BDS 6-Inch Radius Arm Lift Kit — Ram 3500 with Factory Rear Air Ride SKU: BDS2106FS | Ram 3500 2013–2018 | 4WD | Diesel | 6" Front / 5" Rear | FOX 2.0 Performance Series | Factory Rear Air Ride Required

A complete 6-inch radius arm suspension lift kit engineered for the 2013–2018 Ram 3500 diesel 4WD — specifically for trucks equipped with the factory rear air ride suspension system. Heavy-duty tubular replacement radius arms mount in the factory location with caster adjustment and OE-style rubber bushings. Diesel-specific progressive rate Pro-Ride coil springs provide the 6-inch front lift. A transfer case indexing ring and high-clearance transmission crossmember address driveline geometry at this lift height. The rear uses a high-strength fabricated lift block with heavy-duty air bag spacers for the factory air ride system and extended U-bolts for a 5-inch rear lift. FOX 2.0 Performance Series shocks front and rear. Supports up to 37-inch tires.

Before ordering: This kit is engineered for Ram 3500 trucks equipped with the factory rear air ride suspension system only — it will not fit standard non-air-ride models. Diesel 4WD only. Confirm your T-case bolt count before ordering: this kit ships with the standard 6-bolt indexing ring (PN 122623). If your truck has the heavy-duty 8-bolt T-case, order PN 122813 in place of 122623. If your truck has a 2-piece rear driveshaft, carrier bearing drop 122405 is required (sold separately). Some vehicles may also require rear driveshaft spacer kit 122007 to maintain adequate rear driveshaft engagement. DRW (dual rear wheel) models: note inner wheel clearance to the upper U-bolt plate on 6-inch kits. Welding equipment and a step drill bit are required specialty tools — confirm your installer has these before scheduling.

Required separately (conditional):

• PN 122813 — 8-bolt T-case indexing ring, required if equipped with heavy-duty 8-bolt T-case (replaces included PN 122623)
• PN 122405 — Carrier bearing drop, required if equipped with 2-piece rear driveshaft
• PN 122007 — Rear driveshaft spacer kit, may be required on some vehicles

Verified Fitment

Component Specifications

Lift Configuration (this SKU):

HD Radius Arms:

Pro-Ride Coil Springs — Front:

Rear Lift — Block with Air Bag Spacers:

T-Case Indexing Ring:

FOX 2.0 Performance Series Shocks (front and rear):

Recommended Tire and Wheel Configurations (trimming may be required):

What Is and Is NOT Included

Included — Front:

• Diesel-specific progressive rate Pro-Ride coil springs (pair)
• HD tubular radius arms (pair)
• Forged drop pitman arm
• Track bar relocation bracket
• Sway bar correction hardware
• Bump stops
• Brake line brackets
• Transfer case indexing ring — 6-bolt standard (PN 122623)
• High-clearance transmission crossmember
• FOX 2.0 Performance Series front shocks

Included — Rear:

• High-strength fabricated 5-inch lift block
• Heavy-duty air bag spacers (for OE air ride systems)
• Extended U-bolts
• FOX 2.0 Performance Series rear shocks

Not included (conditional — may be required):

• PN 122813 — 8-bolt T-case indexing ring (required if equipped with heavy-duty 8-bolt T-case; replaces included PN 122623)
• PN 122405 — Carrier bearing drop (required if equipped with 2-piece rear driveshaft)
• PN 122007 — Rear driveshaft spacer kit (may be required on some vehicles)

This kit will not fit:

• Ram 3500 without factory rear air ride suspension
• Gas engine models
• 2WD models

Critical Compatibility

• Factory rear air ride required: This kit is engineered for Ram 3500 trucks equipped with the OE factory rear air ride suspension system. It will not fit standard non-air-ride models. The rear block and air bag spacers in this kit are designed specifically for the factory air ride system.
• Diesel only: Diesel-specific Pro-Ride coil springs are included. Gas engine models are not supported.
• T-case bolt count — confirm before ordering: This kit ships with the 6-bolt indexing ring (PN 122623) as standard. If your Ram 3500 is equipped with the heavy-duty 8-bolt transfer case, order PN 122813 in place of 122623 — confirm your T-case configuration before ordering.
• 2-piece rear driveshaft: If equipped, carrier bearing drop PN 122405 is required. Confirm your driveshaft configuration before ordering.
• Rear driveshaft engagement: Some vehicles may require rear driveshaft spacer kit PN 122007. Confirm with BDS or your installer if driveshaft engagement is a concern.
• DRW models: On dual rear wheel models, inner wheel clearance to the upper U-bolt plate is a consideration on 6-inch kits. Verify clearance for your specific wheel and tire combination before ordering.
• Welding equipment required: Welding equipment and a step drill bit are required specialty tools. Confirm installer capability before scheduling.
• ADAS recalibration: Required after installation. All recalibration costs are the owner's responsibility.

Installation Notes

Professional installation is strongly recommended. This kit is rated Moderate with an estimated installation time of 6–8 hours. Specialty tools required: step drill bit, drill/bit set, pitman arm puller, and welding equipment. Confirm your installer has all required tools before scheduling.

Verify before beginning:

• Factory rear air ride suspension confirmed present
• T-case bolt count confirmed (6-bolt or 8-bolt)
• Rear driveshaft type confirmed (2-piece requires PN 122405)
• DRW wheel and tire clearance verified if applicable
• ADAS recalibration appointment scheduled

Professional alignment is required after installation. Refer to the current BDS Suspension installation instructions for SKU BDS2106FS for complete procedures, torque specifications, and component-specific instructions.

The Obsidian Take

The BDS2106FS fills the gap left by every other BDS 6-inch kit in this catalog — the Ram 3500 diesel with factory rear air ride. Where standard models use leaf springs or coil springs in the rear, the factory air ride Ram 3500 needs the heavy-duty air bag spacers included in this kit to maintain the OE air suspension function through the lifted ride height. The front is the same radius arm approach proven across the platform: tubular arms, diesel-specific Pro-Ride coil springs, 6-inch lift, T-case indexing, and FOX 2.0 shocks. The T-case bolt count check is the one pre-order detail unique to this kit — 6-bolt is standard, 8-bolt requires PN 122813 instead. Check the T-case configuration before the order goes in.

This Product Is For You If

• You own a 2013–2018 Ram 3500 diesel 4WD equipped with the factory rear air ride suspension system.
• You have confirmed your T-case is 6-bolt standard (kit included) or sourced PN 122813 for the 8-bolt variant.
• You want 6 inches of front lift and 5 inches of rear lift that maintains the factory air ride system function.
• You want FOX 2.0 Performance Series shocks with application-specific valving.
• You want up to 37-inch tire clearance.
• Your installer has welding equipment and a step drill bit.

This Product Is Not For You If

• Your Ram 3500 does not have factory rear air ride suspension — see the standard radius arm or block kit variants.
• Your Ram 3500 has a gas engine.
• Your Ram 3500 is 2WD.
• You have not confirmed your T-case bolt count.
• Your installer does not have welding equipment.
• You want NX2 Nitro Series shocks — see the NX2 variant.
• You want FOX 2.5 Performance Elite Series shocks — see the FOX 2.5 variant.

Product Family Reference

Common Questions

Does this kit work on Ram 3500 trucks without the factory air ride?
No. This kit is engineered specifically for trucks with the factory OE rear air ride suspension system. The included air bag spacers and rear block are designed for that system. For standard suspension models, see the applicable BDS kit for your drivetrain and fuel type.

How do I know if my Ram 3500 has factory rear air ride?
Factory rear air ride is an option on certain Ram 3500 trim and package combinations. Confirm by checking your build sheet, the suspension at the rear axle, or the factory window sticker. If you are unsure, confirm with a dealer before ordering.

How do I confirm my T-case bolt count?
The 6-bolt and 8-bolt transfer cases require different indexing rings. The standard kit includes PN 122623 (6-bolt). If your Ram 3500 has the heavy-duty 8-bolt T-case, order PN 122813 in place of it. Check your build sheet or have a shop inspect the T-case before ordering.

Do I need the carrier bearing drop?
Only if your Ram 3500 has a 2-piece rear driveshaft. Confirm your driveshaft configuration — if 2-piece, PN 122405 is required.

I have a DRW (dually) — does this kit fit?
DRW models are in the BDS fitment data for this kit. DRW owners should verify inner wheel clearance to the upper U-bolt plate on 6-inch kits before ordering.

Does ADAS need to be recalibrated after installation?
Yes. All ADAS sensors require professional recalibration after installation. All recalibration costs are the owner's responsibility.

Manufacturer Data Disclaimer

Fitment, specification, included-component, and installation data for this kit are sourced from BDS Suspension manufacturer documentation and OFAS-verified product data current as of publication. Manufacturer specifications and included components are subject to change without notice; confirm current documentation for this SKU at the time of purchase.

Required Legal, Warning, Fitment, and Return Notices

Fitment Notice: This kit requires the factory OE rear air ride suspension system. It will not fit Ram 3500 models without factory rear air ride. Diesel 4WD only.

T-Case Notice: This kit ships with a 6-bolt indexing ring (PN 122623). Trucks with a heavy-duty 8-bolt transfer case must order PN 122813 in place of PN 122623. Confirm your T-case configuration before ordering.

ADAS Recalibration Warning: This kit alters vehicle ride height and suspension geometry. All advanced driver assistance system (ADAS) sensors require professional recalibration after installation. Schedule recalibration at an authorized dealer or certified ADAS service center. All recalibration costs are the owner's responsibility.

Installation Warning: Professional installation is strongly recommended. Welding equipment and a step drill bit are required specialty tools. A professional wheel alignment is required after installation.

Tire Fitment Notice: BDS references configurations up to 37 x 13.50-inch tires. Trimming may be required. Buyer is responsible for verifying tire and wheel clearance for their specific vehicle and build.

California Proposition 65 Warning: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Return Policy: All returns require prior authorization from Obsidian Forged Auto Supply — do not ship any product back without a Return Merchandise Authorization (RMA). To request an RMA, contact OFAS at Support@obsidianforgedautosupply.com or 469-407-7538 (Monday–Friday 9am–5pm CST, Saturday 9am–3pm CST) with your order number, product SKU, return reason, and photos. Return requests must be submitted within 90 days of delivery. To qualify, the product must be new, unused, uninstalled, complete with all hardware and included components, and in original manufacturer packaging. Do not write on, tape to, or place shipping labels directly on the manufacturer's product box. Return shipping is the customer's responsibility in all cases. Non-defective returns may be subject to a 15% restocking fee. No restocking fee applies when OFAS shipped the wrong item or the return is due to a verified defect or approved damage claim. Some products — including special-order, electrical, and installed items — may be non-returnable. Return eligibility is also subject to applicable manufacturer and supplier return requirements. Approved refunds are issued to the original payment method within approximately 10 business days of the warehouse receiving and processing the returned product. For damaged, missing, or incorrect shipments, contact OFAS within 48 hours of delivery, retain all packaging, and do not install the product.