Closer gear ratio basically. That and the 5600 is stronger than the 4500.
The 4500 weighs almost the same as the 5600...only difference being thicker
shafts, extra gears and such. They are housed in the same casing and use
same bell housing so it's not as big of a deal as you may think. Neither of
these trannies are fast shifters. Only difference is the 5600 is a six
whereas the 4500 is a 5 speed. So...it will indeed add value when coupled
to the supercharger and other items I'll be installing.
I coulda sworn the 4500 was an aluminum case, and the 5600 was cast-iron...
How? By adding an additional gear between low and 1:1, that you'll probably
just skip over anyway? I agree here - I don't see the benefits at all...
you're not going to put out enough power from a 360 to break the NV4500...
those trannies ran just fine behind some pretty beefed-up Cummins engines,
putting out way more torque than you could ever hope to muster with the 360,
and the only real problem was with the 5th gear nut backing off, due to high
torque at low RPMs vibrating the nut loose - another problem you won't have
with a 360.
No, the 4500 is cast iron as well. I won't be skipping gears
all the time. Believe it or not, there comes a time when some,
like myself can benefit from the additional gearing...like maybe
plowing snow. It's a big jump from 1st to 2nd on the 4500.
Also, the larger clutch will benefit on the plowing and with
I actually started this to see what sort of "input" people had
as to being able to make it happen....not as a request for
nay-sayers to shoot it down because "they" don't think it's
That being said, please lets limit the input to positive only on
this thread and if you want to post negatives...start a different
thread as a courtesy to me and others that may be interested
in possibly doing the same conversion. TIA.
Closer gearing between 1st and 2nd is the biggest reason. Also,
I feel the clutch on the 5600 (13") will be better suited and will
give me more miles. I also will be starting to pull some pretty
heavy loads as well.
I am interested in the thread for my own project.
So, for comparisons sake a 5600 weighs 360lbs and a 4500 weights 250lbs wet.
4500 input TQ rating 460ft-lbs on a 1 1/4" 10 spline shaft. 5600 input TQ
rating 550ft-lbs on a 1 3/8" 10 spline shaft.
Then how can anyone say they're basically the same gearbox other then the
extra gear? When that's obviously not the case.
I did read the whole thread, I don't know what to say other than that is not
correct. The cases are not at all the same. The 4500 is a top loader
transmission & the 5600 is a rear loader. The only similarity there is that
they're both cast iron. So my question still stands.
Hhmm....good info I guess. But please explain what you mean by
endloader. It is my understanding that the differences are basically
in the bell housing, larger shafts and longer overall assembly which
will necessitate changing the lengths of the driveshafts.
4500 - everything comes out the top, shafts and all. Unbolt the shifter,
then the coverplate which holds the shiftrails comes off the top. The whole
top of the case is exposed.
5600 - You can't remove the top of the case. The rails and shafts come out
There's one link that was posted in this thread that shows pictures of both.
It's clear to see that each case is constructed very different.
That's what I thought you meant. The shifter comes out in the same
location on both trannies....that's the main point with regards to ability
to fit. Doesn't matter to me how it is disassembled...that'd happen
when it's out of the body anyway. The input shaft and output shaft
are in the same location as well so it should just be a matter of
modifications to a few parts to fit. From info that has been sent to
me so far, I may just need an adapter plate for the bell housing and
modify the lengths of the driveshafts.
I see what you're getting at now. You don't care how the cases are
constructed, just the physical size differences for swapping one with the
other. So when you said the cases are the same you were just ignorant to the
fact that they are not at all the same.
Your statement "The input shaft and output shaft are in the same location
as well so it should just be a matter of modifications to a few parts to
fit." I find pretty funny. So you want to try and swap internals from a 4500
to a 5600? Good luck with that. For starters the overdrive on the 4500 is
out the back of the main case. Thus the problem with the 5th gear nut
backing off. The 5600 overdrive is on the main shaft in the front of the
case. Then none of the gears would be swapable that would put the gear
ratios out. And the syncros, why would you even want to swap those.
Or are you just talking about modifying a few parts on the truck to be able
to swap them?
The 5600 is 5 1/2" longer than a 4500. So rear driveshaft needs to be cut
and front needs to be lengthened. If you use a pre-'99 nv5600 you'll have
the weaker version of it. it will have a 1 1/4" 12spline input shaft with a
12.25" clutch and a smaller pilot bearing. the 2000+ model year nv5600's
have an upgraded input shaft at 1 3/8" 10 spline that uses a 13" clutch and
slightly larger pilot bearing. If you end up useing a 24valve flywheel
you'll need the 3/4" aluminum spacer for the starter. Or use a 12valve
crossover flywheel (thats pre-drilled for the 13" clutch) then you don't
need the starter spacer.
Lots of people have done the swap, theres nothing new there. Myself, I'm in
the process of putting an '01 nv5600 13"clutch behind a '95 12 valve.
I follow you now. I got thrown off track when you started talking about them
being housed in the same case. I will be useing a crossover flywheel. and a
np205 behind it. This is all in my '84 crew cab Chevy, so I can't say any
thing to what else needs to be modified in a Dodge. But I believe the 5600
to be a good fit for the powerband of a 12 valve.
I have both. A 92 W250 and an 04 2500. Both are 4X4's. The NV4500 shifts
much easier than the 5600. Driving the 04 empty is a chore with the six
speed. The ratio splits are much better suited to pulling a heavy load.
Can't imagine how slow it would shift if the engine was capable of pulling
5,000 RPM. It's the 3-4 shift that's wide with the 4500. IMHO, they would be
well off coming up with a decent automatic.
In the 04 I find myself wanting to use 2, 4, and 6th. The owner's manual
says not to skip gears. Is this because they think we'll torture the
synchros? Or, is there another reason? Ironically, I never feel the need to
skip shift the 92. I view it as a HD three speed with overdrive and granny
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