bigsmokey

i am thinking of changing my automatic to a manual and was gonna go with the 6 speed, but i recently saw a thing online that says the 5 speed is more reliable then the 6 speed. It says the 6 speed has problems and they even sell a complete kit to change the newer trucks back to 5 speeds. Has anyone had problems with their 6 speed and should i go with the 5 speed instead. thanks for any info in advance.

Backwoods Bumpers

I've had one of each in my 24v's. I really like the gearing in the 6 speed, but look out when it's time for a rebuild. I got my 5 speed rebuilt for $800. That was with the shop taking it out and everything. When my 6 speed dropped, it was gonna be over 3 grand for a rebuild! My solution was to go to the dealer and by a reman G56. Cost the same as the rebuild for the NV5600. I love the G56. I even swapped it into my 06 since it was the newer version lol.

To answer your question (you'll get mixed replies), the general consensus seems to be that the 5 speed is more reliable, but both are good transmissions. Personally, I'd just get whichever one you find at a good price.

Tate

I swapped my 5 spd for a G56 in my 12v. Shifts smoother, and the gear changes are all pretty much the same (drops 25% RPM on each shift). That being said, a G56 isn't the strongest tranny out there, due to case flexing. There is ways around that though. But unless your >600hp, shouldn't be too much of an issue. If you decide to get a G56, look for one out of a 6.7, they have a better OD gear.

You don't hear too much good about the NV5600 other than they are heavy. When they fail, they fail big, you can't rebuild them nearly as easily as the 4500, they are out of production, so the G56 beats it there.

Backwoods Bumpers

Tate, I've got a buddy shopping around for a G56. Is that exactly the split? 5.9s have the lower 6th and 6.7 have the higher one? I wasn't sure. I just told the dealer 2008 to be sure.

.....and I apologize - not trying to hijack the thread!

rebal

I have a 5 sd nv 4500and a 6 sp nv5600
The 5sp is way nicer to drive in town
but the 6 speed is way better pulling heavy loads
the 5sp loose 5th gear if its not been up dated 6sp are notcy and I just had my 6sp re built to the tune of $3600 but it was only because the last time it got serviced it was not refilled with oil I never had any problem with my 6sp and I love it only towing I hate it driving it around town the 5 sp is nicer but if you will be towing heavy loads the 6sp is the way I would go
and there are plenty of parts out there for the NV5600 the shop that did mine got every thing in a couple days . I personaly feel that if your tearing up a nv5600 you need to learn to drive a stick! I tow on a regular basis 23,000 + and I have towed as much as 32,000 gcw with out a problem one with my 6spd but it wont hold up with out oil.

SIXSLUG

If you get an nv5600, make sure its had the proper fluid in it.
I'm not sure how to do this, but mine cost over $4000 to replace!

Kennys

The NV5600 has really gone up in price. I had problems with the 5 speed and ordered a new 6 speed for several hundred less than a rebuild cost now. I love the 6 speed, pulling loads the gears are perfectly spaced. It is a much beefier transmission, mine has 250k on it with no problems at all. The 5 speed trans. weighs about 180 lbs. and the 6 speed weighs about 420 lbs. I believe that if it is run with the proper lube it should last for a very long time. They don't shift as easy and they are noisy at low speed but I wouldn't change back to a 5 speed. Don't see how anyone could test one any more than I do, usually gross 25 to 35k lbs.

bnold

Parts are available for the 5600 again, aftermarket is producing them now.

Rebuilds right around $1000 depending on parts required

SIXSLUG

Mine ended up being replaced because the PO had the wrong fluid in it and we couldn't get the gears off the main shaft with an 80 ton press.
Parts weren't hard to locate and a brand new trans was had in a day from Seattle.

DieselRebel24

i love my 6 speed. iv droven a couple buddys 5 speeds even before i had mine and would never have a 5 speed. there better than an auto don't get me wrong but the 6 speed is way tougher

SIXSLUG

Another thought for your consideration, Big:

The 6er is great for towing and highway type duration driving, remember 5th and 6th are the same gear ratio in the nv4500 and nv5600, you get a closer spread with the 5600.
Around town I'm rowing a lot to stay in the 25-35 mph speed limits to stay in the good rpm range with my 3.55 rearend. A 5ver I used to drive had a good range throughout 4th gear for these speeds. Take your rearend ratio into consideration on your choice.
I don't know what the 5 speed had for rear gears.

Tate

4th in a 5 speed is the same as 5th in a 6 spd.

For 25-35mph, 4th gear is **** near perfect.

Barndog8341

Totally depends on what you are using the truck for. Except for the 5th gear problem, the 5spd is an excellent transmission, and simple to rebuild.

If you are going to be towing, I prefer the 6spd, just for that one extra gear. The shift from 2-3 on the 5spd with a big load will kill you. With the 6spd, you have 2-3-4, much easier.

Some say the 5 is easier to drive than the 6, and that is probably true, but I'm guessing that's because it's got one less gear.

I've had both. I preferred the 5 in town, the 6 for towing.

Bottom line:

Towing - go for the 6 sp
Everyday/Town/Some Towing?Mix/Etc.. - get the 5spd, and make life simpler

nothingbutdarts

heck, around town who uses all 6 gears anyway, I always skip a gear or two and unless on a big hill don't start out in first.

6-speed here.

bigsmokey

ok thank you for all the input sounds like i just need the 5 speed i don't do heavy towing its mostly a daily driver with some minor towing (just a couple of 4 wheelers) I just find myself manually downshifting my auto all the time when coming off highway or climbing hills so i think i would be better with a manual so i can really choose what gear i wanna be in. I also like the peace of mind with a manual don't really need to worry about temp. thanks again.