I had almost locked a trade on an 01.5 HO 6 speed a little bit back, but things have since gone a different way and I will not be able to get it. However, I'm still wanting the 6 speed, and since my current 5 speed is ready for a rebuild, I thought about upgrading possibly. The constant shifting does not bother me one bit, I'm used to twice the gears in a semi. I just don't know which one to go with. The G56 availability is very nice, whereas the NV5600 is scarce. I just don't know how hard it would be to put either one in. Any of those that have done this swap, feel free to post any problems/concerns with the tranny, and how you like it. Either way, when the tranny comes out of the truck, it will be getting a DD clutch. The input upgrade to the 4500 will be done in addition to full synchro/bearing replacement if I decide to keep. Thanks.

 

Im going to be watching this thread carfully because i am really curious about G56 swap into these older trucks.

 

If you're going to be cranking up the power, the NV5600 has a mature aftermarket as far as clutches and such.

The G56 is building a good rep for itself, but it has pretty low ratios and not as much clutch selection available with the dual mass flywheel. The G56 shifts better than the NV5600, from what I hear. At least reverse is in the right place on the G56!

 

I just did this on a 2wd and I don't think it would be much harder on a 4wd. DD clutches are available I have 3:54 gears and the gearing works out to 150 rpm more in 6th I haven't drove it yet do to all the up grades I have done and now I'm building a dual filter air box and waiting for some elbows.the truck should be done this week.

 

I did a NV4500 to NV5600 swap. Wasn't too difficult. The biggest part of the project was lengthening the t-case shifter rod under the truck and having both driveshafts remade. Don't know much about the G56, although I had heard that aftermarket clutch companies were now offering a replacement flywheel that wasn't a dual-mass along with their upgraded clutch. Can't remember the name of the company that was doing it though, sorry.

 

one thing to keep in mind with the G56 would be T-case compatability, It may work fine but could create a few additional issues. I know a a few people who have done the NV4500 to NV5600 with little difficulty.

 

I say go with the G56. There was an article in one of TDR's issues where Bluementhal tore one apart, and not only did the parts look just as beefy as the 5600, but it looks a lot less complicated. Parts should be cheaper too. I've driven one before, and it does shift a lot nicer than than the 5600. If you go with one of them, try and find one out of a wrecked 6.7cummins, I think they have a overdrive ratio thats much closer to what the 5600 has.

 

I had another one apart in the shop last week:



What would you like to know?

 

well would changing out the old 5 speed that i have in my 01 be an easier swap to the G56 since it is a 2wd

 

By far, having a 2WD makes for an easier swap. Only things to worry about then are tranny crossmember position and transmission output.

Might even be able to use the driveshaft from the donor vehicle if they are the same length.

 

you can buy ALL the same aftermarket clutches for a G56 that you can for a NV5600...pretty much all the kits change it to a single fly wheel vs the dual mass flywheel that is stock on the G56. but I would not say the G56 is lacking clutch choices you can run any clutch and brand you want...my vote for the swap would be the G56 mostly cause the NV5600 stuff is getting hard to find or not even being made any more.

 

Besides, I've found the G56 to be quite beefy & well-engineered on the inside:



... even if not always very well manufactured.

 

This is how I did the cross member and the drive shaft is 3.5 inches longer on the front half of two piece. but measure any way I all so used the stock rear rubber mount. Ill post a pic tonight under the truck.

 

hears the g56 installed