I'm a first gen guy, I know nothing about these newer trucks. I'm looking to get something newer for the creature comforts.

I'm contemplating getting an 03 2wd 3500 dually with automatic. I don't know the mileage on it yet, going to call about it tomorrow.

My first question is how are the autos in these trucks? Do they go out often with the motor in stock form? I will not be pulling anything super heavy like a 5th wheel or anything, just an occasional car on the car trailer.

Second, what kind of mileage should one of these get? I'm used to my old trusty 1st gens, how do these compare? I know they have a LOT more power, just curious about the mileage.

Is there anything specific to look out for on these trucks? I know the 4wds have steering issues, but do the 2wds?

Any help would be greatly appreciated. Thanks.

 

The 03 and early 04 were good for milage, but do not respond to power adders as well as the 04.5 up.

The tranny, if taken care of, should be ok, but they are prone to TC issues and bands that need to be adjusted about every 50k for moderate use.

Mileage on it should be pretty good, 19-23ish, depending on conditions. 03-early 04's had different pistons and injectors, and a lower HP rating.

I'm sure that it has already been replaced, but it came with a canister mounted fuel pump that has almost a 100% failure rate. If it has one, I'd replace it now with the in tank retrofit if you want to leave it stock, or a raptor/air dog. (better choice, probably cheaper)

The third gens have a lot of issues with AC blend and recirc doors, a lot of people just rip it out when it fails.

That's all I can think of off the top of my head... I'm sure there is more.

 

The 3rd gen 2wds have rack and pinion and handle like a car - no issues. I have a 4.10 rear and my absolute worst mpg unloaded is 18.3 - city, summer, AC always on and I've gotten 22.2 putzin around sightseeing in the Co. mtns. I averaged 12.9 towing on that trip to Co. I think an auto will be either a ~SO 250 hp/47re trans (early 03) or HO 305hp/48re (mid 03+) but there were some production overlap variations like SO/48REs but I don't think there were any HO/47REs. A digit in the vin will probably indicate which trans but I don't know how to tell. The engine tag on the upper, front, left corner shows the hp - 305=HO. My stock HO really needed help to widen the power band and the top end power. The turbo change fixed the power problems completely and a 4" muffler helped the egt. The turbo change alone made it a completely better truck to drive. Craig

 

I've got the best truck I've ever owned right now. This dually (one of 4 I've driven in the past 20 years) pulls our 40' 5th wheel enclosed car trailer like it isnt there. Mileage is great empty and very competitive when fully loaded. The trans gave up (roasted the front and forward clutches racing it downtown) but I had the Banks 6-gun tuner with speedloader add-on turned up to max. My 4:10 gears are there for hauling and I have another open trailer about 26' long I use for lumber, trash, gravel, etc. and mostly drive back and forth to work (60 miles round trip every day) averaging over 22-24 even with the lunch hour devoted to a quick burger run thru stop lights and stop signs.
I bought it a few years ago when it had 31K miles on it from a Sacramento Chevy dealer (trade in on a new Chevy no doubt) and now I'm pushing 188K without any issues. The lift pump went south 3 times while under warranty and when it rolled 100K and broke the 4th time, I installed a home made stainless adapter to the stock filter canister to take the place of the stock lift pump and hung two holleys down on the frame rail. No problems since then and a solid 12-14 psi at the injector pump all the time loaded or empty.
The first set of tires went out at 112K and my new Pirellis are still being stopped by the original pads. Yea, I don't believe that part either.
Oil changes around the 3-5K mark and trans is maintained as well at same time, fluid and filter.
I haven't had a single issue with the engine except when I was off road hauling some wood a limb or rock bent the cranshaft position sensor and I had to replace it with a new one. Talk about bad luck, how often does that happen?
I cut off the CAT and kept the muffler and those 6 inch stainless stacks are maintenance free. Lots of room althought I think I would like the mega-cab rear seat and doors better but what the hey, I drive... so I don't care. LoL
I think you'll love it if you make the change and are a s lucky as I was to get a good one and not a lemon that's been abused and hot-rodded.

 

The 03-04 HO engines were the end of the good ol days in some ways, considering it didn't have any egr/ cat setups, and mechanical wastegates. Yes it does cost more money to get power out of them, but I have seen many high hp 03's and 04s, some record holders. They are great runners and are what I like to think of as a new age 12 valve. 25mpg can be had in the right driving conditions. Canister mounted fuel pump is the main flaw, fix that by replacing it with a stock intank kit or fass/ Airdog or of some sort.

 

I bought a new 03 early that year.

In the beginning, if you wanted an auto it was 47RE and the SO/CA emissions engine with a cat.

Later in the year the 48RE came out. It is apparently a stronger version of the 4 speed auto, and it could be had with the HO (no cat). Also came with the bigger 11.5" rear axle in 3.73 or 4.10.

I went stick shift 4x4 3500 SRW w/3.73's and it could do better than 21 hand calculated.

The filter mounted lift pump has been known to go out, but it generally just stops the truck (as opposed to taking out the injector pump). If replaced under warranty, it would have been converted to the in-tank pump used in later years.

Injectors are expensive. Make sure it idles smoothly, and starts easily.

HVAC blend doors and other mode doors breaking is a frequent topic on the 3rd gens. Make sure climate controls work in all modes and temp control works well. You have to evacuate the AC system and remove the dash as an assembly to remove the HVAC case should it need repair.

Also check ball joints, wheel bearings and the usual stuff.

Anyway, I think the 03/04's are among the best trucks to own, before emission stuff started cutting down MPG. If the 03 I bought would have been a dually (went big 5th wheel) I'd still be driving it.

 

Thank you so much everyone.

 

Ok, so it turns out that it has 208K on it. They're asking a good price I think, right at 10K. I'm just worried about the tranny and stuff. Is there any real way to tell of emanate failure soon to come? Should it shift sorta hard? Just slip into the gears? I've never driven a newer auto. All I have ever owned were older 5 speeds.

 

If it's like other autos... I'd check the fluid for color and smell and make sure it shifts right when it's cold as well as hot. Autos sometimes shift sloppy when cold cuz internal seals contract and loose pump pressure and get better when hot. Check for any leaks too especially front and rear seals. It's probably a crap shoot with any auto with 208k. Craig

 

I have a 03 2wd dually with 260k on it. It is pretty much stock except for the a/filter and the muffler. I have had the trans done at 250k because of the converter bolts coming loose and damaging the flex plate. So with the trans out I had it rebuilt, a new VB and a new converter. Other than that I've put t-rod ends, both front hub/bearings,walboro 392 fuel pump, u/joints once and the limited slip and r&p. I don't tow heavy with it. HTH

Jim