Anybody heard any recent news on AAM 3.42 gear set lately. My six speed has 3.73 and is running a high RPM at highway speeds. If AAM comes out with a 3.42 or 3.55 would these gears drop RPMS considerably or would you barely notice?

 

Divide 3.73 into 3.42 then multiply that into your current RPMs at speed to see your new RPM.

Joe

 

Have you tried calling AAM?

 

Yeah i did and they put me on hold for ten minutes and i hung up, that was about four months ago.

 

Here is teh release from the website...

American Axle & Manufacturing Introduces New Exclusive 3.42 PowerDense® Gear Set Designed to Improve Fuel Economy
AAPEX Show Booth #1458
PRNewswire-FirstCall
DETROIT
(:AXL)

DETROIT, Oct. 16 /PRNewswire-FirstCall/ -- American Axle & Manufacturing (AAM), which is traded as AXL on the NYSE, today announced a new exclusive aftermarket 3.42 PowerDense® gear set for 2003 to 2007 Dodge Ram Heavy Duty 2500/3500 turbo diesel pickups. The gear set and its technology will be showcased at the Automotive Aftermarket Products Expo (AAPEX), October 31 through November 2.

AAM Aftermarket now offers Dodge Ram diesel pickup owners the 3.42 ratio gear set as an alternative to the numerically higher ratio gear sets that are currently available. The lower ratio set reduces engine rpm, which helps improve fuel economy under normal driving conditions which exclude hauling, climbing grades, or pulling a trailer.

The 3.42 ring and pinion is designed to fit inside the original equipment AAM 9.25-inch front and 11.5-inch rear axles without modifications to the transmission or the truck's on-board computer. In pre-2007 pickups the front axle requires a new redesigned differential case along with new side and differential pinion gears. All 2007 models have the advantage of coming with a factory installed redesigned differential case, side and pinion gears making the installation process easier.

AAM PowerDense® Ring and Pinion Gear Sets

AAM utilizes state-of-the-art face hobbing to generate the gear tooth form in a two-cut process. This represents AAM's latest effort to enhance NVH, durability, quality and reliability of its ring-and-pinion gear sets. The key advantage of a two-cut gear set occurs when the components are being hobbed or generated. Hobbing creates more surface area and equal tooth depth. This produces lower alternating bending stress levels while creating a more even distribution of loading across all of the teeth. The results are reduced levels of NVH and increased durability.

Another key advantage of the two-cut process is the use of continuous indexing. In the manufacturing process the gear teeth are generated simultaneously with uniform tooth spacing and no imperfections.

Additionally, the two-cut manufacturing process permits tighter backlash specifications between the gear and the pinion. Backlash is defined as the amount of free play between two gears in their operating positions. The results are reduced heat, NVH, driveline clunk and increased gear set durability.

Finally, two-cut manufacturing is an environmentally friendly process. Since the components are dry cut, the presence of a coolant medium at the point of engagement of a tool and a component is eliminated. Without coolant, no mists or smoke are produced.

Tough Stuff

AAM PowerDense® gear sets are made from high quality Society of Automotive Engineering (SAE) steel purchased only from approved AAM and OEM steel suppliers. Special high core hardenability steel is utilized to enhance the design and manufacturing process of the gear sets.

Made Even Tougher

The specified steel also lends itself to precision shot peening which extends the life of AAM PowerDense® gear sets. In this process spherical shot is targeted at the root of the gear teeth and bombards the surface, resulting in compressive stresses to combat fatigue loading. The compressive stress increases AAM ring-and-pinion durability and reliability.

AAM parts are also forged, lapped and heat treated to meet OE manufacturers' stringent standards. Coordinate Measuring Machines (CMM) are then used to inspect the parts for accuracy.

AAM - Tough to Beat

AAM engineering teams have advanced the design and manufacturing processes of driveline systems, chassis systems and metal formed products since 1994. AAM designs, tests and validates its ring and pinion sets to vehicle manufacturers' exact specifications. AAM's on-going programs in NVH, thermal management, vehicle-system efficiency, dynamics and vehicle handling and other disciplines assure customers that the parts they are getting incorporate the latest product, process and systems technology.

For more information on AAM gear sets and other products and services, visit the Internet at http://www.aam.com/ or dial 1-800-299-AXLE.

 

Or you could just put on bigger tires!

 

I imagine if you make the change you will see rpm drop by about 200 rpm across the board. Probably save you 3/4 mpg if you drive smoothly.

 

My truck has the New G-56 6 speed that has a higher 6th gear. it runs about 200 RPM's lower than my 06 G-56 did...

 

I have taller tires and am still considering it

 

If you have a 2wd Dually it is kind of hard to put on bigger tires and would be more expensive than a gear swap. Just sayin.