Carli Suspension Dodge 3" Unchained 3.5 Long Arm System | 2012–2013 Ram 2500/3500 Diesel 4WD

Is This for You?

• You're building a 2012–2013 Ram 2500 or 2012 Ram 3500 Cummins for serious off-road use — and you've already ruled out leveling kits and short-arm lift systems because you understand what binding geometry does to a truck at full droop.
• You have a professional shop lined up that can bore coil buckets to 4.5", weld rear shock mounts to the frame, and install a fabricated long arm crossmember — this is not a driveway build.
• You want King 3.5" Remote Reservoir fronts and King 3.0" Bypass rears on a platform with 11.25" of front travel and 13.0" of rear travel — and you're not willing to compromise on shock body diameter or bypass tube count to get there.

The Result

• 3.0" front lift / 1.0"–2.0" rear lift with 11.25" front wheel travel and 13.0" rear wheel travel.
• Long arm conversion at 50% greater length than factory short arms — eliminates the bind and caster deviation that short-arm geometry produces at lift.
• King 3.5" Remote Reservoir fronts and King 3.0" 3-Tube/4-Tube Bypass rears — Carli Unchained-spec valving for Cummins diesel platform weight.

Factory Ram 2500/3500 short control arms are designed for a specific arc of travel at stock ride height. At 3" of lift, that arc produces increasing bind through the range of motion — the arm fights the axle instead of guiding it. The Carli long arm system replaces the factory short arms with fabricated units 50% longer, flattening the arc and allowing the axle to articulate through full travel without bind or caster deviation. The King 3.5" Remote Reservoir shock runs a 3.5" body diameter — significantly larger oil volume than a 2.0" or 2.5" shock — which is why the factory coil buckets must be bored to 4.5": the shock body physically cannot fit otherwise. This is not a modification that can be skipped or substituted. The King 3.0" Bypass rear shocks use position-sensitive bypass tubes to deliver a compliant initial stroke for on-road use and a progressively stiffer rate as the shock approaches full compression — the 3-tube and 4-tube configurations differ in bypass circuit count and are spec'd by Carli for this platform. FSP valving throughout is calibrated for Cummins diesel front axle weight — running this system on a gas-engine Ram will produce an oversprung, overly stiff ride that degrades both on-road comfort and off-road control.

Audit Table

Kit Contents

• Fabricated Long Arm System & Crossmember (CS-DLAM-03)
• King 3.5" Front / 3.0" Bypass Rear Shock Package (CS-DUC35SPKG-3-12-D)
• Fabricated Shock Towers — Slide-Over Design (CS-DFST525)
• 3" Linear-Rate Front Coil Springs (CS-DMRC-10-D)
• Adjustable Track Bar (CS-DATB-03)
• Track Bar Drop Bracket (CS-DPRBDROP-10)
• Stainless Steel Braided Brake Lines (CS-DBBL-12-D)
• Front Bump Stop Drops (CS-DFBD-1)
• Fabricated Rear Shock Mounts & Gussets — Weld-On (CS-DRSMKIT-03)

Verified Fitment

✔ 2012–2013 Ram 2500 4WD — Cummins Diesel
✔ 2012 Ram 3500 SRW 4WD — Cummins Diesel

✘ Does NOT fit: 2013 Ram 3500 — not listed in Carli application data
✘ Does NOT fit: Ram 2500/3500 Gas engines — spring rates and shock valving calibrated for Cummins diesel front axle weight
✘ Does NOT fit: Ram 3500 DRW (Dually) — SRW geometry only
✘ Does NOT fit: 2WD Ram 2500/3500
✘ Does NOT fit: 2003–2009 or 2014–2026 Ram 2500/3500 — different suspension architecture; see generation-specific Carli kits
✘ Does NOT fit: Ram 1500 — incompatible platform

Transmission Clearance Note

Verify transmission type before ordering. High Output (Aisin) vs. Standard (68RFE) transmissions may have crossmember clearance differences with the long arm crossmember. Confirm with your installer prior to purchase.

Installation Notes

• Coil Bucket Boring: Factory spring buckets MUST be bored to 4.5" to clear King 3.5" shock bodies. This is a non-reversible fabrication step — professional shop required.
• Rear Shock Mounts: Weld-on installation. CS-DRSMKIT-03 requires professional frame welding. This is not a bolt-on application.
• Long Arm Crossmember: Requires professional alignment of mounting geometry during installation.
• Torsion Sway Bar: This system is optimized for the Carli Torsion Sway Bar. Running factory sway bar links will severely limit suspension travel and compromise system performance.
• Full front-end alignment mandatory post-installation. Long arm geometry changes caster, camber, and toe.
• Torque all fasteners to Carli specification. Re-torque all suspension fasteners at 500-mile break-in interval.
• Professional installation required throughout — long arm fabrication, coil bucket boring, and weld-on rear mounts are not DIY operations.

⚠️ LTL Freight Notice: This item ships via freight carrier on multiple heavy pallets due to size and weight (~450 lbs). Residential delivery is included. Freight carrier will contact you to schedule delivery.

Engineering Question: Have you confirmed your transmission type (Aisin vs. 68RFE), coil bucket boring capability at your shop, weld-on rear shock mount access, and Carli Torsion Sway Bar sourcing? This is a fabrication-level build on a narrow application window — 2012–2013 Ram 2500 and 2012 Ram 3500 Cummins 4WD only. Confirm your full build plan and shop capabilities before ordering.