G56 or NV5600 which is stronger?

[NScott]

Which transmission will best stand up to heavy towing? I don't want to start a pi**ing contest here, just want want honest opinions, because it might help determine which year of truck I may look for to buy. Is it true that some of the late 05's had the g56?

 

[steved]

Most 05s had the G56...



Knowing what I know now, I would opt for a G56 truck since they are easy to get parts for and seem to be standing up fairly well...



From what I have read, the NV5600 is stronger... but for towing I doubt you'd really notice a difference.

 

[rbattelle]

I don't want to start a pi**ing contest here,

Brother, you just did!! :-laf



Honestly, determining which is "stronger" is probably very hard to do, as it depends on your definition of strength.



In terms of likelihood of stripping out a gear? They're probably equal.



In terms of likelihood of snapping off a dog? They're probably equal.



In terms of likelihood of bending a shift fork? They're probably equal.



In terms of snapping a shaft (any shaft)? They're probably equal.



In terms of case strength, however, I have to give the nod to the 400 lb of nodular iron of the NV5600 over the aluminum G56. Does a stronger case matter? Maybe, I'm not sure.



Someone who has rebuilt both types would be best qualified to answer this question.



Ryan

 

[Gary - K7GLD]

I was openly leery of the G56 when they first came out, and a few DID have problems - but at this point, I'd feel perfectly comfortable with either one. You really don't usually see breakage failure issues with either, other than those seriously stressed or abused.

 

[MScheiper]

I have both. nv5600 in my 04. 5 and the G56 in the quad cab. Got about 60,000 miles on both trucks. My nv5600 I like a little better for towing. My RPM's are lower with the gearing (w/3. 73 in the rear end)in that truck than in my G56 at highway speeds. Little better economy. G56 shifts slightly easier. Shift gates are closer on the NV5600 than on the G56. NV5600 can be a little "grumpy" shifting, especially when it is cold otherwise its great! As far as tough goes, I have to agree that the iron is tougher than the aluminum case, although I haven't been inside either, just drive' em. Have been happy with both and have had no troubles so far... ... knock on wood

 

[Cattletrkr]

G56 gets my vote even though I've never driven one.

My NV5600: https://www.turbodieselregister.com...ions-2003-2007/187608-looky-what-i-found.html


Those plastic gears and paper (cardboard) synchros in the G56 may cause a problem down the road though.

 

[Grizzly]

I personally like the bullet proof NV5600 for heavy towing. When the G56 first came out in early or mid 05, they had problems.

 

[steved]

I personally like the bullet proof NV5600 for heavy towing. When the G56 first came out in early or mid 05, they had problems.

Those early G56s had issues because they were not filled with fluid from the factory though... can't blame that on the trans...

 

[Grizzly]

Those early G56s had issues because they were not filled with fluid from the factory though... can't blame that on the trans...

Some were leaking fluid, badly. That all got resolved soon, however it did stop production of trucks equipped with the G56 for a short time.

 

[Bob V]

The G56 should run cooler with the higher fluid capacity (12pints compared to 9. 5pints) and the aluminum case dissipating the heat. Either transmission will hold up fine, some parts for the 5600 have been hard to find.

One other issue is the flywheel. The G56 has the dual mass flywheel. There have not been much problems with this yet, and I think that time will prove that it works fine. I have seen this clutch/flywheel hold more HP than the 5600 clutch. However, since the flywheel is a moving part it is a wear item and can go bad. Usually in the form of a vibration with engine speed.

Don't let the transmission be the deal maker/breaker, if you find the truck you like, buy it. If you found two the same I would go with the G56 with the better parts availability.

__________________



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[Regcabguy]

G-56= easy shifter for "shift retarded"

If you've got a wife that's "shift retarded"(she almost destroyed the transmission in my Toyota due to the location of reverse) go with the G-56. My spouse could immediately shift this sucker perfectly. My buddy with a '99 and a NV5600,drove mine and within a mile smiled at me and said "I'm already used to it!"

 

[JCasper]

I have an NV5600 and from what I have heard I wish I had the G56.



Most people say they shift smoother

 

[Motorhead]

I have driven both and the G56 is a much smother trans in my opinion. I agree that the iron case has to be stronger than the aluminum. The main thing I look at is future parts availability. The G56 is now used with the 6. 7 and if they keep using it, I see it as an easier trans to get parts for or to find good used.
The early G56 had a . 79 6th gear where as the NV5600 had a . 72 6th. That makes a difference on the freeway. BUT, If you want to run big tires, the . 79 might be good. MY $0. 02
I wouldn't let either or affect me though if I found a good used truck I liked.

 

[SSalzer]

When I bought my truck, a friend who works for Dodge told me "Do not buy a truck with the G56!" I'm not sure if that's because they where having trouble with the dual mass flywheels on the earlier ones or not. Everything I've read states how the NV5600 has been around for so long and it's proven to be bullet proof. (I'm sure you'll find a lemon every so often though). I have not had any issues with mine. My friend has one in his '02 dually and tows heavy with it almost every day. No issues there either.

I do have to admit that it is a little temperamental when it's cold though. Hope this helps you out.

 

[TCluff]

I RUN THE NV5600 IN THE 03 AND I WILL AGREE THE SHIFTING FOR A DAILY DRIVER IS HORRIBLE BUT I LIKE THE FACT THAT ITS A TRUCK THAT I HAVE TO "DRIVE" , BUT WHEN IT COMES TO TOWING HEAVY WITH 37INCH TIRES, THAT HAS GOT TO BE ONE OF THE BEST SHIFTING LOAD HANDLING TRANSMISSIONS EVER, 4:10 GEARS AND THE 5600 WITH BIG TIRES OR HEAVY LOADS IS AWESOME, BUT SMALL TIRES AND LIGHT LOAD ISNT VERY SMOOTH, I HAVENT DRIVEN THE G56 BUT IM LOOKING FOR A MEGA CAB AND WILL MOST LIKELY GO WITH ANOTHER MANUAL ALTHOUGH THAT NEW SIX SPEED AUTO SOUNDS GOOD TOO!!!

 

[AH64ID]

I have a 5600 and dad has a 56..... They both are great trannies... the . 79 6th in the 56 seems a bit better on towing in 6th thru the rockies... At 60mph I am only at ~1700 and the 56 is at ~1900... . but for empty cruising I really like the . 73 6th... .

Its a crap shoot...

 

[Southbound]

NScott-



So I got to chime in on this one as I have had both transmissions and I am currently running the G56. As far as durability I would assume they both have had issues over time. The one thing about the G56 is the gearing is a little different than the NV. You will find with the G56 your standard 3. 73 rear-end ratio will change to a 4. 11 type ratio which is great for pulling as it will put your motor at an RPM range equal to the "sweet spot" needed when pulling up hills on the highway. Obviously you motor will rev much more which might hamper your gas mileage but the post I have read over time it appears that really isnt a major factor??? I can tell you that your top-speed will change a bunch but I didnt buy the truck to pull over 90mph. Lots to consider but if your going to use this truck to pull I really think you will like the gearing much better in the G56. Note: I like both so not trying to sway you one way or the other. Simply pointing out the differences.



My . 02



Southbound

 

[sonorakitch]

I think you would be fine with both. Both manual transmissions have their advantages.



But one thing... what the heck does case strength have anything to do with the longitivity/HDness of the transmission? Unless you are rockcrawling and high center on a boulder, I wouldn't think case strength would mean much. And the aluminum does dissipate the heat more efficiently, and is lighter... saving an average of . 0138 MPG .



~Chris

 

[CumminsBu]

I think you would be fine with both. Both manual transmissions have their advantages.

But one thing... what the heck does case strength have anything to do with the longitivity/HDness of the transmission? Unless you are rockcrawling and high center on a boulder, I wouldn't think case strength would mean much. And the aluminum does dissipate the heat more efficiently, and is lighter... saving an average of . 0138 MPG .

~Chris

No kidding, don't forget the Aluminum bell housing between the engine and NV5600. At first I was a hater but now I would drive both. If my NV5600 craps out on me I might try the G56 in my 2003

 

[Radshooter]

When our NV5600s finally bite the big one and we can't get parts anymore... ... . How hard is it to swap in a G56???