Dodge Cummins NV4500 to G56 - DONE!

[Route55]

Sometimes I love engineers. 2 and 4 wheel drive G56 units appear to be the same. 2wd units just get this big flange.

And sometimes I want to take a rolled up newspaper to engineers. There is only one sensor on the trans. I wanted to see if it was a reverse sensor or vss. It (and most of the bolts on the trans) are inverted torx metric. Bad engineer.....swat swat.....go to your corner and think about what you did.

It's a reverse switch by the way.

 

[charlieaarons]

Torx sockets are commonly needed to work on a Mercedes truck. An excuse to buy a set.

Charlie

 

[Route55]

NV4500 (left) vs. G56 design. You can see the spacer bump that is part of the 56 setup. This is what makes up for the difference. As you can see, the starter gear is at the back of the flywheel to make the difference. The only other way this could have been achieved would have been to use an aftermarket 13 inch nv4500 flywheel with a crank spacer, but then I'm not sure what kind of starter issues I'd have, and whether or not the starter would engage.

 

[Metcalf]

Great project!

Could you expand on the details about the 2wd/4wd transmission possibly being the same unit? What is the spline count on the 2wd unit? Is it any different? I think the 4wd unit is suppose to be 29 spline.

Also, could you take a few length measurements of the transmission and bellhousing plate on the engine. Getting this documented will help others down the road.

Great job on the project so far! Good documentation also.

 

[Route55]

As a reference point, I measured with a straight edge from the bottom of the frame to the middle of the output, which came out to 6 1/2 inches. Being this is a center bearing truck I'll need to stay close to that.

 

[Route55]

Great project!

Could you expand on the details about the 2wd/4wd transmission possibly being the same unit? What is the spline count on the 2wd unit? Is it any different? I think the 4wd unit is suppose to be 29 spline.

Also, could you take a few length measurements of the transmission and bellhousing plate on the engine. Getting this documented will help others down the road.

Great job on the project so far! Good documentation also.

As you can see in the one pic, the six bolt holes exist for a transfer case in the 2wd unit. As for spline count, I haven't removed the flange. I might when I get it in, so I'll get back with you on that if I do.

Trans measurments:

Bell to six bolt area (where a t-case would go) 29 inches

The face of the flange sticks one inch out, making 2wd bell to flange length 30 inches.

NV4500 adapter thickness 2 3/8 (ish)

So, entire length of my setup is 32 3/8 inches.

Stock total trans length for my 1997 2wd NV4500 without adapter is 32 1/2 inches from bell to end of slip yoke output.

 

[Route55]

Stock shifter and boot. I'm hoping to use the 2011 boot, because this one looks like Dom DeLouise would use it as a hat. Shifter is in neutral position, and you can see the way it bends up towards dash. The six speed shifter is different, more of a straight rod to the driver, so I'm hoping to be able to use it to give more dash to shifter clearance so I can mount my CB there. Currently it would hit, so CB is under seat, making it a pain to use. We'll see!

 

[Route55]

For anyone pulling a stock 97 shifter boot, here is something interesting - I unscrewed the boot but it wouldn't pop up. I even tried prying it. It took me a bit, but I figured out they use a boot inside a boot, with the inside one screwed to the floor and the outside one screwed to the inside one. Mine were quite stuck together and appeared to be one piece.

 

[Route55]

I needed a big trans jack (for use under a hoist) but couldn't find one in time, so I bolted my floor one to the top of my 1940's pneumatic air bumper lift. Quite redneck, but worked very well.

 

[Route55]

And the NV4500 next to the G56. Quite a size difference. The shifter comes out in the exact same spot to the inch. Reverse light hookups are different. The bellhousing on the G56 is much larger and deeper.

 

[Route55]

Southbend NV5600 vs. Stock clutch.

New flywheel came with longer bolts, which were necessary.

And new flywheel and clutch installed. Everything was super heavy.

 

[Route55]

Trans went in easily by jacking up front of motor. Contrary to what I read online, floor modification was not necessary.

 

[Route55]

I pulled the flange to see if it indeed is the same as a 4x4 version. It is. The output spline is 29. I also took a spare 4x4 case just to "be sure" and it bolted right in with plenty of spline engagement. So yes, 2wd and 4wd G56 transmissions are the same. And, 2wd and 4wd dodge crossmembers are interchangeable.

Bolting up

And in, but its not staying. Nice to know a 4x4 conversion wouldn't require a trans change.

 

[Heavy44TRT]

Great pictures and info. You will be on the road again soon. Looking forward to your comments on towing with it.

 

[SChandler]

Thanks for the info, research, and for posting it up here. :victory: Looks like I'll be able to keep my NP205 when I swap a G56 into my truck after I win the lottery. And I won't even need a 4x4 version of the G56 to do it with.