BDS 6-Inch Radius Arm Lift Kit | FOX 2.5 Performance Elite | Ram 3500 4WD Diesel 2013–2018 | SKU: 2104FPE

The BDS 2104FPE is a 6-inch radius arm front lift kit with FOX 2.5 Performance Elite external reservoir shocks for the 2013–2018 Ram 3500 4WD diesel — the DS-generation platform. Heavy-duty BDS radius arms replace the factory arms, correcting caster at lift height and reducing bushing bind. Diesel-tuned front coil springs deliver 6 inches of lift at the correct spring rate for the Ram 3500 diesel's front-end weight. FOX 2.5 PE external reservoir shocks deliver advanced valving and heat-managed damping for sustained towing and off-road performance — critical on a diesel tow rig running sustained high loads where a standard shock body fades.

This kit has three hard fitment splits before it applies to your truck.

First — generation: the 2013–2018 Ram 3500 is the DS platform. The 2019 and newer Ram 3500 is the DT platform — a completely different front suspension architecture. If your Ram 3500 is a 2019 or newer, order 1683FPE (with overload leaf) or 1682FPE (no overload leaf) for the DT platform. The 2012 and earlier Ram 3500 is not compatible with this kit.

Second — engine: diesel-tuned coil springs. Ram 3500 gas requires a different kit — gas and diesel springs are not interchangeable.

Third — drivetrain: 4WD only. Ram 3500 2WD is not compatible.

This kit does not fit the Ram 2500. For the 2014–2018 Ram 2500 4WD diesel at 6 inches with FOX 2.5 PE, see 2100FPE. For FOX 2.0 shocks on this same platform, order 2104FS.

Component Specifications

What Is and Is NOT Included

Critical Compatibility

Three fitment confirmations required before ordering.

Want FOX 2.0 instead of FOX 2.5 PE? Order 2104FS.
Not sure which Ram 3500 generation you have? Text (469) 407-7538 before ordering.

FOX 2.5 PE vs. FOX 2.0 — Which Shock Do You Need?

DS vs. DT Generation Reference — Ram 3500 Diesel

Tire Clearance

At 6 inches of front lift on the 2013–2018 Ram 3500 diesel platform, typical fitment runs 37–40-inch tires depending on wheel offset and backspacing. Tires at the larger end of this range may require trimming or additional modifications. Confirm maximum tire diameter and wheel specifications with your wheel and tire supplier before ordering.

Installation Notes

Professional installation is required. A 6-inch radius arm lift on a diesel platform requires a qualified suspension shop with experience on heavy-duty truck platforms. Do not attempt DIY installation.

Full front-end alignment is mandatory after installation. Do not drive on public roads before alignment is completed. At 6-inch lift on the diesel platform, correct alignment is critical for tire wear and steering geometry under towing load.

Driveline inspection is mandatory at 6-inch lift. At 6 inches, driveshaft angles change significantly from factory. Inspect U-joint operating angles after installation and confirm they are within acceptable range before towing. Driveshaft modification may be required depending on your specific configuration — confirm with your installer before the job begins. On a diesel towing platform at this lift height, this is not optional.

External reservoir routing. Follow BDS and FOX installation instructions for reservoir placement. Avoid pinch points, heat sources, and moving components during routing. Improper reservoir placement can damage the reservoir line and void the FOX warranty.

Torque all fasteners to BDS specification. Torque specs are included in the BDS installation instructions. Do not estimate torque values on a diesel-weight platform.

FOX shock break-in period. Allow FOX 2.5 PE shocks to complete the manufacturer-recommended break-in period before aggressive off-road or heavy towing use.

Text (469) 407-7538 to confirm engine, platform, and drivetrain before ordering.

The Obsidian Take

The BDS 2104FPE is the correct kit for the 2013–2018 Ram 3500 4WD diesel owner who wants 6 inches of front lift with corrected radius arm geometry and maximum shock performance. The FOX 2.5 PE external reservoir is the reason to choose this kit over 2104FS — the reservoir separates the oil from the nitrogen gas charge, managing heat under sustained off-road terrain and heavy diesel towing loads so damping performance stays consistent where a standard shock body begins to fade. On a diesel tow rig that regularly puts sustained load on the front suspension, the 2.5 PE earns its price difference.

If your use case is primarily daily driving and moderate towing and the FOX 2.0 price point covers your application, order 2104FS. The geometry correction and spring package are identical — the shock is the only variable.

If your Ram 3500 is a 2019 or newer DT platform, the DS kit geometry does not apply — order 1683FPE or 1682FPE based on your overload leaf configuration. If it is gas, diesel-tuned springs are the wrong rate. If it is a Ram 2500, order 2100FPE for the correct platform.

DS platform, diesel, 4WD, 6 inches, FOX 2.5 PE — the 2104FPE is the complete, correctly-specified front-end solution for the Ram 3500 diesel tow rig that needs consistent geometry and consistent damping at maximum DS lift height.

Common Questions

What is the difference between 2104FPE and 2104FS?
Both kits fit the 2013–2018 Ram 3500 4WD diesel and deliver 6 inches of front lift with the same BDS radius arms, diesel-tuned springs, and track bar correction bracket. The only difference is the shock — 2104FPE uses FOX 2.5 PE with external reservoir and advanced valving. 2104FS uses FOX 2.0 without external reservoir at a lower price point. For sustained towing and aggressive off-road use, the 2.5 PE is the correct specification. For daily and moderate use, FOX 2.0 covers the application at lower cost.

Why does this kit not fit the 2019 Ram 3500?
The 2019 and newer Ram 3500 is the DT platform — completely different front suspension architecture from the 2013–2018 DS platform. The radius arm geometry, spring rates, and correction brackets are not interchangeable between platforms. Order 1683FPE (with overload leaf) or 1682FPE (no overload leaf) for the DT platform.

What is the driveline inspection for and can I skip it?
At 6 inches of lift, driveshaft angles change significantly from factory. U-joints operating outside their designed angle range wear rapidly and can fail under heavy diesel towing load. The inspection confirms whether your driveshaft requires modification — on a diesel towing platform at 6-inch lift, this is not optional.

Does this kit lift the rear of the truck?
This kit addresses front lift via the radius arm upgrade. Rear lift components are not included. Confirm rear lift requirements with your installer before ordering if needed.

Is this a DIY install?
No. A 6-inch radius arm lift on a diesel platform requires a qualified suspension shop. Professional installation is required.

What warranty does this kit carry?
BDS suspension components carry the BDS No-Fine-Print Warranty. FOX 2.5 PE shocks carry a FOX 1-year limited warranty.

Verified Fitment