What type of fluid for my GM 8L90 transmission?

Questions and Support
1

I’m looking for some advice and help with my GM 8L90 transmission, specifically found in my Chevrolet. I’ve heard a lot of different recommendations, and I want to make sure I use the right fluid for maintenance.

Some Key Points:

  • Transmission Background: The 8L90 is a popular 8-speed automatic transmission used in various Chevrolet models. Understanding the correct fluid is crucial since it affects performance and longevity.
  • Fluid Specifications: What exactly are the specifications I need to look for? Is there a specific type of fluid (Dexron, Mercon, etc.) recommended?
  • Brand Recommendations: Are there any brands that are particularly well-regarded for use with the 8L90? I’ve heard suggestions, but I’d love to get more opinions on what others have used.
  • Top Off or Full Change: If I’m just topping off the fluid, is there a different type or method than if I were to do a full change? What should I consider during the process?
  • Performance Optimization: Has anyone noticed any performance improvements after using a specific fluid? I’m curious if there’s a noticeable difference.
  • Common Issues: Any common problems related to fluid type that I should be aware of?

I’m keen to hear any personal experiences or tips you all might have, especially if you’ve encountered issues or had great success with this transmission. Thanks in advance for the help!

2

When it comes to the GM 8L90 transmission, GM recommends using their own Dexron VI fluid. It’s specially formulated for these transmissions, ensuring optimal performance.

2 Likes
3

I’ve also heard good things about some aftermarket fluids. Has anyone tried the Royal Purple Max ATF? Are there any downsides?

4

I’ve been using the AMSOIL Signature Series ATF in mine, and it’s been fantastic. Better shifting and performance overall. Just make sure it’s fully compatible with Dexron VI.

5

Honestly, I found it to be a bit pricey. While it may perform well, I prefer sticking with the OEM fluids for peace of mind.

3 Likes
6

Great to hear everyone’s experiences! I’m new to this. Is there a specific reason why some prefer OEM over aftermarket?

7

In my experience, it’s usually about reliability and manufacturer trust. OEM fluids are tested for compatibility and performance with the vehicle.

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8

What about the different draining and filling methods? Any tips on making the process smoother? I’ve read that it can be quite a hassle.

9

Definitely! Using a fluid transfer pump can save you a lot of mess. Plus, don’t forget to properly warm up the transmission before checking levels.

10

I just love how everyone’s advocating for their favorite fluids. It’s like a transmission oil showdown! Just don’t spill it in your driveway; it might ruin your weekend.

11

Haha, so true! Make sure to clean up properly because that stuff can stain. Also, is there a noticeable difference in performance between fluids?

12

I would recommend changing the transmission fluid for the GM 8L90 every 50,000 miles for optimal performance. It’s crucial for the longevity of the transmission.

13

That’s great advice! Regular fluid changes can significantly reduce wear and tear on the transmission components.

14

I’ve also heard that using the right fluid type is crucial. Always check your owner’s manual for the recommended fluid specification!

15

Exactly! Using Dexron VI is essential for the 8L90. It’s all about maintaining the proper viscosity.

16

I always check my fluid levels regularly—it’s easy to overlook. Keeping tabs helps catch any issues early!

17

It’s easy to forget about transmission fluid, but regular maintenance is key! It can save a lot of headaches later.

18

Totally agree! Plus, doing it yourself can be pretty satisfying.

19

My mechanic told me to also avoid heavy towing if possible—helps extend the transmission life!

20

That’s wise advice! Heavy loads can strain the transmission and lead to early failure.