BOMBed NV-4500 or 1-3/8" equipped NV-5600?

[HoleshotHolset]

I have heard a LOT of people beating their heads against the wall over this issue...



Do you BOMB the NV-4500 or swap in an NV-5600?



Here's the big question:

Is there anything inside the NV-5600 that's better than a BOMBed NV-4500 (besides the better ratios... )?



Here's some quick numbers:

“Big Tex Big Meal Deal” (to completely rebuild it... properly. ) = $900

1-3/8" input shaft = $850



At this point - you're smack dab into used NV-5600 territory... .



Granted, you have to fiddle with the driveshaft(s), possibly the crossmember (depending on what you have under there to begin with, new 13" clutch, etc. , etc.



Matt

 

[jmeehan]

It depends on what your doing with the truck.

Towing, I'd take the 6 speed for the ratios.

Performance, I'd take the 5 speed, there's one less gear to row.



Bomb the engine, tow with the 5 speed and I don't think you'd miss the extra gear of the 6 speed.



Just my thoughts, everytime I'm in a hurry and rowing that extra gear.

 

[Jeff Clark]

I'll agree. If your 4500 is in good shape and isn't having problems, upgrade it. If you needed a new transmission, then I would say make the swap.

 

[HoleshotHolset]

I'm not worried about rowing through the extra gear... heck, back before I did the DTT in my '94 - I was shopping for 10-speed RoadRanger transmissions.



I like to do everything overkill to the max - do it once, do it right, 'fuuhgheddaboutit'.



The NV-4500 in my '98 seems just dandy at this point, but I'm always looking for the best setup...



Matt

 

[HoleshotHolset]

Let's talk hard parts in both of these trannies...



Which one has better hard parts?



Matt

 

[RT66DOC]

I've been wrestling with this dilemma, too. Like Matt said, once you start looking at the larger input shaft you're in 6-spd $$ territory. Every time I stop at a light I flip it into N because I'm concerned about the "little" input shaft and pilot bearing on the 5 spd.



Truth be told, while debating with myself over which way to go - bombed 5 spd or 6 spd swap -, I've been driving around with only 4 gears for over a year and more than 10K miles since 5th blew off. I could get on a rant about the whole 5th gear saga but I'll spare you. Suffice it to say the DC engineers really blew it IMHO. He**, since the truck was new I only towed ONE TIME - < 6000 lbs and that's when it let go. BTW, did I tell you my fuel gauge doesn't work either?



One thing's for sure, I don't see many posts titled "Darn! Lost 6th Gear Again!" from the ETH guys.



OK, 6-spd it is. Besides, I like to shift.

 

[HoleshotHolset]

I've been under the assumption that once you do the fully splined mainshaft - the 5th gear problem goes away, right?



Even if you install the fully splined mainshaft - you're still putting a Band-Aid on a transmission that is probably inferior to the NV-5600 in more ways than just the OD gear...



I'd like to find out what specifically is inferior inside the NV-4500 when compared to the NV-5600's innards... if I can find enough 'bad things' inside the NV-4500 that aren't as stout as the NV-5600... the choice to do the swap is easy.



Matt

 

[banshee]

this page has some good info about both trannies.



http://www.dodgeram.org/tech/specs/Ramspecs.htm

 

[HoleshotHolset]

I forgot about that page. der.



NV-4500

1st 5. 61

2nd 3. 04

3rd 1. 67

4th 1. 00

5th 0. 75

R 5. 61/'98+ = 5. 04



Synchronizers: Carbon fiber composite

4x4 Output shaft: 1-1/2" 29 spline

Max GVWR: 16,000 lb

Max GCVWR: 21,000 lb



NV-5600

1st 5. 63

2nd 3. 38

3rd 2. 04

4th 1. 39

5th 1. 00

6th 0. 73

R 5. 63



Synchronizers: It has 'em...

4x4 Output shaft: 1-1/2" 29 spline

GVWR: 16,000 lb

GCVWR: 26, 000 lb



If you go by the numbers above - the 5600 doesn't seem much more beefy than the 4500...



How about mainshaft/countershaft diameters, spline count, etc. ?



Matt

 

[RT66DOC]

Matt - You've got mail.



Compare the weights of the two gearboxes. Something must be beefier in there.

 

[HoleshotHolset]

Hey Tom,



Thanks for the 'mail...



Good point - even though the NV-5600 is only 6" longer than the NV-4500... it's 160 pounds heavier! There has to be something in there that's beefier... .



Matt

 

[RT66DOC]

Gerbils?

 

[Jengle]

Hamsters on steroids. Its the extra hamster food, they eat more.

 

[RT66DOC]

Right Jengle. I forgot about that. All those itty-bitty MREs. Gerbils go in the tailpipe.