Skip to Content

Chevy Avalanche Transmissions: Overview, Problems, Fluids

On this blog, we’ve already done extensive research on several Chevrolets and their transmissions. Today, we will talk about the two generations of the Chevy Avalanche and give you an overview of what transmissions are actually used in this vehicle. First, a quick answer:

The 2002 – 2006 Chevy Avalanche has a 4-speed 4L60-E automatic transmission and a 4-speed 4L80-e automatic transmission. The 2007 – 2013 Avalanche also has a 4L60-E automatic and a newly developed 6-speed 6L80 automatic transmission.

However, that doesn’t tell the whole story. Below we first outline all the generations of the Avalanche and explain which transmissions have been used with each generation. After that, we’ll talk about how long these transmissions last and the cost of replacing them. Finally, we’ll look into the common problems of each type of transmission. Read on!

What Transmissions Has The Chevy Avalanche Used?

First Generation (2002 – 2006)

  • 4-speed 4L60-E automatic
  • 4-speed 4L80-E automatic

Second Generation (2007 – 2013)

  • 4-speed 4L60-E automatic
  • 6-speed 6L80 automatic

How Long Does A Chevy Avalanche Transmission Last?

Chevy Avalanches are known to be fairly reliable trucks, although they do certainly have their defects. According to repairpal.com, Chevy Avalanches end up at the garage for an unexpected visit about 0.46 times per year. In that case, there’s an 18% chance the problem you’re running into is severe.

However, most of these problems don’t seem to have any effect on the transmission. We’ll dive into specific transmission problems shortly, but they don’t seem to be the thing that would trouble the Avalanche.

Chevrolet advises you to service the transmission every 45,000 miles. However, consumer experiences tell us that doing this every 30,000 miles isn’t a bad idea if you want to keep the transmission in the best condition possible. If you do so, you can expect the transmission to last at least 200,000 miles, with a maximum of 300,000 miles depending on the conditions.

Also, read Chevy Colorado Transmissions.

How Much Does A Chevy Avalanche Transmission Cost?

If you’re looking to replace the transmission of your Avalanche, then you’re most likely also interested in knowing how much your particular transmission costs. Below we’ve outlined the specific transmissions that are used in the production span of the Avalanche, and we’ve attached prices that we found with online retailers:

  • 4-speed 4L60-E automatic: $1,795
  • 4-speed 4L80-E automatic: $2,031
  • 6-speed 6L80 automatic: $3,899

Also read: Chevy 1500 Transmissions & Chevy 2500/3500 Transmissions

Common Chevy Avalanche Transmission Problems

Chevy Avalanche’s and their transmissions normally have few problems. However, there are some elements you should look out for. Below we’ve outlined the most common ones.

4L60-E

The 4L60-E is a transmission that’s good or bad, depending on the vehicle that you own. If you happen to have a Silverado 1500 with a bad transmission, then you can expect the following symptoms:

  • Problems with shifting into 3rd gear whereas the car acts like it’s in neutral. The problem here is 3/4th gear clutch pack failure. You’ll need new pistons and a clutch pack to replace this.
  • You lost your second or reverse gear. In this case we’re talking about a broken drive shell which will need to be replaced.
  • Problems with shifting into 2nd gear with a possible ‘check-engine’ light. Problem here is a worn TCC regulator valve that causes the converter clutch to slip.

4L80-E

The 4L80-E is not a transmission with many problems. However, there are some things that you should look out for:

  • Irregular shifting: sometimes a throttle position sensor or input/output speed sensor fails on the transmission which causes it to develop erratic shifting.
  • Overheating: overheating is another symptom that can sometimes occur (especially when towing heavy loads). The only thing you can do here is make sure that there’s enough transmission fluid in the transmission. Otherwise, damage may occur to the clutches, seals and valve body.

6L80

The 6L80 is another transmission that does have a small list of well-documented problems. These include:

  • Vehicle not moving into, not releasing or popping out of the park position.
  • Loud rattling noise in reverse
  • Transmission not engaging after changing the transmission fluid and filter.
  • Moisture gets trapped on the spline which destroys the trans output shaft and transfer case 4-wheel drive unit splines.

Most of these problems are caused by a rod actuator which is known to fail. The last problem is caused by failing O-rings which need to be replaced.

Also, read Chevy Tahoe Transmissions: Overview, Problems, Fluids.

Differences Between Transmissions

Now that you know what kind of problems the transmissions have, it’s also important to consider the main differences (and which one is therefore considered better or worse). Let’s start with the difference between the 4L60-E and the 4L80-E.

The difference between the 4L60-E and the 4L80-E is that the 4L80-E is designed to carry heavier loads and, therefore, larger. The 4L60-E has a weight of 190 pounds with fluids, and a length of 23.5 inches, whereas the 4L80 is 236 pounds with fluids and has 26.4 inches. The 4L60-E can carry a Gross Vehicle Weight of 6,000 pounds, whereas the 4L80-E can carry a GVW of 8,000 pounds.

The 4L80-E and the 6L80 have some differences. The first difference is that the 4L80-E has a Gross Vehicle Weight of 8,000 pounds, whereas the 6L80 maxes out at 8,600 pounds. Another difference is that the 4L80-E is a 4-speed, and the 6L80 is a 6-speed. The 6L80 is also considered to be sturdier than the 4L80-E.

Also read: What Transmission Is In A Chevy Trailblazer?

Transmission Fluids And The Chevy Avalanche

Suppose you want to make sure that the transmission of your Avalanche lasts as long as it can last, then you’ll need to take care of it. As a general rule of thumb, Chevrolet advises you to change the transmission fluid of your Avalanche every 45,000 miles. However, what type of transmission fluid you should use depends on the transmission that you have. Below we’ve created an overview of the TF’s that are recommended for each transmission:

Sources