powder coat
Fully Adjustable
0-6" of lift
3 X-Series Options
Only Core 4x4
RockJock's forged Johnny Joints for fabricators and suspension system builders offer 30 degrees of unrestricted movement in any direction as compared to 22 degrees on a common heim joint! Johnny Joint rod ends offer cushioning that a heim joint cannot provide via high-density urethane bushings that encase the inner ball. The heat treated center balls are cross-drilled for thru-bolt lubrication and the joint internals are retained with 2 heavy duty, heat treated side washers and a snap ring. This specific joint is designed to fit the axle side of the 2021 and up Bronco's rear control arms and feature a 2 1/2 in. diameter joint body, fitted with a zerk fitting for greasing, 2.3 in. of 1 1/4 in.-12 left hand threads on the shank, and a 70mm mounting width ball with a 16mm thru bolt hole. Finished in gold zinc plating.
| Brand | RockJock |
Reviews of Core 4x4
5.0
★
★
★
★
★
132 reviews
GV
Gil Valk
Sep 24, 2025
★
★
★
★
★
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!!!
MM
MIKE (Mike the Mechanic)
Jul 26, 2025
★
★
★
★
★
Amazing company and customer service!!!! I messed up on my order and the fixed it immediately. Would definitely recommend them. Can't wait to hit the trails with their product.
DA
Dastrup Auto
Mar 25, 2019
★
★
★
★
★
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!
OA
Owen Adams
Sep 24, 2025
★
★
★
★
★
These guys are awesome I messed up my address on my order somehow and they were so so helpful Korby was right there every step to a solution very communicative and respectful I will definitely be ordering parts with them in the future!
AL
Aaron Lake
Apr 27, 2025
★
★
★
★
★
Korby was a great help with getting me a set of leaf springs for my Cherokee. Great customer service and an awesome product all made in the USA. Proud to support and rock their parts on my vehicle. 👍 …
JL
John Luna
Nov 23, 2025
★
★
★
★
★
Great team, and help to support my jeep and provide best stuffs
MT
Ma TheMeatLoaf
Mar 23, 2024
★
★
★
★
★
Their website estimated 2 days to get my parts but actually took 11. No communication to let me know what’s going on. Parts were missing. Some days they answer questions, some they don’t. Didn’t let me know I’d have to alter stock bolts to fit their parts.
All around just seems like they don’t care.
AP
Ajay Paynter
Mar 4, 2026
★
★
★
★
★
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.
PB
Peter Busack
May 27, 2025
★
★
★
★
★
Purchased a set of Trailing arms for my Ram 1500, quality is first class. I bought the ones with the Jonny Joints for more articulation and it appears from the construction I should get a lifetime of use, Zerk fittings are an added plus. Would defiantly recommend, and the the service team answered all of my questions.
AM
Adam M
Sep 24, 2025
★
★
★
★
★
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👌🏽
Your Dynamic Snippet will be displayed here...
This message is displayed because youy did not provide both a filter and a template to use.
Specifications
| Brand | RockJock |
