Differences between 2003, 2004, & 2005 engine & auto transmission?

[GOT-Torque]

Can someone help me out with determining what the major differences are between engines and auto transmissions in these three years?



Thanks!

 

[Suprmn]

Here is my basic understanding and others can correct me if I am wrong. The early 03's have I believe a 295HP motor and the 47RE trans. These should have a build date in 02 or early 03. Somewhere in 03, they switched to a HO motor at 305HP and 555TQ and the 48RE trans. These will have a build date from early 03, probably JAN, through the later part of 03. Somewhere in 03, the model will switch to an 04, but is still the same truck. As of Jan 1, 2004, the HO motor went to 325HP and 600TQ, still with the 48RE trans. This change date is firm to comply with the new emmission requirements that went into effect. These trucks are known as the 04. 5's, and will have build dates from Jan 1, 2004 on, maybe a few done in Dec 03. There are several differences including the addition of a catalytic converter and the post injection event in the fuel injection which some say is taking the fuel mileage down.

 

[HOBrian]

1 thing to add... In early 03 you could get the HO 305/555, but it had to be the 6 spd. Later in 03 they had the 48re (as stated above)

The transmission has had some different software changes. The tow/haul mode has change. I do not know the specifics. (I have a 6 spd).



Hope this helps. Oo.

 

[KKlepfer]

Difference between 03 and 04. 5: 305hp/555ftlbs vs. 325hp/600ftlbs



04. 5 has: Catalytic Converter, post injection, ECM has 550 Kilobytes of code (03 has 350Kb of code), cylinder head ports have less swirl, High cobalt stellite valve seats, high strength iconel valves, exhaust manifold material and shape is changed for durability, multi layer gaskets between manifold and head, piston bowls are slightly more open, larger compressor wheel and housing on HY-35 turbo, wastegate is electonically controlled, and improved oiling on turbo shaft bearings.



I believe these changes were made so the engine could run hotter thus making the catalytic converter more effective. All for cleaner emissions. The by product was a little more hp and torque.

 

[CharlesKennedy]

plus the ECM memory issues (and the friction ring) for the auto trans J brake. and the fact that the 05 does not have the tow "lockout" butten :-{}



The 04. 5 does not have enough memory to upgrade the ECM plus does not have the friction ring (fix) "I think"



The 05 has the ECM and friction ring fix - but no plans to "let" people have the toy! :{

 

[GOT-Torque]

So the 48RE transmission only came behind the High Output engines? The 2003 standard engines only came with the 47RE transmission's?

 

[RDyson]

My 03 was built in Oct. of 02. It is the standard output engine rated at 250 horses with the 47re. The 305 engine came out later in 03.

 

[Kvic]

My '03 was ordered from the factory, and delivered to us in may of 2003. It is a CA motor, 235hp, 460tq, our transmission is the 48re.

 

[MFalkinham]

Late '03 SO trucks have the 48re. I believe the factory used up the remaining 47re trannys for SO trucks built through January or February 2003. My SO has a late March 2003 build date and the 48re.

 

[Matt400]

I owned an 03 CA SO 48RE and now an 05 48RE.

What I notice is an improvement in the shift strategy plus the 05's tow/haul works better than the 03's OD/off function.



Big difference in power too. The 05 stock is like the 03 with a VA pressure box turned all the way up. The 05 is more quiet.

My 03 2500 had the 10. 5 diff in the rear and the 05 has the 11. 5 in the same 2500 configuration.



My 03 used an electric vacuum pump, for the cruise I believe but never checked for sure. You could hear it cycle once in a while. The 05 does not have that.



The 03 had metal side tanks on the intercooler and my 05 has plastic.