I am new to the chevy diesels. I am looking for a 2500 6.6. I have had diesels and they have all been 6 speeds. I am just wondering if in a chevy if it is better to get the 6 speed or the allison automatic. If i get the automatic will i be dissappointed.Also is there anything to worry about with the auto? Manual? Thanks in advance

 

I've always had great experiences with all of Chevy's automatic transmissions. Especially the Allison, i've never noticed any power difference between the automatic and the 6 speed and i've drivin both. Good luck

 

depending on what year your looking the Auto will be your only choice, GM dont make a manual anymore, and have not for well few years, the auto you will find is awsome, as opposed to the older Dodge, they only had a 4 speed Auto so the manual 6 speed made more sense, but hte Allison is a auto 5 speed, and shifts very nice, and you will not notice ANY lag in power

ALL new trucks are equipped with a 6 speed Auto with tap shift I beleive now, at least GMs are and Doge I beleive as well, not sure on the tap shift for Dodge and Ford....so the manual is no more from GM....but with the tap shift you dont need it, same thing just no clutch to screw with.

As fr worries, the Allison is one tranny you wont have to worry about.