2007 Jeep Wrangler Chief Engineer Jim Issner has responded to email questions:
6. "I didn't want to paraphrase this next question, it comes from one of our readers with the nickname, 'disturbed': "The number 1 question I have is WHY OH WHY DID YOU GUYS STICK A D35 UNDER THIS THING? "
This is THE most hated Jeep/Dana axle assembly ever produced and to continue to use it under the entirely new JK platform (even with upgrades) is mind-boggling. The D44 or AAM equivalent should have been used across the board for all JKs."
""The Dana 30 front axles have a high pinion design (TJ was a low pinion design) to provide greater gear strength, the housing is stiffer and stronger, and the pinion bearings are larger for improved durability.The Dana 35 rear axle also has a larger pinion and unitized wheel bearings. The prior design had an on-shaft bearing. The axle shafts have also increased in cross section for improved strength. Overall, the axles have been improved over its predecessor. In fact, we are considering different names for the axles since they are virtually all new""
A Jeep spokesman was also quoted as saying that the Dana44's were so much bigger that they considered renaming them Dana45's. I'll try to find that to post, too.