The ‘X’ means the casing is designed to mate with a transfer box. I mention this here : http://www.xoutpost.com/bmw-sav-foru...-teardown.html

Though it varies depending on the torque converter used, the generation 1 transmissions had (maximum input) torque capacities of :

6HP19 = 400Nm
6HP26 = 600Nm
6HP32 = 750Nm

(The early ‘basic’ 6HP26 came fitted with the W260 S converter with an input torque capacity of only 440Nm, to match the 5HP24, but the upgraded model used the W280 S converter, had more plates in the clutches and used a 4-planet carrier in the front epicyclic, which increased this to 600Nm)



The generation 2 models have maximum input torque capacities of:

6HP21 = 450Nm
6HP28 = 700Nm
6HP34 = 850Nm

again, this varies with the torque converter used)



Phil