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
Details
Core 4x4's Crawl Series rear upper control arms replace the worn factory stamped-steel arms on the GMC Yukon 1500 (2000–2006). The factory arms use soft rubber bushings and a fixed length, so there's no way to correct pinion angle after a lift or leveling kit. These Core 4x4 arms are a serious step up: DOM steel tubing and forged Rock Jock Johnny Joints at both ends for maximum articulation, with adjustable length to set rear pinion angle back to spec.
Includes: Rear upper control arms (pair); mounting hardware (bolts, nuts, and washers).
Specs:
- Tubing — 1.5 in. o.d. × 5/16 in. wall DOM steel
- Joints — forged Rock Jock Johnny Joints, both ends (double-threaded)
- Adjustable length — for pinion-angle correction
- Lift range — 0–6 in. and up
- Made in the USA
- Lifetime warranty — bend it or break it, we'll replace it
- Wear items (bushings, joints) — covered for 18 months
Suspension Type — Standard or Autoride (Z55): Select at checkout. Z55 trucks have factory rear air leveling; the Autoride version includes the ride-height sensor mounting tab on both rear upper arms. If you're not sure which you have, check the RPO sticker in the glove box for a Z55 code.
Notes:
- Hardware is included with your arms. If you ever need replacements down the road, the matching kit is available separately.
- Running a lift? The 4-piece rear set (CRL-G-800-YUK-RS4) adds the matching lower arms to replace all four rear arms in one job.
Parts:
- Forged Rock Jock Johnny Joint, right-hand — CE-9112N-22 (1 per arm, 2 for the pair).
- Forged Rock Jock Johnny Joint, left-hand — CE-9112NL-22 (1 per arm, 2 for the pair).
- Replacement hardware kit — CRL-G-800-RU2-HWK.
Fits:
- Chevy Tahoe (2000–2006)
- Chevy Suburban 1500 (2000–2006)
- Chevy Avalanche 1500 (2002–2006)
- GMC Yukon / Yukon XL 1500 (2000–2006)
- GMC Yukon Denali / XL Denali (2001–2006)
- Cadillac Escalade / ESV / EXT (2002–2006)
- 1500-series only. Does NOT fit 2500-series HD.
Built With
Tubing: 1.5" OD, 5/16" wall DOM · Joints: Rock Jock Johnny Joints, both ends
| Make | Model | Submodel | Years |
|---|---|---|---|
| GMC | Yukon 1500 | 2000 - 2006 |
Construction & Materials
Tubing: 1.5" OD, 5/16" wall DOM · Joints: Rock Jock Johnny Joints, both ends
| Brand | CORE 4X4 |
| Color | Black or Blue or Charcoal or Green or Light Green or Orange or Purple or Red or White or Yellow |
| Lift Size | 0" — 6" or 6"+ |
| Series | Crawl Series |
| Suspension Type | Standard or Autoride (Z55) |
Use the vehicle selector on our website to shop by your year, make, and model. On product pages, use the kit builder to select your color, series, lift height, and any add-on options, then add to cart. If you need help, call or email our team.
Standard orders typically ship within 1–3 business days of ordering. Custom color orders take approximately 5–10 business days. Because everything is built in-house, we can turn orders quickly even for custom specifications.
You can reach our team through the contact form on our website, or browse to the Contact Us page. Our team is available to answer pre-sale and technical questions before and after your purchase.
Reviews of Core 4x4
5.0
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132 reviews
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R and H H
Oct 24, 2025
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Top notch company. Mechanic lost bolts that clamp upper control arms. Korby sent out spare bolts no charge. Best customer service I’ve come across in a long time. Only suspension brand I’ll ever use.
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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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luke
Mar 24, 2021
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Excellent quality product and service. My l lower control arms broke and within the same day core 4x4 hooked me up with tier 2 arms and with the color I wanted. My Jeep rides better and has been solid for several months so far. 10/10 would recommend their products to anyone.
FS
Fernando Salazar
Aug 25, 2025
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Great quality control arms and great customer service. Korby has been a great help at answering my questions on some issues I’ve been having with installation!
MD
Mark DiGrappa
Apr 27, 2025
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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!
RH
Rex Hodges
Jun 26, 2025
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After ordering an upper and lower adjustable control arm kit manufactured by CORE 4X4 from a jeep parts distributor who's intials are E.T., they came with 3 of the threaded ends missing. After over 2 months of phone calls and emails to this E.T. company nothing was resolved. I finally decided to call CORE 4X4 myself and tell them my dilemma. I spoke with a very personable and professional gentleman named Korby, who is one of CORE 4X4's representatives, after a brief discussion of what I went thru he simply asked me for a picture and some measurements and the items I was missing and asked if I could cover ONLY the cost of shipping and I had my missing parts in exactly 1 weeks time. This company not only builds all it's parts in the U.S.A., they stand behind their products with great customer service and life time warranty. My experience with this company and their Rep Korby was fantastic. I would definitely recommend CORE 4X4 to anyone who needs parts for any 4x4 projects. You just can't beat their quality and service.
Rex Hodges
Valparaiso, Indiana
SH
Shawn Hooten
Apr 27, 2025
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Great products, shipped the next day during a big sale event. Core 4x4 gets it right and gets it done! Thank you all.
LS
Leonard Smith
Jan 22, 2026
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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.
PB
Peter Busack
May 27, 2025
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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.
BA
bryan angell
Jun 26, 2025
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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.
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Specifications
| Color | Black, Blue, Charcoal, Green, Light Green, Orange, Purple, Red, White, Yellow |
| Lift Size | 0" — 6", 6"+ |
| Suspension Type | Standard, Autoride (Z55) |
| Brand | CORE 4X4 |
| Series | Crawl Series |
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