I tell you, one of the things that'll make your heart skip a beat is having the transmission in your Chevy Express or GMC Savana start 'acting up', like in not changing gears smoothly or it starts slipping between gear changes. Depending on the cause of the shifting issue, you may end up with a smaller than expected repair bill or a hefty one.
In this guide, I'll answer some of the most common Chevy Express/GMC Savana automatic transmission questions like: 'How can I tell if the automatic transmission is bad? How do I figure out if it's just a bad shift solenoid? Or how can I tell if it needs a complete overhaul?'.
While I won't be walking you through a tear down and rebuild of your automatic transmission, the info I'll share with you will help you figure out whether the trouble with your van's automatic transmission stems from a faulty shift solenoid/sensor or if it's a more serious internal issue.
Contents of this tutorial:
- What Automatic Transmission Does My Chevy Express/GMC Savana Have?
- The Two Most Common Types Of Transmission Failure.
- How Can I Tell If It's Just A Solenoid Failure?
- How Can I Tell If It's An Internal Mechanical Issue Requiring A Complete Overhaul?
- Transmission With Both A Solenoid Failure And Internal Damage.
- More Chevy Express/GMC Savana Articles And Tutorials.
You can find this tutorial in Spanish here: ¿Cómo Me Doy Cuenta Si La Transmisión Está Fallando? (2003-2013 Chevy Express, GMC Savana) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- Chevrolet Express: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013.
- GMC Savana: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013.
What Automatic Transmission Does My Chevy Express/GMC Savana Have?
The 2003-2013 Chevy Express and GMC Savana passenger vans use one of two automatic transmissions. They either come equipped with a 4L60-E automatic transmission or a 4L80-E automatic transmission. Here are the specifics:
- 4L60-E: Installed in the light-duty 1500 and 2500 series vans (below 8,500 pounds GVWR). The 4L60-E is optimized for fuel economy and smooth driving over towing capacity.
- 4L80-E: Used in the heavy-duty 2500 and 3500 series vans (above 8,500 pounds GVWR). The 4L80-E is designed to perform in demanding conditions, including towing and carrying heavy payloads.
The easiest way to tell the difference between the 4L60-E and the 4L80-E is counting the amount of bolts used to bolt the fluid pan to the transmission and the fluid pan's shape (see illustration above):
- 4L60E: The fluid pan uses 16 bolts and is shaped like a 'square'.
- 4L80-E: The fluid pan uses 17 bolts and is shaped like a 'rectangle' with two corners shaved off.
The Two Most Common Types Of Transmission Failure
One of the things that will help you to troubleshoot your van's transmission problem (to a bad shift solenoid or an internal mechanical issue), is knowing that it'll usually fail in one of two ways:
- Transmission is 'slipping': 'Slipping' can be best described as having the transmission go into neutral (when it should be engaged in gear) when in drive (D). This causes the vehicle to not move or a delay in acceleration no matter how much you step on the accelerator pedal. This issue is caused be several problems:
- Low fluid level: The most common cause. A low level of transmission fluid is usually the result of a fluid leak from the transmission pan gasket or either the front or rear transmission seals.
- Internal mechanical failure:. The internal components of the transmission have failed, such as: clutch packs, transmission band, hard parts (such as drums), or metal gears.
- Transmission does not shift out of gear:
- This generally happens when the PCM senses an electrical problem and commands the transmission to stay in what is known as 'Limp In Mode'.
- In 'Limp In Mode', the automatic transmission will not down-shift or up-shift at all.
- The usual cause of this condition is a bad shift solenoid, although some internal mechanical problem/damage can also cause this.
Each one of the above conditions has a specific cause and in the next sections, we'll explore this a bit more in-depth.
How Can I Tell If It's Just A Solenoid Failure?
Both the 4L60-E and the 4L80-E are electronically controlled by the PCM and have several solenoids and sensors the PCM needs to control the up-shifts and down-shifts. If any one of these sensors/solenoids fail or the fuse(s) that supplies the solenoids gets blown, the transmission will go into 'Limp In Mode'.
What makes it pretty easy to tell if the automatic transmission failure is just a solenoid related issue is that the transmission doesn't 'slip'.
Here are some very specific symptoms you'll see when a transmission solenoid goes bad:
- The PCM is also gonna' light up the check engine light (CEL) and store a specific shift solenoid diagnostic trouble code. You'll see one or several of the following transmission diagnostic trouble codes:
- P0700: Transmission Control System Malfunction
- P0751: 1-2 Shift Solenoid Valve Performance
- P0753: 1-2 Shift Solenoid Valve Electrical
- P0756: 2-3 Shift Solenoid Valve Performance
- P0758: 2-3 Shift Solenoid Valve Electrical
- The speedometer does not work and you might have one of the following trouble codes:
- P0500: Vehicle Speed Sensor Malfunction
- P0501: Vehicle Speed Sensor Range/Performance
- P0502: Vehicle Speed Sensor Low Input
- P0503: Vehicle Speed Sensor Intermittent/Erratic/High
- Your 4L60-E/4L80-E automatic transmission will stay in only one gear no matter what the vehicle speed.
- As you accelerate your van, it feels very underpowered. This is due to the fact that the transmission is starting out in 2nd gear.
- At speeds over 35 MPH, the engine feels like it's over-revving. This is also due to the fact that the transmission is staying in 2nd gear and the gear ratio provided by 2nd gear is gonna' keep the engine working pretty hard at any speed above 35 MPH.
In conclusion, I want to emphasize that the three most important things that will tell you that you have a solenoid or internal transmission sensor problem are:
- You'll have a specific transmission diagnostic trouble code.
- The automatic transmission does not 'slip', no matter how many times you road test your vehicle.
- The 4L60-E/4L80-E stays in 'Limp In Mode' (note: see Transmission With Both A Solenoid Failure And Internal Damage).
I've written a tutorial on how to test the A and B shift solenoids on the 4L60-E automatic transmission (also known as the 1-2 or 2-3 shift solenoids) that may be of help and you can find it here:
In the next heading, we'll find out more about the specific symptoms of a 4L60-E or 4L80-E with internal mechanical damage.
How Can I Tell If It's An Internal Mechanical Issue Requiring A Complete Overhaul?
I believe that the clearest sign that the 4L60-E (or 4L80-E) transmission in your van has an internal mechanical failure (and which will require a complete overhaul to solve), is that it 'slips'. Your Chevy Express/GMC Savana may present one or more of the following symptoms:
- Usually (but not always), the PCM will set a 'gear ratio error' transmission diagnostic trouble code. Here are some more specifics:
- P0730: Incorrect Gear Ratio
- P0731: Gear 1 Incorrect Ratio
- P0732: Gear 2 Incorrect Ratio
- P0733: Gear 3 Incorrect Ratio
- P0734: Gear 4 Incorrect Ratio
- As you accelerate your vehicle, the transmission feels like it was thrown into neutral all of a sudden.
- No 1st gear, specifically, you put the transmission in drive but no matter how much you accelerate the engine, your vehicle does not move.
- The transmission shifts into 1st gear after you've come to a complete stop causing a very noticeable jolt (this jolt is more pronounced the faster you've been traveling and the quicker you come to a complete stop). The normal behavior is the transmission shifting into 1st gear before you come to a complete stop.
- No Reverse gear, although the transmission seems to work fine in Drive.
- When you remove the transmission fluid pan, you'll find sediment. This sediment is the friction material that has fallen off the friction discs (which are located inside the transmission).
- You may find metal shavings in the fluid pan mixed in with the sediment.
Removing the transmission fluid pan to see if you have metal shavings and/or friction material sediment on the pan is what will give you the definite proof that you have internal transmission damage (and in need of a transmission overhaul).
Transmission With Both A Solenoid Failure And Internal Damage
I want to let you know that it's possible for your 4L60-E or 4L80-E in your Chevy Express (GMC Savana) van to have a failed shift solenoid and internal transmission damage (at the same time).
The issue tends to arise specifically when there is internal damage to the components that handle 3rd or 4th gear. Initially, you won't notice this problem because the transmission doesn't shift into these higher gears, staying in 'Limp In Mode' instead. However, after you replace the bad shift solenoid or sensor, the transmission starts shifting to higher gears. It's at this point that you may experience the transmission slipping in 3rd or 4th gear.
I've seen this type of problem many times and I've found out that when I drop the transmission fluid pan (to test and replace the solenoid) and it's full of sediment and metal shavings, the likelihood of the transmission slipping in higher gears increases exponentially (since the sediment and metal shavings are a clear indicator of internal mechanical damage).
More Chevy Express/GMC Savana Articles And Tutorials
You can find a complete list of articles and diagnostic tutorials for the V8 Chevy Express and GMC Savana here:
Here's a sample of the tutorials you'll find in the index:
- How To Test For The Fuel Pump (2008-2013 V8 Chevy Express, GMC Savana).
- How To Test The CKP Sensor (2008-2013 Chevrolet Express, GMC Savana).
- How To Test For A Blown Head Gasket (2003-2013 V8 Chevy Express, GMC Savana).
- How To Diagnose An Engine Cranks But Does Not Start Problem (2003-2007 V8 Chevy Express, GMC Savana).
If this info saved the day, buy me a beer!
