And The Aftermarket Parts That Address Them
For more than two decades, the Allison name has been synonymous with the Duramax, the common-rail, aluminum headed V-8 that put GM back at the forefront of the diesel pickup segment. The industrial-strength Allison 1000, with its 1.26-inch diameter input shaft, massive 1.75-inch output shaft, 12.2-inch diameter torque converter, and 330-pound heft was far superior to the 4R100 and 47RE available in the Ford and Dodge competition when it debuted in 2001. Since then, the Allison has gone from handling an input torque rating of 520 lb-ft to a mind-boggling 910 lb-ft at present, and chances are the current 10-speed rendition will be asked to grapple with even more in the future.
Of course, it’s also no big secret that the commercial-grade Allison has its fair share of shortcomings, namely when it’s tasked with harnessing large increases in horsepower and torque. Clutch pack failures and slipping factory torque converters have perpetually been a weak link when the Duramax ahead of it has been turned up. And at higher horsepower levels many have found out the hard way that the factory C2 hub and P2 carrier can fail catastrophically. We’ll cover each of those failure points plus a few more this time, along with their appropriate aftermarket solution(s). Whether you’re looking to preserve the life of your stock Allison or build it right the first time you pull it, you’ve come to the right place.
Bonus Round: Transfer Case Failure