Carli Suspension Unchained Long Arm 3.0" System | King 3.5" RR Front + King 3.0" 4-Tube Bypass Rear | 11.25" Front Travel | Factory Control Arm Mounts Cut | 2012–2013 Ram 2500 / 2012 Ram 3500 SRW Diesel 4WD | SKU: CS-DUC35-12-D

Verified Fitment

This system fits the 2012 and 2013 Ram 2500 and the 2012 Ram 3500 SRW with a diesel engine and 4WD. The 2013 Ram 3500 is not confirmed for this system — the product page title explicitly states "2012 3500." Confirm 2013 Ram 3500 compatibility with OFAS before ordering.

The Carli Torsion Sway Bar and Full Progressive Rear Leaf Springs are included in the base kit. There is no alternative configuration — no add-a-packs and no extended sway bar links are available for this system.

Verify fitment by text: (469) 407-7538

Does NOT Fit

Verify fitment by text: (469) 407-7538

Component Specifications

What Is and Is NOT Included

Included in base kit:

Not Included:

No checkout options exist for this system. Torsion Sway Bar and Full Progressive Leaf Springs are included and are not substitutable. There are no add-a-pack or extended sway bar link alternatives available.

Critical Compatibility

Installation Notes

Skill level: Expert — professional fabrication shop required. This system requires cutting, boring, and welding. It is the most irreversible installation in the entire Carli session.

Step 1 — Factory control arm mount removal: Factory control arm mounts must be cut off the frame. This is a permanent chassis modification. Carli drop brackets install in the cleared area to house the long arm system.

Step 2 — Factory spring bucket boring: 4" Hole Saw kit (included) bores factory spring buckets for King 3.5" front shocks. Requires drill press or equivalent.

Step 3 — Long arm installation: Long arm system installs into Carli drop brackets. Arms run parallel to ground and are over 50% longer than factory — underbody clearance and frame access required.

Step 4 — Rear shock mount welding: Fabricated rear shock mounts and gusset kit weld into rear frame area. Qualified welder required.

Step 5 — Full suspension assembly: Shock towers, track bar, torsion sway bar, brake lines, bump stops, and leaf springs complete the build.

Post-install alignment: Full front-end alignment is mandatory.

Track bar adjustment: CS-DATB-03 must be set for 3" lift configuration — corrects the axle's ¾" driver-side and ½" rearward shift at this lift height.

Instructions: Not currently available at carlisuspension.com for this SKU.

Required shop equipment:

Common Questions

What is the difference between this system and the 6" Unchained (CS-DUC35-6-03)?
Three primary differences: lift height, rear lift, and long arm approach. The 6" Unchained uses a radius arm drop bracket system that bolts on without modifying the factory control arm mounts — the factory mounts remain intact and the truck can theoretically be returned to stock. This 3" long arm system requires cutting off the factory control arm mounts permanently to install Carli drop brackets. It is irreversible. The 3" system provides 3"–3.25" front and 1.5"–2" rear lift. The 6" system provides 6" front and 4" rear. Front shock travel is 11.25" on this 3" long arm system — actually more travel than the 6" radius arm system due to the long arm geometry's superior travel stroke balance.

My factory control arm mounts need to be cut off. Is that really permanent?
Yes — this is irreversible. The factory control arm mounts are cut off the frame and replaced by Carli drop brackets. There is no way to reinstall factory-equivalent mounts after this modification without significant welding and metalwork. This is the most permanent suspension modification in the Carli lineup. If you plan to sell the truck or need to return it to stock for any reason, do not order this system.

The rear bypass shocks are clicking. Is something wrong?
No — the King 3.0" 4-Tube rear bypass shocks produce audible clicking from the one-way check valves in the external bypass tubes as they open and close during shock travel. This is normal bypass shock operation and is not a defect or sign of failure.

My truck has a 2-piece driveshaft. Do I need anything else?
Yes — a carrier bearing drop bracket is required for 2-piece driveshaft trucks (typically Crew Cab Long Box) to correct the carrier bearing angle at 3"–3.25" of front lift. Without it, vibration and carrier bearing wear result. Add this separately before ordering.

Can I get this system with an add-a-pack or extended sway bar links instead of the full torsion sway bar and full progressive leaf springs?
No — Carli explicitly states there is no option for extended sway bar links or add-a-packs with this system. The Torsion Sway Bar and Full Progressive Leaf Springs are fixed inclusions. This system is configured as-is with no alternative options.

What is the warranty?
Carli provides a limited lifetime warranty against manufacturing defects to the original purchaser, with proof of purchase at Carli's retail price required. Wear items excluded.

The Obsidian Take

This system is for the 2012–2013 Ram 2500 or 2012 Ram 3500 SRW Diesel owner who has committed to building a dedicated off-road performance truck and understands what cutting off the factory control arm mounts means: the truck will never go back to stock front suspension geometry. The long arm system's 11.25" of front shock travel with a 6"–5.25" up/down-travel split is the functional reason for that commitment — it is more balanced and more capable than any short-arm or radius arm system at this lift height, but it comes at the cost of an irreversible chassis modification.

It is not for the buyer who wants to maintain a reversible build — the 2003–2009 6" Unchained's radius arm approach preserves the factory control arm brackets while delivering more lift. It is not for any buyer without a qualified fabrication shop that can cut, bore, and weld. And it is not complete without a rear Full Progressive Leaf Spring and Torsion Sway Bar — which are already included in the base kit, with no alternative configuration offered.

At $13,728 and 457 lb, this is a purpose-built tool for one thing: maximum off-road performance from the 2012–2013 Ram HD platform. Carli recommends a roll cage to match.

Manufacturer Data Disclaimer

Specifications are sourced from Carli Suspension product documentation and authorized distributor data. Actual product specifications, component fitment, lift heights, and year range may vary by specific vehicle configuration, cab style, bed length, engine, and manufacturer updates. Confirm all vehicle specifications and build requirements with Carli Suspension or OFAS before ordering.

Prop 65 Warning

WARNING: This product can expose you to chemicals known to the State of California to cause cancer and reproductive harm. For more information, visit www.P65Warnings.ca.gov.

Non-Returnable Notice

Suspension components are non-returnable once installed. Note: this system requires cutting factory control arm mounts — a permanent, irreversible chassis modification. Confirm model year (2012–2013 Ram 2500 or 2012 Ram 3500 SRW), engine (diesel), drivetrain (4WD), driveshaft type, and full build requirements before ordering. Text (469) 407-7538 with any fitment or build questions before your order is placed.