Go to a GM diesel forum....a great many of those guys have modified engines, some extremely modified. A great many of them race. Lots of them tow heavy. And most run oversize tires. Ask now many differentials have broken.
Wow. That took all of 30 seconds to find.
Duramax forum. 2008 black LMM CC/SB 4x4
"So i was going to change the fluid in my Duramax with the G80 locker and found a piece broken inside. My truck is pretty much stock."
Duramax diesels forum. 07 2500HD CC LBZ
"G80 sucks. This has to be the most disappointing part of this truck."
"IMHO the g80 sucks i have broke 3 of them and it cost alot of money each time."
diesel place forum. "DMAX 2500HD. My truck is sitting at the dealership right now getting the G80 differential torn down due to excessive metal shavings after only 5000 miles."
06 Chevy CC/SB 4x4
"My g80 just snapped some ring (3 places) on the drivers side of the diff."
