RockJock's greaseable bolts include the grade 8 zerk fitted bolt, 2 flat washers and a stover nut. We use these bolts to grease our Johnny Joint rod ends, but they can be used in numerous applications. This bolt is 9/16 in.-18 thread x 4 in. long.
| Brand | RockJock |
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Reviews from Google
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132 reviews
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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.
JG
James Griffin
Jul 26, 2025
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Customer service is top notch. They answered all of my questions and got me my tracking number for my packages. I just received both of them and the quality is next level. You guys are truly awesome.
LM
Logan Matejek
May 27, 2025
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The parts are a massive improvement over factory. I accidentally ordered the wrong endlinks and they helped me figure out the correct size and sent me new ones.
Definitely an awesome store
AL
Aaron Lake
Apr 27, 2025
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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. 👍 …
GH
Gary Haag
Aug 25, 2025
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Ordered a set of Core 4x4 control arms for my 2006 Jeep TJ. These are some heavy duty quality control arms. Can't wait to get them installed. Great customer service too!
RR
Ryan Rogers
Aug 25, 2025
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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.
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oleg k
Nov 23, 2025
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I recently ordered a set of control arms from Core 4x4, and the entire experience was absolutely top-notch from start to finish. The ordering process was smooth, the parts arrived quickly, and the control arms themselves are extremely high quality—solid construction, great finish, and clearly built to last.
I also want to give a special shout-out to Korby, the guy I spoke with during the process. His customer service was amazing. He went above and beyond to make sure I got exactly what I needed, answered all my questions, and made the whole experience stress-free. You don’t see service like that very often these days.
If you’re looking for high-quality suspension components backed by truly exceptional customer service, I highly recommend Core 4x4. I’ll definitely be buying from them again.
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Paul
Mar 24, 2023
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I've been having trouble with the track bar (on my 2nd gen Dodge) since I installed the 3rd gen Synergy adapter bracket and a 3rd gen stock bar.. oddly, they call it a '3rd gen bracket' and the stock 3rd gen bar doesn't quite fit, making contact with the bracket. I had attempted to clearance the bracket but it was still making contact and I could feel it over large bumps.
I reached out to a lot of companies, but Core 4x4 offered to make a custom bar for the application with adjustability and dual Johnny joints. The first pass on it didn't work but they sent me out another passenger side end that made it fit incredibly well.
This was all done solely over email/descriptions/pictures/measurements.
Bar is super high quality and heavy duty, made in the US by a family owned company and carries a lifetime warranty. The customer service was responsive and superb, and the price was a lot less than I expected.
