Did a search and couldn't come up with anything newer than a post from 2008.

My 07 Duramax/Allison is on its second set of transmission cooler lines and they're leaking again at the crimp. The truck is out of warranty and the dealership won't warrant the lines they replaced. You'd think GM could make a tranny cooler line that'll go longer than 30k miles before leaking, and if not, at least back up the repair. Didn't know these were consumable parts.

Anyone else have this problem? Anyone have success with custom made lines? I don't want to go through this in perpetuity.