norsk

I am new to this site, and it seems very helpful. So, my question is, what is the difference between the 6spd and the heavy duty 6spd, for a 2005 2500. I am considering purchasing the truck new, but so far haven't gotten a clear answer from the dealer about the difference. I don't plan on doin gmuch towing, I just want a full size truck that will get (at least) decent mileage. Thanks!

STATELINE

for what it's worth, I just don't like the gearing of the G56, I test drove an 05 with it, & at 70mph with 3.73 gears it turned 2250 rpm, my 04 auto with 4.10's only turned 2150 bought the one with NV5600, it turns under 2100




for reference;
04 auto 4.10's 70mph=2150rpm
05 G56 3.73's 70mph=2250rpm
05 NV5600 3.73's 70mph=2075rpm

norsk

okay, forgive my lack of knowledge, but which one is the G56? I assume that is the heavyduty (?).

Muzzy

Here are the descriptions out of the 2005 Dodge Truck Driveline specs:

"NV5600HD Six-Speed Manual Transmission
A six-speed manual transmission is available only on Ram
2500/3500 when powered with the 5.9-liter Cummins®
600 Turbo Diesel engine.
The six-speed gearbox features close-ratio gearing, eliminating
the “gaps” between second, third and fourth gears found
in five-speed manual transmissions. This allows the driver
to match road speed and engine rpm more closely for
improved performance and fuel efficiency. The six speed’s
close-ratio gear also improves trailer-towing performance
on grades, as there is less speed and rpm drop when the
transmission is shifted to a lower gear.

G-56 Six Speed Manual Transmission
At the mid-year mark the DaimlerChrysler CVD G-56
manual transmission will replace the NV5600 on RAM
2500/3500 when powered with the 5.9-liter Cummins 600
Turbo Diesel engine. The G-56 six-speed manual
transmission will also replace the five-speed NV4500 on
Ram 2500/3500 when powered with the 5.7-liter
HEMI V8 engine.
Like the NV5600, the G-56 six-speed gearbox also features
close-ratio gearing, eliminating the “gaps” between
second, third and fourth gears found in five-speed manual
transmissions. This allows the driver to match road speed
and engine rpm more closely for improved performance
and fuel efficiency. The six-speed’s close-ratio gearing also
improves trailer-towing performance on grades, as there is
less speed and rpm drop when the transmission is shifted
to a higher gear. The lower ratio first “creeper” gear
improves launchability when fully loaded or when towing
trailers.
Ram 2500/3500 trucks equipped with the DaimlerChrysler
CVD G-56 manual transmission and powered with the 5.9-
liter Cummins 600 Turbo Diesel engine also include an allnew
dual mass flywheel which greatly improves NVH
performance. The Self Adjusting Clutch included with the dual
mass flywheel maintains lower clutch pedal efforts for the life
of the clutch."

I believe the "heavy duty" 6 speed is referring to the NV5600. The sales code for the NV5600 is "DEE". The G56 is listed as "DEG". I would check the sales codes with the dealer to confirm which one is the HD.

-Muzzy

GreyTD

I do believe both are HD, but the difference is the NV56 is cast iron body, which is in the 2005 and early models. The G56 is aluminum body and lighter in weight and is in 2005.5 and later models. someone will correct me if I'm wrong. Also NV56 is no longer available.

tycreek

HD in the option sheet at $400 is the old style ... NV5600 ... 6spd without "HD" is the G56 at no charge.

I had to search to find one to buy last week ... looks like they might be getting harder to find! Didn't want the DMF ... though yes it was smoother.

STATELINE

norsk,
NV5600- cast iron case, reverse is up & right next to 5th gear, sold as heavy duty, no longer available for order, but I found a few on lots a few weeks back when I bought mine.
G56- aluminum case, reverse is down & left next to second gear, was regular duty, now all that is available.

I prefer the NV5600, it's tried & true, just feel better with a cast iron case with this much torque, & has a higher 6th gear=lower highway rpm=better economy

if you are located in my area, I could point you toward a couple dealers that might still have some.

norsk

Thanks everyone. It sounds like I would prefer the 'old' NV56, especially if it has better (for fuel efficiency) ratios. As a follow-up question, does anyone know the ratios for each tranny?

4x4not

NV5600:

1st - 5.63
2nd - 3.38
3rd - 2.04
4th - 1.39
5th - 1.00
6th - 0.73

G56:

1st - 6.29
2nd - 3.48
3rd - 2.10
4th - 1.38
5th - 1.00
6th - 0.79

TorqueFreak

NV 5600: G56:
1- 5.63 1- 6.29
2- 3.38 2- 3.48
3- 2.04 3- 2.1
4- 1.39 4- 1.38
5- 1 5- 1
6- 0.73 6- 0.79

12PACK

Tycreek, I think you have an error in your sig.