FIRST DRIVE - G56 manual transmission

[Tomeygun]

TomeyGun, do you have any info on gear ratios for the new trans?



Thanks,

Jim

Page 14 of this file:

http://www.newdodgeorderform.com/My_Homepage_Files/Download/Truck_Drivelines2005%20(1).pdf

 

[RJOL]

Thanks for the info, Tomeygun... Lots of good stuff at this site.



Just a couple of questions/comments...



First: On page 13, it states "The lower ratio first "creeper" gear improves launchability when fully loaded or when towing. " I guess this means that Dodge is formally suggesting that you skip "L" or "1st" when not loaded.



Second: On page 14 it gives the specs on the new clutch. It appears to be smaller in both outside and inside diameter, but usable thickness is over twice as much as the 4. 5 gen clutch, and its total area is bigger by 25. 8 sq inches. Someone who knows more about clutches will have to chime in, but it appears to be a bigger clutch in "total area (sq in). "



Tomeygun: What is your impression about starting out in 2nd gear, and also the clutch pressure. On page 13 it suggest that the clutch pedal effort is lower. Also... What lubricant does the owners manual specify for this new transmission?...

 

[SRadke]

On page 14 it gives the specs on the new clutch. It appears to be smaller in both outside and inside diameter, but usable thickness is over twice as much as the 4. 5 gen clutch, and its total area is bigger by 25. 8 sq inches. Someone who knows more about clutches will have to chime in, but it appears to be a bigger clutch in "total area (sq in).

More square inches provides smoother engagement and better wear characteristics. However few things do as much for holding power as diamter and clamping pressure. We know they've decreased diameter and the new dual mass flywheels don't lend themselves toward high clamp loads. We shall see... ... .



-Scott

 

[bpenrod]

Looks like sixth is not as tall as the "old" six speed. Does it run a few rpm's higher at cruising speed??

 

[Tomeygun]

Tomeygun: What is your impression about starting out in 2nd gear, and also the clutch pressure. On page 13 it suggest that the clutch pedal effort is lower. Also... What lubricant does the owners manual specify for this new transmission?...

Heck, It started in 3rd gear with NO EFFORT at all



So 2nd gear starts were super easy



The engagement of the clutch was very smooth, almost perfect

 

[DBond]

Looks like sixth is not as tall as the "old" six speed. Does it run a few rpm's higher at cruising speed??

At 65 mph . 73 vs . 79 OD ratio will give you about 2100 vs 1940 rpm

At 75 mph 2420 vs 2240 rpm

(Stock tires, 3. 73 rear)

 

[DBond]

Great info Tom! Glad you're on our team Also, an aluminum case... ... interesting



-Scott

With that aluminum housing how much weight has taken off compared to the NV5600?



That should go right to increased payload right?

 

[bpenrod]

My current truck seem to get worse mileage above 2000 rpm, looks like the sweet spot there would be between 65 and 70.

 

[KCJackson]

With that aluminum housing how much weight has taken off compared to the NV5600?



That should go right to increased payload right?

The NV5600 was shown as weighing 132 pounds more than the 48RE. The G56 now shows 25 pounds less than a 48RE-equipped truck, for a total weight savings of 157 pounds over the NV5600.



And keep in mind that the 4. 10 axle is not offered with the Cummins/G56, but with 3. 73s, it has the same higher GCWR as a Cummins/NV5600/4. 10 driveline. So you save 150 pounds <B>and</B> get a more economical axle ratio to do the same job.

 

[QWaller]

I don't know about you guys but I like the thought of having that much more "meat" behind that much motor as is with NV5600 and the Cummins

 

[DBond]

And keep in mind that the 4. 10 axle is not offered with the Cummins/G56, but with 3. 73s, it has the same higher GCWR as a Cummins/NV5600/4. 10 driveline. So you save 150 pounds <B>and</B> get a more economical axle ratio to do the same job.

I don't think it will give better fuel economy. The G56 has a lower OD than the NV5600, so the G56/3. 73 is about the same final drive ratio as a NV5600/4. 10. 2100 vs 2130 rpm at 65 mph.

 

[DBond]

I will take it home tonight for a better test

Tommygun



Thanks for the info!

Any chance you put some more miles on it, and have any more comments?

 

[RJOL]

I don't think it will give better fuel economy. The G56 has a lower OD than the NV5600, so the G56/3. 73 is about the same final drive ratio as a NV5600/4. 10. 2100 vs 2130 rpm at 65 mph.

This will be disappointing... One of the reasons (not the main reason) I bought a new truck was to get out of the 4:10 gears I had. Oh well...

 

[Tomeygun]

Tommygun



Thanks for the info!

Any chance you put some more miles on it, and have any more comments?

so busy, have not yet... sorry

 

[LHolland]

11.5" axle ?

Tommygun, Is the 11. 5" axle no longer available? For grins I went to the Dodge website and spec'd out a truck like mine. My sticker shows an 11. 5" rear axle with 3. 73's and ASD. When I spec'd an '05 it showed a 10. 5" axle. What's the word on that. Thanks

 

[Tomeygun]

Tommygun, Is the 11. 5" axle no longer available? For grins I went to the Dodge website and spec'd out a truck like mine. My sticker shows an 11. 5" rear axle with 3. 73's and ASD. When I spec'd an '05 it showed a 10. 5" axle. What's the word on that. Thanks

As far as I have seen, all diesels now get the 11. 5 axle



The gassers get the 10. 5 axle, thats why it shows up as standard

 

[RJOL]

I've taken the info provided about the G56 and I'm beginning to wonder if this is the setup I want. My 2001 had the NV4500 5 speed with a 4:10 axle. Its highest gear, 5th, was rated at 0. 75. The NV5600 has a rating of . 073. The new G56 has a rating of 0. 79. One of the reasons I'm getting a new truck is to get rid of the 4:10 axle and get into something that is more economical for daily driving. I'm beginning to think that the G56 will be more like a NV4500 4:10 setup in its highest gear. Maybe I should be looking for an early 2005 or 2004. 5 with an NV5600...

 

[PDM]

Sounds like it's time for Dodge to bring back the 3. 54 ratio for this transmission.

 

[Jengle]

Hey Tom,

How about some full rip 1/4 mile times with it, or some dyno numbers?



Will it hold up to a 2000rpm clutch pedal sidestep?



Got a potential buyer on the line, if it looks solid enough. He has been beating on mine, while I was away on work trip. Said a Hemi took him off the line, until he got to 3rd gear and then it was show over, and eat my soot. :-laf

 

[dhill]

Right now mine is in storage in Mexico waiting for a green card so it can live here in Oregon. I really wanted the 3. 55, but that won't be available until we start whinning really loud and then it will be too late for me. I guess it'll have to settle for a set on 19. 5's from Ricksons.



Dave