Fluidampr Dodge/Chrysler/Jeep 5.7L/6.1L/6.4L Gen III HEMI Steel Internally Balanced Damper

Eliminate Gen III HEMI Torsional Vibration With a Viscous Steel Damper That Adapts Automatically

The Fluidampr 720361 is a steel internally balanced performance damper engineered specifically for naturally aspirated Dodge, Chrysler, and Jeep vehicles equipped with the Gen III HEMI 5.7L, 6.1L, or 6.4L V8 engine. Unlike OEM rubber-bonded dampers that degrade over time and can only target a narrow resonance frequency, the FDR720361 uses a precision viscous fluid mechanism that automatically adapts to any engine modification and self-tunes continuously across the entire RPM range. The result is consistent, effective torsional damping whether the engine is stock, mildly modified, or built for high-output street use.

Key Features

• Fluidampr 720361 uses viscous fluid technology that self-tunes in real time to suppress torsional vibration across the entire RPM range on 5.7L, 6.1L, and 6.4L Gen III HEMI engines
• Precision machined steel construction is internally balanced to match the Gen III HEMI factory balance specification, maintaining proper engine balance without external counterweights
• Automatically adapts to any engine modification including cam changes, stroker kits, forced induction, and increased compression, requiring no re-tuning of the damper itself
• SFI 18.1 certified for safety-critical performance applications including sanctioned drag racing and road racing events with technical requirements
• Reduces wear on main bearings and timing components by controlling crankshaft flex and torsional stress that originates from combustion impulses
• No rebuild, retuning, or maintenance required over the service life of the damper
• Made in the USA by Fluidampr (Vibratech TVD), the originator of viscous performance damper technology for the automotive aftermarket
• FDR720361 is a direct-fit replacement damper for the Gen III HEMI 5.7L, 6.1L, and 6.4L — no adapter or modification required for installation on compatible vehicles

Vehicle Fitment

Specifications

What's Included

• 1x Fluidampr 720361 steel viscous performance damper
• Fluidampr installation instructions

About Fluidampr

Fluidampr is manufactured by Vibratech TVD in Springville, New York. Vibratech has been engineering viscous torsional dampers for industrial and performance applications for decades, and Fluidampr represents their automotive performance division. Every Fluidampr damper is precision machined, computer balanced, and manufactured to ISO 9001 quality standards entirely in the United States. The 720361 for the Gen III HEMI 5.7L, 6.1L, and 6.4L reflects the same engineering that has made Fluidampr the preferred viscous damper brand across professional motorsport and demanding street applications alike.

FAQ

The factory OEM harmonic balancer on Gen III HEMI engines uses a rubber-bonded design that targets a fixed resonance frequency. Over time the rubber bond degrades from heat cycles, ozone exposure, and mechanical stress, reducing the balancer's effectiveness and ultimately risking separation. The Fluidampr 720361 replaces the rubber bonding with a sealed, precision viscous fluid mechanism. The viscous fluid automatically adapts to any change in the engine's resonance signature, including changes caused by modifications. It does not degrade in the same way as a rubber damper, and it does not require replacement on a maintenance schedule.

No. The Fluidampr 720361 is designed exclusively for naturally aspirated Gen III HEMI engines: the 5.7L, 6.1L, and 6.4L. The supercharged 6.2L SRT Hellcat, Redeye, and Demon engines require a different Fluidampr damper. For the 2015 to 2021 Hellcat Charger and Challenger 6.2L supercharged engine, Fluidampr offers part number 840302 (standard) and 910302 (11% overdrive). If you are unsure which engine you have, check the engine code decal in the engine bay or confirm via the vehicle VIN decode.

Yes. The Fluidampr 720361 is SFI 18.1 certified. SFI 18.1 certification is required by many sanctioned motorsport organizations, including NHRA and NMCA, for vehicles running at certain elapsed time thresholds. If you are building a car for a sanctioned event with a tech inspection, verify which damper SFI rating applies to your elapsed time class before purchasing.

No. The FDR720361 is designed to reuse the factory OEM crankshaft bolt and related mounting hardware from the Gen III HEMI. No additional mounting hardware is included or required. However, Fluidampr recommends using a torque wrench and torquing the crankshaft bolt to the factory specification during installation. On Gen III HEMI engines, the crank bolt is a torque-to-yield fastener and should be replaced with a new OEM or aftermarket fastener if the bolt has been previously torqued and removed.

Yes. One of the primary advantages of viscous damper technology is its ability to automatically adapt to any change in the engine's torsional resonance profile. Modifications such as camshaft upgrades, stroker assemblies, increased compression, nitrous oxide systems, or porting and cylinder head work all alter the engine's torsional vibration characteristics. A traditional rubber damper tuned for the stock engine will become progressively less effective as these modifications move the resonance frequency away from its fixed tuning point. The Fluidampr 720361 continuously responds to whatever resonance frequency the engine generates at any given moment, making it effective regardless of how significantly the engine has been modified.

Internal balance means the Gen III HEMI engine's rotating assembly is balanced using counterweights machined into the crankshaft itself. The 720361 is manufactured to match this internal balance specification and does not include external bob weights on the damper face. This is in contrast to externally balanced engines, where offset weights on the damper and flywheel are used to complete the balance of the rotating assembly. Using an internally balanced damper like the 720361 on an internally balanced Gen III HEMI ensures the rotating assembly balance is not disrupted.

The 720361 is a damper only and does not include a separate accessory drive pulley unless stated otherwise. On most Gen III HEMI applications, the OEM serpentine belt drive pulley is integrated into or mounted directly to the factory damper. When switching to the Fluidampr 720361, confirm that the pulley from the OEM damper is compatible for transfer or that a compatible aftermarket pulley is available for your specific application. Contact Fluidampr or your installer for application-specific guidance if you are unsure.

Fluidampr offers a 1-year limited warranty on the 720361 covering defects in material and workmanship for the original retail purchaser, with proof of purchase required. The warranty does not cover failure due to improper installation, misuse, modification, race or competition use, or normal wear. To initiate a warranty claim, contact your point of purchase first, as all warranty claims must be initiated through the selling dealer or retailer. A return authorization number is required before returning product to Fluidampr.

The FDR720361 is designed to retain the stock accessories drive configuration for naturally aspirated Gen III HEMI applications. The outside diameter and belt groove layout are engineered to maintain the factory serpentine belt routing and tensioner geometry. If you have installed an aftermarket underdrive pulley system or a modified accessory drive, confirm that the 720361's OD and pulley configuration are compatible with your setup before installing.

Installation Instructions

1. Disconnect the negative battery terminal before beginning installation.
2. Remove the serpentine belt by relieving tension at the belt tensioner using an appropriate breaker bar or tensioner tool.
3. Remove the crankshaft bolt using an impact wrench or appropriate holding tool to prevent crank rotation during removal. Note that the Gen III HEMI crank bolt is a torque-to-yield fastener and should be replaced rather than reused if it has been previously removed and torqued.
4. Remove the OEM harmonic balancer from the crankshaft snout using a two- or three-jaw puller. Do not use a hammer or impact tools on the balancer face.
5. Inspect the crankshaft snout for wear, corrosion, or damage. Clean and dry the mating surfaces before installation.
6. Verify the keyway alignment and install the Fluidampr 720361 onto the crankshaft snout. The damper should slide on by hand with proper alignment. Do not hammer the damper onto the snout.
7. Install a new crankshaft bolt (or the factory bolt if it has not been previously torqued) and torque to the manufacturer-specified value in stages. Refer to the factory service manual for the correct torque-to-yield procedure for the Gen III HEMI crank bolt.
8. Reinstall the serpentine belt following the factory belt routing diagram. Confirm the belt is properly seated in all pulley grooves.
9. Reconnect the negative battery terminal and start the engine. Confirm no unusual vibration, noise, or belt tracking issues are present before returning the vehicle to service.

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