New G56 manual for 2005

[PaulG1]

Does anyone know the status of the "new" manual trans. Or better yet has anyone test driven one? Any word on the durability compared to the NV5600?



Thanks,



Paul

 

[Vaughn MacKenzie]

Not sure Paul, there is a thread about this in the 3rd Gen Engine forum. Vaughn

 

[lil red cummins]

do a search on G56. there are a few comments and links on it.



my biggest concern about it is that it has a higher ratio 6th gear.



in MHO my 04 with the 3. 73 is already turning too many RPM's at 70 MPH. i wish they would bring back the 3. 55 or even lower.



i can always downshift if on a grade. anyone else feel this way?



jim

 

[rashwor]

The cummins is just getting into it's "happy zone" at 1800 rpm. You are turning about 2100 rpm at 70 mph with stock tires and a 3. 73, NV5600. This setup is why these trucks tow loaded so well at 70mph. You put a higher top gear, you reduce the rpm much below 2100 at 70, and you won't tow much in 6th gear.



If you want to run empty or dragrace, taller fewer gears are what you want.



JMO.

 

[DPelletier]

You guys are confusing higher numeric ratios and higher gear ratios. Personnally, I prefer to discuss ratios in terms of gear ratios, ie. 4. 10's are lower than 3. 73's.



Anyway, I'm perfectly happy with my 3. 73's and the NV-5600, although if I had to go one way or the other, I'd change the OD to be lower (more RPM) to allow me to stay in 6th more often up mountain passes at 18,000 GCVW. My 2001. 5 3. 55 SO auto (with the higher OD than the standard) couldn't tow anything in OD between the low power output (stock) and the overly high OD gearing.



As far as the G56 goes, I think it is too early to tell how it compares from a reliability standpoint vs. the NV-5600. One thing for sure, the G56 has big shoes to fill. I am glad to hear it isn't a Getrag, but I do prefer the NV-5600's iron case. Only time will tell. IMO you need to wait at least a couple of years to answer that question, unless they start crapping out way early.



Cheers,

Dave

 

[RustyJC]

Anyway, I'm perfectly happy with my 3. 73's and the NV-5600, although if I had to go one way or the other, I'd change the OD to be lower (more RPM) to allow me to stay in 6th more often up mountain passes at 18,000 GCVW.

Dave,



With the 4. 10's, all I want is a 7th gear for running empty! Hey, there's a hole they aren't using over there in the Reverse gate!! Oo.



Rusty

 

[klenger]

I'm interested to hear how the G56 shifts, etc. from a drivability standpoint. To discuss it's dependability at this point is useless, unless it has a history from some other appilcation.



Rusty: What are you doing hanging around here with us 3rd gen'ers? Window shopping?

 

[RustyJC]

Ken,



Nope. At least until recently, we did share a NV-5600 transmission.



Rusty