NV5600 vs G56

[KRob]

Hey Everyone.

I have some concerns about my NV5600 and i like planning ahead. So what i am looking for is a comparison between the two transmisions. If you can refer me to a previous thread great if not what alls the difference.

I know G56 shifts smoother and that the gearing is very similar but what about strength longevity ect, and getting parts and replacments...cost.

Also has anyone put a g56 in a 2nd gen yet.

THanks alot
ROb

[sofakingbad]

i personally like the nv5600 better....seems easier to go into the gears an i can shift it faster. if i member correct the 5600 is stronger....other than that i dont know much diff....becides R is in a diff location...

['strokeThis_'07]

Yea a guy on TDR swapped a G56 in his 2nd gen...

What concerns are you having with the NV?

I prefer the NV myself, feels better in my hand and shifts are more...precise I guess is the word.

The NV does seem to be stronger. First its an iron case. Seems some with the G56 have split the aluminum case over 650hp or so. There are some holding more, but its a concern.

Also the internal support is better in the NV. Apparently, when putting power through the G56, the shafts can flex enough that the teeth on the gears dont fully mesh and will break.

I have seen NVs break also, so nothing is bulletproof. These are fairly good guidelines; Im in no way saying the G56 will split at 650hp. Theres guys way over that. Jepling on CompD was running 850 or so on his G56...hes doing an NV swap last I heard.

The dual mass flywheel has been an issue for some. A new clutch and flywheel from South Bend can take care of that though. The G56 does seem to be a smoother shifter.

Parts availability could be a concern, as the NV isnt made anymore, and it seems parts may be drying up. Ive read from guys that needed stuff that had no issues finding them. The G56 is obviously still being made, so parts shouldnt really be an issue.

I wouldnt really call either one superior over the other. Theres issues in each

[KRob]

Thanks, for all the info.

I dont know if i am having problems or not any longer...mainly because i havnt seen the truck in 7 months and will not see for another 4 or so...i think.

But when i left i was having issues with it shifting...i think it was just me paying really close attention to how slow it shifted while cold and then frogetting about it when it had warmed up.

When you shift is it suppose to fall into the gear or should you have to force it a little?

I am also just thinking longevity of the truck. It will be in a barn for another year or two while i finish up a tour in Germnay/Iraq and i am just thinking about how much harder it will be to find parts. Its still a pretty new truck just over 100k. So i plan on keeping it.

THanks
ROb

['strokeThis_'07]

Occasionally mine needs to be persuaded to go into gear, but for the most part it goes right in without much resistance

[totalloser]

The nv5600 can be particular about oil, and has trouble dissipating heat due to the iron case. Iron is a miserable conductor of heat, aluminum is a fantastic conductor of heat. The nv can get hot enough to burn up non-synthetic. Mine had this problem when I got it, and it was literally impossible to shift once warmed up. Put the factory stuff in it, and it took about 6 months of driving to get it to what I'd call acceptable. It had dino gear oil in it-can't miss THAT smell.

Since then, I put Royal Purple in it, and it shifts a LOT smoother, now.

Also, shifting trouble can be caused by a dragging clutch or a damaged pilot bearing. Usually manual transmissions get broken or abused, not worn out.

[KRob]

Well i aint going to say that this tranny hasnt been abused. I would also believe that the clutch is getting old. I think i have a stock clutch with all the power mods so i am expecting to replace it anyway.