Comments regarding an increase in Transmission Gear Rattle after converting from a Dual Mass Flywheel to a Solid Flywheel

Some owners have reported an increase in transmission gear rattle after installing a Solid Flywheel Conversion Clutch Kit in their vehicle when the truck is in neutral and idling. This is known as Gear Roll Over noise. It is a rapid tapping, clicking, or rattling sound. Some owners say it sounds like marbles in a jar. It occurs in all transmissions to varying degrees, no matter what type of gears are used. The rattle and vibration is caused by gears moving back and forth relative to each other. When the gear teeth bounce off of each other, they make a rattling noise. This gear rattle primarily occurs when the vehicle is at idle, in neutral, with the clutch pedal up.

The gear roll over noise heard will not affect transmission or drivetrain wear per OE clutch manufacturers, all of whom sell a stock version of these kits. If you would like to reduce the level of noise, the following fixes have been offered up under several of the Dodge Cummins Diesel oriented blogs. Phoenix Friction Products offers these fixes merely as references to what is being discussed amongst vehicle owners. We do not sell these items.

• For a Cummins 5.9L - Add a Fluidampr Harmonic Balancer – it provides 80% better vibration dampening with Silicone fluid.  The 6.7L comes equipped from the factory this way.
•  Add an additional two quarts (total of 7 quarts) of Mobil ATF+4 and remove the sensor (may void manufacturer’s warranty) or
•  Add 24 ounces of Lucas Transmission Fix or
• Replace ATF with 7 Quarts of either of the following:
  • Mobil Delvac Synthetic Transmission Fluid 50 or
  • Schaeffer 239S SAE 50 Gear Oil or
  • Amsoil MTG Manual Transmission & Transaxle Gear Lube 75W-90 or
  • High Performance Gorilla Juice Manual Transmission Fluid

The fluid can be poured into the transmission by removing the stickshift from the top of the transmission. Leave the fill plug on the side of the transmission in place. Make sure that the transmission is filled to the correct level. Less fluid will cause more noise.

These suggestions all assume that prior to the solid flywheel conversion, the transmission was inspected by a qualified technician for excessive end-play or movement of the input shaft caused by worn bearings or the housing. Excessive movement is a common complaint from Ram owners and their mechanics.