i owned an 05 cummins with the auto...i liked the truck, i never really pull heavy, 5k max... ex wife took kit in the divorce...i found a 05 low miles with the 6 sp. manual. my buddy has an 04 6spd, and it seems fine. i hear the manual trans if bulletproof, any feedback welcome. thanks in advance

 

05's had two different six speeds. Early versions had the NV5600. Late versions have the Mercedes built G56. Both transmissions have good reputations, but the G56 has a lower OD gear, which reduces mileage. G56's also come with a ridiculously expensive two piece flywheel. You can tell the difference between the two transmissions by looking at the shift pattern. G56's have reverse down and left. I believe NV5600's have it right and up. Someone will correct me, if I'm wrong.

G56's shift very well. Some say NV5600's aren't as smooth. I've driven a NV5600 only a short distance, but it didn't seem too bad to me. I do like how my G56 shifts.

NV5600 parts are said to be hard to come by. The transmission is currently out of production.

 

G-56 is geared differently and you'll be buzzin at highway cruising speeds (that's 75-80 out here). MPG takes a hit with the G trans.