quicksilvr

Sorry for the newbie question, but I came across an 02 5 speed truck that will not last past today and I am curious what the differences are between the two.

Thx,
Eric

jp8819

High output 245 hp 6spd and 235 standard output 5spd final gear ratios are same I beleave just bigger jump from second to third in between gears on 5 spd.

quicksilvr

How about things "under the skin" like engine internals, final OD ratio, rear axle, etc.?

TIA,
Eric

Busboy

Axles ratios are the same and top gear on each are the same just more shifting through the gears. As already noted 245 to 235 HP. Engines are the same just different injector pump models. If you tow big and heavy a 6 spd might come in handy but if you are light (10000LB) then the 5 spd is all you need.

jmd025

higher compression ratio on HO 6speed models. 5 speed SO model respond better to performance mods. Different injection pump specs as mentioned. Different Computer programming between the two also.

quicksilvr

Anybody know about the rear axles 70 or 80 and jmd do they respond better because of the lower compression? One last one does anyone know if the 5 speed internally will hold up to mods like the 6 speed.

You guys are the best!

jp8819

Plenty of high hp 5 spds running around out there and parts for the 5spd are easier to come by as well. Either way you really can't go wrong.

quicksilvr

How about the axle?

jmd025

I think its a combination of the lower compression ratio, and the internals of the injection pump as well. Standard output can flow more fuel I believe. Somebody correct me if I'm wrong. I know I have seen HO guys go to a SO pump when they start getting in the higher horsepower levels.

As far as the 5sp vs. 6 sp, They are both strong, up to a point. NV4500s are cheaper to build with upgraded parts.

All of the manual 24valves should have a Dana 80.

dieselman2300

5 and 6 spd trucks are usually dana 80s.
Dana 70s came in automatics.

wadecool

Quicksilver, my advice to you is to hold out for a 6speed truck. There are a LOT of things that can go out with a 5speed tranny. I'Versailles replaced 4 of them in my truck. How much towing are you doing & how heavy? Are you going to add any performance mods? How good is the deal on this 5speed truck? I love my 01, and I got a great deal on it, but if I had it to do over again, I'd get a 6speed.

Tate

HO's respond better to injectors, as the stock HO injectors are very small, smaller than the ones in the SO engines. SO's respond better to electronics, because, as mentioned, the SO pumps will flow more fuel.

5 spds are cheaper to repair when needed, are just as durable as the NV4500's, and they shift smoother. I wouldn't turn down a 5 spd truck unless you really need that extra gear.

wadecool

Tate, the nv4500 is the 5speed, nv5600 is the 6speed. I don't know the differences in repair costs for 5spd vs 6spd. I just know my truck lost several 5spd trannys for multiple reasons (5th gear nut 3 times, exploded countershaft bearing, broken shift fork, etc). From what I've read, the 6spd doesn't have anywhere near the problems.

Checkmate

6 speeds cost alot to repair since they are no loger made and alot of guys ate up the remaining ones doin 5 to 6 speed swaps.

AH64ID

Both the 5 speed and the 6 speed are made by the same out of business company, so unless I am missing something parts are hard to find for both..

I love the extra gear between 2nd and direct, really great when towing and driving dirt roads, towing or not.