BDS 5.5-Inch Radius Arm Lift Kit | FOX 2.5 Performance Elite | Ram 3500 4WD Gas 2013–2018 | SKU: 2105FPE

The BDS 2105FPE is a 5.5-inch radius arm front lift kit with FOX 2.5 Performance Elite external reservoir shocks for the 2013–2018 Ram 3500 4WD gas — the DS-generation platform. Heavy-duty BDS radius arms replace the factory arms, correcting caster at lift height and reducing bushing bind. Gas-tuned front coil springs deliver 5.5 inches of lift at the correct spring rate for the Ram 3500 gas platform. FOX 2.5 PE external reservoir shocks deliver advanced valving and heat-managed damping for sustained off-road and towing performance at lifted height.

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 1686FPE (no overload leaf) or 1687FPE (with overload leaf) for the DT platform. The 2012 and earlier Ram 3500 is not compatible.

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

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

This is a radius arm upgrade — not a leaf spring system. For the DS Ram 3500 gas platform with FOX 2.0 shocks and a leaf spring rear system at lower cost, see 1619FS.

Component Specifications

What Is and Is NOT Included

Critical Compatibility

Three fitment confirmations required before ordering.

Want FOX 2.0 with leaf springs on this same platform? Order 1619FS.
Not sure which Ram 3500 generation you have? Text (469) 407-7538 before ordering.

2105FPE vs. 1619FS — Which Kit Do You Need?

DS vs. DT Generation Reference — Ram 3500 Gas

Tire Clearance

At 5.5 inches of front lift on the 2013–2018 Ram 3500 gas platform, typical fitment runs 35–38-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 5.5-inch radius arm lift 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 5.5-inch lift on the Ram 3500 platform, correct alignment is critical for tire wear and steering geometry under towing load.

Driveline inspection is required after installation. Inspect driveshaft angles and U-joint operating angles after installation. Confirm angles are within acceptable operating range before towing.

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 3500-class 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, generation, and drivetrain before ordering.

The Obsidian Take

The BDS 2105FPE is the correct kit for the 2013–2018 Ram 3500 4WD gas owner who wants 5.5 inches of front lift with maximum shock performance — no leaf spring rear system, no FOX 2.0 compromise, just a radius arm upgrade and FOX 2.5 PE external reservoir damping built for the sustained towing and off-road demands of the DS-generation 3500 gas platform.

The comparison with 1619FS is the honest one. 1619FS delivers 5.5 inches of front lift and matched rear lift via replacement leaf springs with FOX 2.0 damping — a complete front-to-rear package at a lower price point. 2105FPE delivers the front-end radius arm upgrade with FOX 2.5 PE external reservoir performance and no rear lift components included — maximum front damping performance at higher cost, rear lift sourced separately if needed. If your build prioritizes maximum shock performance and you are sourcing rear lift independently, 2105FPE is the correct specification. If you want a complete front-to-rear lift package at lower cost on the same platform, 1619FS is the correct choice.

If your Ram 3500 is a 2019 or newer DT platform, the DS geometry does not apply — order 1686FPE or 1687FPE based on your overload leaf configuration. If it is diesel, gas-tuned springs are not the correct rate. If it is a Ram 2500 or Ram 1500, this kit does not apply.

DS platform, gas, 4WD, 5.5 inches, FOX 2.5 PE — the 2105FPE is the complete, correctly-tuned front-end solution for the DS Ram 3500 gas owner who wants maximum damping performance at this lift height.

Common Questions

What is the difference between 2105FPE and 1619FS?
Both kits fit the 2013–2018 Ram 3500 4WD gas and deliver 5.5 inches of front lift. 2105FPE uses FOX 2.5 PE external reservoir shocks with a radius arm upgrade — no rear lift components included. 1619FS uses FOX 2.0 shocks with a leaf spring rear system that includes matched rear lift via replacement leaf springs. Choose 2105FPE for maximum front damping performance. Choose 1619FS for a complete front-to-rear lift package 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 1686FPE (no overload leaf) or 1687FPE (with overload leaf) for the DT platform.

Why can't I use diesel springs on my gas Ram 3500?
The diesel engine is significantly heavier than the gas engine. Front coil springs are tuned for a specific front axle weight — diesel-tuned springs under a gas engine deliver excessive spring rate and harsh ride. Gas springs under a diesel engine sag and compromise geometry under load. The correct spring tune for your engine is not interchangeable.

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. If matched rear lift is part of your build, see 1619FS for a complete front-to-rear system, or confirm rear lift requirements with your installer before ordering.

Is this a DIY install?
No. A 5.5-inch radius arm lift 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