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 rear bump stop kit for TJ Wrangler and LJ Unlimited vehicles is the only bump stop on the market that incorporates coil spring retainers to positively attach the top and bottom of the coil springs to the vehicle. This kit extends the top and bottom bump stop impact points the necessary amount for a 4 in. lift. Constructed of quality polyurethane components and billet aluminum spacers, these bump stops mount inside the coil springs. This is a kit for the rearend of the vehicle only.
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Wrangler | 1997 - 2006 | |
| Jeep | Wrangler | 2004 - 2006 |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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Don
Jul 26, 2025
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Great shop, great parts and great service. You want to buy off this company and company’s like this!!!! Wish we had more companies as good as this one!! Thank you
A
Adam
Oct 24, 2025
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I couldn't have been more excited for the initial unboxing of these new Core 4x4 UCA's!
They appear to be so well built and just a true quality product.
Installation was a breeze and the initial testing with the forklift appears to have given me some additional flex with less binding on the rest of the components now that the geometry is back properly aligned.
Time will tell how they hold up on my near future off-road adventures but I don't have any doubt that they are up to the task!
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David
Nov 23, 2025
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First of I just want to say Great customer service korby Has helped me from the start and has not let me down! Reached out to him again today and he was able to warranty some parts out for me.
As far as the quality of the parts.. excellent! The build quality is great. I can definitely tell a
Difference from the cheap oem rear control arms to these and the pan hard bar.
Color, From what I can tell it’s super durable been through a few mud holes on top of the daily road grime and after a quick wipe they still pop!
Overall I recommend. Customer service is everything for me and it’s definitely there at Core 4x4.
JM
Jay Miller
Jul 26, 2025
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I purchased a upper and lower set of control arms from core 4x4 they came early then expected and seem to be very nice quality I ran into a complication installing them and emailed them my question I was expecting to get the response maybe the next day because it was after hours I got a response in about a few minutes which allowed me to finish the project that day I super appreciate that, the products are good strong lifetime warranty and their customer service is top notch
TM
Tony Moller
Aug 25, 2025
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Awesome parts! Support the older Jeeps! Great customer service.
MB
Melody Baker
Jan 22, 2026
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I ordered a part for my 03 Jeep TJ and all I can say is wow! Korby at Core 4x4 is a total rockstar!! There was a glitch with my payment and within minutes, Korby reached out to me to get it fixed, then sent my receipt with the tracking number. I lost the number and reached out to him during the Holidays and got a rapid response with the number again. I can’t say enough about the customer service and the quality of parts. Thank you!!
DD
Dmitriy D
May 27, 2025
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Installed rear and upper control arms and track bar on my 3rd Gen 4RUNNER to align rear axle and restore factory wheel base after 3.5" lift. Car drives better than New! Improved handling cornering and overall driving. Very solid and high quality made product. Support is outstanding. Shipping extremely fast.
Thank you so much. I wish you will have something new for my car.
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. 👍 …
TR
Tim Reigies
Mar 25, 2018
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Received the track bar I ordered, product looks extremely strong, thx core 4x4
BB
Brayden Brockey
Mar 23, 2024
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Got a set of upper control arms for my xj, really impressed with the quality
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Specifications
| Brand | RockJock |
