You are correct, you cannot get 4.10's with a six-speed anymore. The new G-56 trans has a .79 6th gear, whereas the old NV5600 has a .73 6th gear. Also first thru third gears are lower on the new trans..fourth and fifth are about the same. Much better trans for pulling heavy as I do. IMHO

 

The 6 speeds and for that matter the five speesds have NEVER been a overdrive trans in the Dodge diesel trucks.Only automatics.

 

Not quite sure what you are saying here but the all the manuals behind the Cummins have been an overdrive transmission, 5th is overdriven in the NV4500 and G360, 6th is overdriven in the NV5600 and G56.

If you are talking about the G56, a standard build does not include the 4.10's due to the lower 6th gear ratio. You can special order the 4.10's but it is not really needed.

Saying "new 6 speeds" sounds like you mean the new auto's which have double overdrive and are readily avaialble with the 4.10's.

 

No 6, Maybe you could have the dealer install 4.10's with the 6-speed manual, but you cannot order it that way.

 

The 5 and 6 speeds have never been adverstised as overdrive trannys.Only the autos.The gear splits certainly do not feel like overdrives.For the most part except the 5 speeds(3rd to 4th)the gear splits are evenly split.In a true OD unit its a large jump into the high(overdrive)gear. Chrysler has made true od manual trans in the past.Large jump into OD.

 

I thought, by definition, that an overdrive gear is on with a ratio higher than 1.00. Well the NV5600 and the G-56 both have a 1.00 fifth gear and .73 and .79 sixth gears. That would make their 6th gear an overdrive??

 

Thats what i was thinking too

 

I believe that to be correct as well......

 

Saying "new 6 speeds" sounds like you mean the new auto's which have double overdrive and are readily avaialble with the 4.10's.[/QUOTE]

Sorry... I meant the G56 trans when I said "new 6-speed"

Another thing, my truck has stock tires and the top speed is about 94MPH. And at this speed I'm just in the redline. So I would guess a 3.73 truck might go at few MPH faster...Another easy way of determining your gear ratio--sort of.

 

At 70mph im in-between 2k and 2100 rpm with my 3.73's

 

I have 4.10's too and yes 70mph is about 2100-2200 with the automatic, and I dont like it. If you don't know just look at your options sticker. I am thinking about swapping them out for 3.73, or even 3.42. Not till spring though.

 

Where else can you look to find your gear ratio? It doesn't say on the sticker, but that doesn't mean anything. I went to order my topper and the paint code on the door doesn't match the paint on the truck.

 

I dont get it why did they make the auto and the 6 spd so close with the gearings?? I would have thought that the 6spd would have had a lower rpms at the same speed as an auto??

*EDIT* Would that be right for me with 3.73 gears?? 70mph with 2-2100rpms?

 

I have the auto and 3.73. Works well even towing 7-8k. Good mpg, staying with stock tires. Big tires eat MPG, power and brakes. If I had a gear problem I would look at a Gear Vendors, under-over drive unit that would give me all the gears anyone would ever want.

 

You have the NV5600 manual trans. and Hauliday has the G-56 manual trans. thus the difference