2017 CT6 Transmission Fluid Change Interval?

ClearTheCode admin answer:

It's great you're being proactive about your 2017 Cadillac CT6 Platinum's transmission fluid. While GM often refers to transmission fluid as "lifetime fill," many automotive experts and experienced owners recommend a fluid change between 60,000 and 100,000 miles, especially for vehicles driven in demanding conditions (towing, heavy city traffic, extreme temperatures). Given your 75,000 miles, it's a good time to consider it.

Causes for proactive maintenance:

1. Fluid Degradation: Over time and mileage, transmission fluid breaks down, losing its lubricating and cooling properties.
2. Contaminants: Wear particles from clutches and gears can accumulate, potentially causing damage.

Recommended Steps:

1. Fluid Type: Your CT6 requires Dexron VI automatic transmission fluid. Using any other type can cause serious transmission damage.
2. Drain and Fill vs. Flush: For high-mileage transmissions without prior service, a simple "drain and fill" is often recommended over a full "flush." A flush can sometimes dislodge debris that then causes problems in older transmissions. A drain and fill replaces a significant portion of the old fluid without the higher pressure of a flush.
3. DIY Difficulty: A drain and fill can be a DIY project for those with mechanical experience, requiring proper jacking, a torque wrench, and a method for accurate fluid level checking (often involving specific temperature ranges and procedures). However, the precise fluid level check can be tricky.

When to see a shop:

• If you're unsure about the process or fluid level checking procedures.
• If you've noticed any unusual shifting, slipping, or harsh engagement, as these could indicate existing transmission issues that require professional diagnosis before any fluid service.