GMC Sierra Transmission Fluid

Black GMC Sierra Pickup Truck - Transmission Cooler Guide

What Type of Fluid Does a GMC Sierra Use?

Depending on the transmission the comes in your GMC Sierra, the transmission fluid is pretty consistent. Since the GMC Sierra has a 4l60e, 4l80e, 6l80, or 8l90 transmission, it will take either Dexron 3 or Dexron 6

However, if you have a Duramax powered Sierra, it will come equipped with an Allison 1000 transmission, which uses TranSynd transmission fluid.

The great thing about  Dexron transmission fluid is that you can use Dex VI in older GM transmissions that call for Dex III. 

These transmission fluids are common in most GM vehicles. 

GMC Sierra Transmission Fluid Capacity

The fluid capacity of your GMC Sierra depends on what automatic transmission you have. In most cases, your GMC Sierra’s transmission fluid capacity is anywhere from 10-14 quarts. 

Here are the capacities by transmission that come in a GMC Sierra:

  • 4l60e: 11.5 quarts
  • 4l80e: 14 quarts
  • 6l80e: 11-13 quarts
  • 8l90: 11.5 quarts

How To Check GMC Sierra Transmission Fluid

Checking transmission fluid in a GMC Sierra is simple and quick to do. It’s always recommended that you check transmission fluid when the vehicle is on and in park on a flat surface.

transmission fluid on dipstick showing correct levels

How To Add Transmission Fluid To GMC Sierra

Adding transmission fluid to your GMC Sierra is a done by filling transmission fluid through the transmission dipstick tube, which is located on the passenger side near the firewall.  

When adding transmission fluid to your GMC Sierra, it is important to make sure you have the correct level, as mentioned before. 

GMC Sierra Transmission Fluid Change

The beauty of the GMC Sierra like most GM vehicles is that it is easy to maintain, making them great vehicles for the average DIYer.  The GMC Sierra was designed for ease of use, making transmission fluid changes an easy task for the average weekend mechanic. 

This video below shows step by step how to change the transmission fluid on your GMC Sierra.

How Often Should You Change Transmission Fluid In A GMC Sierra?

The common automatic transmission fluid change interval for the GMC Sierra is every 30,000-60,000 miles depending on condition of the fluid.  

For “severe” use such as towing often, hauling heavy weight, or sitting in stop and go traffic, it’s better to change the fluid every 30-45,000 miles. 

The best indicator to determine how often to change transmission fluid in your GMC Sierra is by looking at the transmission fluid every so often to see what condition it’s in. In the fluid color chart below you will see how transmission fluid gets darker over time die to wear and overheating. 

Transmission Fluid Color Comparison chart


GMC Sierra Transmission Fluid Temperature 

The ideal transmission temperature for your GMC Sierra when fully warm is in the 150 – 180 degree range. This is a safe transmission temperature that will allow for tens of thousands of miles of fluid life.  

The transmission temperature chart below shows how long you can expect your GMC Sierra’s transmission to last at a given temperature.

Transmission Fluid Temperature Chart

Get A Transmission Cooler For Your GMC Sierra

Looking to lower the transmission fluid in your GMC Sierra? Install a transmission cooler! Our helpful transmission cooler buyer’s guide gives you all the information you need to install a transmission cooler and find the right one for your needs.

In our recommendation, a medium sized plate and fin or stacked plate style cooler would be best for your GMC Sierra to keep transmission temperatures down.

Looking For More GMC Sierra Transmission Cooler Options?

Black GMC Sierra Pickup Truck - Transmission Cooler GuideView our GMC Sierra transmission cooler guide

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