i have a 2002 duramax /allison purchased new in 2002
no problems other than the front wheel bearing hub assembly.
i have had 8 trucks 8 lug axles since my first new car a c20 suburban big block 402 .
i was buying a new pickup every 5 years until i bought my duramax.
this thing is so good i have not found a reason to replace it .
i find it quieter than my previous big block gassers on the highway , especially when towing my boat .
the 5 speed allison is the best tranny for towing i have used . great 1st gear and excellent compression braking .
i used to drive very fast over these Oregon 2 lane highways , even when towing .
i stopped when diesel became $ 4 a gallon .
for that reason i find 520 foot pounds torque more than adequate .
i need to slow down so i have not switched to the newer 765 foot pound version.
a good upgrade for me was to go to the LT 265/75R16 LRE Michelin highway tires on 8 inch wide wheels. the stock 245/75r16e on 6.5 inch wheels do not handle near as well .
the low allison first gear makes the switch from 245 to 265 a reaonable compromise .