722.6 W5A580 Torque Rating Explanation

722.6 W5A580 Torque Rating Explanation

A lot of misinformation out there about transmission torque ratings.  A common response is there is no way an AMG E55-CLS55-S55-Sl55-CL55 has that W5A580 transmission in it, as these cars put out more torque than the factory rating. 

Regardless of what the factory specs say (580nm-428 ft-lbs) it’s commonly known that the Nag1 (722.6) real-life threshold is close to 600 ft. lbs as long as torque reduction is proportional to torque input during shifts before you need to beef up the tranny by adding torque capacity to clutch packs by adding extra frictions and valve body for higher pressure.

These transmissions use torque management to control torque inputs and during shifts, remove that and it is very hard on the transmission and most likely fry clutches during high torque shifts.

Factory specs have a large safety margin built in to insure it won’t fail during “Normal operating conditions”. Of course, failures can happen at any time but below 550-600 ft. lbs. is considered a safe zone.

Now V12 transmission 722.649-722.648 (800nm-900nm) has a beefier planetary gearset but a longer case and uses the same amount of clutches the 722.6 v8 model uses from many teardowns and inspections showed the same clutch counts and utilizes more torque management control in firmware. Will be either double-sided or single-sided clutches depending on the years. I recommend using single-sided clutches or aftermarket alto red frictions with koleen steels. There are so many different ways to beef up these transmissions. Stock W5A580 is pretty stout as it is.


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