hey guys, i don't hang out much in the 3rd gen area since i have a 2nd gen... however, i'm looking to upgrade to a 2003 or newer (looking more towards 05-07)...

what are some things i should be looking for? from what i've read there is a little difference if i go with a 6-speed as far as final gear to look out for... help me out on the rest of the gotchas

 

I sold my 01 6 speed and picked up an 03 auto about a year ago. I did a ton of research when I bought my 03.

I have been very happy with my 03 and have had 0 problems with it.

Had some minor stuff with my 01. Was on its 3rd lift pump, vacuum pump seals, a couple tie rods, and an oil pressure sending unit. That was over two years and about 25k miles.

Seems like something changed every half year in the 3rd gens

03 - HOs (305hp 555 ft lbs) only in 6 speed, till about January 03 when 48REs came out and HO with automatic became available. This is what I have.

Early 04, the only change was the different steering wheel and you can use the cruise to control a high idle. Also, the autos come with Tow/Haul but it just locks out OD.

SO were available in 03 and early 04. Only way to get california emissions. They have the 5 speed or 47RE, but began using the 48RE in January 03. They also have 10.5 rear end as opposed to the 11.5. I think the SOs were 235/440 in california trim or 250/460 in std trim. SOs just have detuned computer programming, so a programmer brings the power up the same as the HO.

January 04, the 04.5 "600s" come out with 325 hp and 600/610 ft lbs.

For 05, they switch to an intank lift pump and some trucks have the plastic intercooler which can be problematic. This is the first year for the Tow/Haul function that works like the Allison, however there is no OD lockout.

Late in 05 they offer the G56 manual tranny. I've driven a few and I personally like it better then the NV5600. Smoother shifting and better ratios IMO. .79 vs .73 sixth is better for towing, but not for mileage. Also, I believe when the G56 came out, they eliminated the 4.10 gear option. Although I could grab 3rd faster with my NV5600.

06 brings the new headlights and new interior. I like the headlights better but I like the 03-05 interior better. They also have Tow/Haul with OD lockout.

Late in 06 they did some electronic changes that effect being able to use the TST module.

07 brings new 2500/3500 emblems and that is about it. However, late in the fall they switched 6th gear from .79 to .74.

I think that is about everything for the 5.9s.

Late 07 the 6.7 comes out with the very sweet 6 speed auto, but not so sweet emissions crap.

08 they offer the 3.42 ratio with the 6 speed manual as well as the 3.73s

I like the manual for heavy towing but I couldn't shift fast enough and like the auto better overall.

Just my 2 cents

 

The 2004.5 and up have a cat and a third injector event for emission control and a slightly bigger turbo. Better milage on early 2004,and no cat. If an exhaust brake on an auto is important then move up to the 06.

 

Look out for the plastic intercooler on the early 05's they are ok if left stock but will eventually fail on a modded truck.

 

I just went from a 98 12v to an 03 and I must say its pretty nice, I still like my 12v but the comforts of the new truck are nice expecially with the 4 door with the family, I kind of like the idea to be able to turn it up and turn it done with mods and the programers. I even get a little better mileage. I had a 5 speed in the 98 and a 6 speed in the new one, I am not sure which I like better yet. Other than I don;t have the gap between 3rd and 4th on the 6 speed but I can shift faster with the 5. the 3rd gen stops better I don;t have to deal with the track bar issue. I like the 3rd gen to use and drive to work and with the family but I LOVED the old 12v 5speed for hot rodden around.

 

thanks guys, keep the comments coming

 

I loved my 97 5spd but love my 03 HO 6spd even more. SOOO much stronger clutch and trans and the CR breathes MUCH better so no skyrocketting egt at high rpm and wot. Also better cooling system. I also researched for 2 yrs before buying and didn't want a 325 with the emission garbage and 3rd inj. squirt. Build date 10-02 and none of the early 03 problems like vibrations or cracked alternator bracket. Biggest drawback is it took a decent turbo and muffler to wake it up but it was sure worth it. Craig

 

I also loved my 99, was my first truck. i traded it in on a '05 early this year and i am quite pleased. To this day i still miss my old truck but this new one seems to do everything better. If i can guarantee you you will be happy, the only thing i miss is the rattle of the 24v's.

 

how can i tell what gears a truck has... i think i found an 06, but dealer was closed