When servicing 8T45/50/60, 9T45/50/60/65 and 6T30/35/40/45 transmissions on 2016-2025 Malibu; 2017-2026 XT5; 2018-2026 Enclave; 2019-2026 Blazer; 2020-2022 Encore; 2020-2025 XT6; 2020-2026 Encore GX, Envista, Equinox, Trax, Acadia; 2021-2026 Envision, Trailblazer; 2024-2025 XT4; and 2024-2026 Traverse and Terrain models, the automatic transmission fluid may have a difference in appearance and color. The fluid in some transmissions may have a very dark appearance, almost as if the fluid has been overheated or the transmission clutches are distressed.
The automatic transmission fluid in these transmissions may be red, brown, or black. (Fig. 11) It often will be darker as mileage increases. The fluid in these transmissions also tends to turn darker due to rust inhibitors used on internal transmission parts during assembly.
Fig. 11
If transmission fluid appears dark, do not assume that the transmission has internal damage, and continue with diagnosis of the concern. The transmission as well as the transmission fluid should not be replaced based only on the appearance of the transmission fluid.
During diagnosis, check the appearance of the fluid and for excessive metal particles or other debris:
- A small amount of friction material is a normal condition.
- A small amount of metal from the manufacturing process is a normal condition, which may be observed as fine silver streaks floating in the fluid.
- Large pieces and/or metal pieces in the fluid, or fluid that feels gritty when rubbed between your fingers, may indicate internal hardware damage and requires that the transmission be removed from the vehicle for further diagnosis.
- Cloudy or milky fluid or fluid that appears to be contaminated with water may indicate engine coolant or water contamination. Refer to Bulletin #08-07-30-035 for testing and more information.
- Fluid that smells burnt may be an indication of a possible failure within the transmission. Confirm any internal damage with a further teardown of the transmission.
TIP: Refer to vehicle’s Owner’s Manual for Severe Usage descriptions and advise customers accordingly about proper transmission fluid replacement.
Refer to Bulletin #25-NA-267 for additional information.
– Thanks to Matt Razz
