I have had my 05 for 2 weeks now and love it. I don't understand something. I have been reading alot about the diff 6 speeds that are offered for this truck. The G56 and the 5600. Whitch one is the heavy duty one. Mine is the 5600 I guess, as it is cast iron and the shift pattern is with reverse on the right and up. I understand the the G56 is on the left and down. My window sticker and glove box option sticker say that it came with the Heavy duty 6 speed. So Is mine the HD or not?

 

From what I understand, the easy way to tell if not sure is to get on your hands and knees and look under the truck. If the tranny is cast iron (starting to get a rusty colour) then it is a NV5600, if it is nice and clean aluminum then it is a newer G56. As far as I know both are considered Heavy Duty but are just different makes of tranny's.

 

The G56 replaces the NV5600 as being the 6sp tranny available on the CTD.

 

hwp, you have a NV5600. If your Reverse is over by 6th, then it is a 5600. If Reverse is by 1st, then it is a G56

 

Sounds like you have the cast iron cased 5600. If so, it is probably the strongest tranny ever offered in a pickup. School is still out on the G56 but I'd be happy with what I had!

 

Check that again. I have an NV5600 and reverse is by 5th.

I was amazed when I first looked at an NV5600. If you didn't already know it was a stick, you would swear it was a slushbox based on the size of the thing. They are huge for a pickup transmission.