What transmission does a 2004 Silverado 1500 have?

The 2004 Chevrolet Silverado 1500 was equipped with one of two transmission options: a 4-speed automatic or a 5-speed manual. The specific transmission in a 2004 Silverado 1500 depended on the engine and trim level selected by the original owner.

4-Speed Automatic Transmission

The most common transmission found in the 2004 Silverado 1500 was the 4L60-E 4-speed automatic. This transmission was paired with the standard 4.8L and 5.3L V8 engines. The 4L60-E was a reliable and durable transmission that provided smooth shifting and good fuel economy. It was the default transmission choice for most 2004 Silverado 1500 models.

5-Speed Manual Transmission

A 5-speed manual transmission was also available as an option on the 2004 Silverado 1500, typically paired with the 4.3L V6 engine. This transmission, known as the Getrag 260, offered more control and engagement for drivers who preferred a manual gearbox. However, the 5-speed manual was less common than the 4-speed automatic in 2004 Silverado 1500 models.

Transmission Selection

The transmission in a 2004 Silverado 1500 was determined by the engine and trim level selected by the original owner. The 4L60-E 4-speed automatic was the more popular and widely available option, while the 5-speed manual was a less common choice. Factors such as driving preferences, towing needs, and fuel economy considerations would have influenced the transmission selection for each individual 2004 Silverado 1500.

What transmission is in a 2004 Silverado 1500?

4L60E Trans & Conv, Fits 2004 Chevrolet Silverado 1500, 4.8L Eng, 2WD or 4X4 GM.

How do I know what transmission I have in my Silverado 1500?

You can tell what transmission you have by checking the RPO codes on the sticker in the glove box or on the driver's side door jamb, or by decoding your VIN. You can also identify it by its physical characteristics, like the shape of the transmission pan or a transmission tag or sticker located on the case itself, which may be visible when looking under the truck. 
By using RPO codes

• Find the sticker: Look for a white sticker with a list of codes in the glove box or on the driver's side door jamb. 
• Locate the transmission code: Find a 3-character code that starts with "M" (for automatic) and cross-reference it with a lookup table or your owner's manual to identify the transmission model. For example, an M5X or M7S might correspond to a specific transmission. 
• Scan a QR code: Some newer models have a QR code on the driver's side pillar that you can scan with a smartphone app to see your vehicle's factory options, including the transmission. 

By using the VIN

• Locate your VIN: The Vehicle Identification Number is usually found on the driver's side dashboard or on the door jamb. 
• Decode the VIN: Use an online VIN decoder to get detailed information about your truck's specifications, including the transmission. 

By physical identification

• Look at the transmission pan: The shape of the transmission pan is often unique to the model. Check the number of bolts around the pan for confirmation. 
• Find the transmission tag: Look for a sticker or metal tag with a serial number or code stamped on the transmission case itself. 
• Examine the location of parts: For some models, like the 6L80, the electrical connector is located at the rear of the transmission, and the cooler lines have a specific pattern, which can help identify it. 

By using manual shifting (for a quick check of speed) 

• Engage manual shift mode: Put the transmission in manual mode and use the "+" button. Count how many gears the transmission can shift into to determine if it's a 6-speed or 8-speed, for example.
• Drive and count: While driving, shift into manual mode and count the available gears as you accelerate. This can give you a general idea of the transmission type. 

What year are 4L60E transmissions compatible?

The interchangeability of a 4L60E depends on its generation, which roughly falls into three groups: 1993-1997, 1997-2008, and 2009-present. The 1993-1997 models have a one-piece case, while 1997-2008 models have a two-piece case, and 2009+ models feature an internal mode switch, making 2009 and newer transmissions incompatible with earlier models. Within these groups, electronic and physical differences like the torque converter, input shaft, and wiring require specific consideration for direct swaps, though some adaptations are possible between certain years. 
Generation 1: 1993-1997 

• Key features: One-piece case, 4-bolt rear extension housing, shallow pan. 
• Interchangeability: Generally compatible with each other, but with some differences. 
  • 1993-1994: Use a simple on/off TCC solenoid. 
  • 1995 and later: Use a PWM (Pulse Width Modulation) solenoid for gradual lock-up control. 
• Note: 1995 is sometimes considered a "stand-alone" year due to specific valve body and solenoid changes. 

Generation 2: 1997-2008 

• Key features: Two-piece case with an 8-bolt bell housing, deeper pan, and a stronger 6-bolt rear extension housing. 
• Interchangeability:
  • 1997: Introduced a larger 300mm input shaft and torque converter for LS engine compatibility in Corvettes and F-bodies. 
  • 1999-2008: Generally interchangeable, but be mindful of specific electronics and cooler line positions. 
  • Note: Cooler line fittings may be in slightly different positions on later models, requiring minor bending of the lines. 

Generation 3: 2009-Present

• Key features: Internal mode switch that combines the function of the manual lever position sensor and pressure switch manifold, requiring different wiring and control components.
• Interchangeability: Not interchangeable with the 1993-2008 models, even with modifications. 

Important considerations for swaps

• Engine compatibility: Newer transmissions may have different input shaft lengths and torque converter sizes to match LS-based engines. 
• Electronics: The Transmission Control Module (TCM) needs to be compatible with the transmission's electronics. 
• Case and bell housing: The case and bell housing design changed from one-piece to two-piece between 1997 and 1999. 
• Wiring: Pinouts and connector types can vary between years, so check the harness and color before swapping. 
• Flex plate: The flex plate on the engine and the torque converter on the transmission must have matching bolt patterns and center pilot diameters. 
• Adaptation: Some adaptations are possible between certain years, but direct swaps are the easiest and most reliable. 

How do I tell if I have a 4L60 or 6L80?

You can tell the difference between a 4L60 and a 6L80 by checking the vehicle's RPO code, looking at the number of gears on the shifter, or examining the physical appearance of the transmission, particularly the pan and electrical connectors. The 4L60 is a four-speed, while the 6L80 is a six-speed, a key distinction you can see on the shifter. 
This video explains how to identify your transmission based on the gear shifter: 1mCodemans autoYouTube · Nov 2, 2023
Methods to identify your transmission
1. Check the RPO code

• Locate the RPO code: Find the sticker in your vehicle's glove compartment or under the hood. 
• Find the code: The 4L60 is typically associated with the M30 code, while the 6L80 has the MYC code, this Reddit post notes. 

2. Check the shifter

• Look at the gear selector: The 4L60 shifter will go from P, R, N, D, and then D321 (or similar), indicating a 4-speed. The 6L80 shifter will have a plus (+) and minus (-) symbol for shifting into higher gears, as it has a 6-speed, says this YouTube video. 
• Count the gears: Manually shift from a stop and count how many times the transmission shifts before it is in its highest gear. It will shift four times for a 4L60 and six times for a 6L80, explains this YouTube video. 

You can watch this video to learn how to count the gears on your shifter: 53sJR GunnYouTube · Oct 16, 2022
3. Inspect the transmission physically

• Examine the pan: The 4L60 has a rectangular pan, while the 6L80's pan is often described as more rounded or oval-shaped, say users on Facebook. 
• Look at the electrical connector: The 6L80's electrical connector is on the rear passenger side of the transmission, it points toward the rear of the vehicle and has a spiral groove where it twists and locks, notes this YouTube video. The 4L60's connector is different and often located on the side of the transmission, says this Facebook post. 

This video shows how to inspect the transmission for identification purposes: 1mPSI ConversionYouTube · Dec 8, 2020