TRNW-2: 722.6 How to ID Internal gear ratio

[art landeck]

The NAG1 transmission, also known as the Mercedes-Benz 722.6 or W5A580, 
is a 5-speed automatic transmission that was widely used across various 
Mercedes-Benz, Chrysler, Dodge, Jeep, and other vehicles. While the NAG1 
is a single transmission design in terms of its core architecture, it 
does not have multiple "versions" defined strictly by different gear 
ratios. Instead, the gear ratios for the NAG1 are consistent across its 
applications, with variations in its implementation based on torque 
capacity, clutch pack configurations, and electronic control adaptations 
rather than gear ratio differences.

The standard gear ratios for the NAG1 (722.6) are:

  * 1st Gear: 3.59:1
  * 2nd Gear: 2.19:1
  * 3rd Gear: 1.41:1
  * 4th Gear: 1.00:1
  * 5th Gear: 0.83:1
  * Reverse: 3.16:1 (sometimes listed as 3.17:1 due to rounding)

These ratios are achieved through three planetary gear sets and are 
fixed across the NAG1 family. However, the transmission comes in 
different models or "versions" based on torque capacity and internal 
components, not gear ratios. These variations are designated by codes 
like W5A330, W5A380, W5A580, and W5A900, where the number (e.g., 580) 
indicates the maximum input torque capacity in Newton-meters (580 Nm, or 
approximately 428 lb-ft). The differences between these versions lie in 
the number of clutch plates, planetary gear pinion counts (e.g., 
three-pinion vs. four-pinion carriers), and other internal 
reinforcements to handle varying power levels, not in the gear ratios 
themselves.

For example:

  * *W5A330*: Designed for lower-torque applications (up to 330 Nm),
    often used in smaller engines.
  * *W5A580*: The most common variant, handling up to 580 Nm, used in V6
    and V8 applications like the Chrysler 300 and Dodge Charger.
  * *W5A900*: A high-torque version (up to 900 Nm), used in V12 Mercedes
    models and some AMG vehicles.

While these versions adapt the transmission to different vehicles and 
power outputs, the gear ratios remain the same. The variations are 
mechanical and electronic, tailored to specific vehicle dynamics, final 
drive ratios, and performance needs, rather than changes to the 
transmission's gearset ratios.

In summary, there is effectively *one set of gear ratios* for the NAG1 
(722.6) transmission across all its versions. The different "versions" 
(e.g., W5A330, W5A580) are not distinguished by gear ratios but by 
torque capacity and internal component differences. Thus, based on gear 
ratios alone, there is only *one version* of the NAG1 transmission. If 
you're looking for distinctions based on other factors like torque 
ratings or applications, there are several, but the gear ratios remain 
consistent.



tucker tuckertrans.com via trnw2 wrote on 4/4/2025 9:19 AM:
> Group,
>
> Is there a chart anywhere that you can ID the different gear ratios of 
> the Nag1 transmission?   I looked on ATRA and ATSG, but I didn't come 
> up with anything.  I could have missed it.  We need this to ID the 
> installed unit when someone has swapped out a salvage unit.
>
> Dan Tucker
>
>
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