How often do you change trans fluid?

[KB24]

Hey guys, how many km's until u change ur trans fluid?

Also, i changed my oil today for the first time after my warranty used to cover it, and when i cleared the oil indication back to 100%, it changed my trans fluid to 100% too.
did i do something wrong?

[o3cts]

they say its good untill 100k for normal driving , but i gewt my flush every 30k to be on the safe side, also because i push my car hard.

[KB24]

cool man thanks

[GT!]

I've never changed the tranny fluid in any of my cars, and have never had a problem. 90 Grand Prix STE (280,000 kms when sold, and still running fine) and a 99 Montana (256,000 kms and counting). Rest of my cars have had a manual tranny, which I didn't change either - 92 BMW 325 (287,000 kms when sold) and my current CTS with 113,000 kms.

-GT

[DDS rollin a CTS]

According to the computer, the trans fluid life on my 03 CTS is still at 100%, and its at 64K miles.

[z06bigbird]

Old service writer told me 30 years ago that I would be wise to change my tranny fluid every 25k miles. I do it myself. Very easy with jack stands and a hydraulic lift.

[mrplow2k69]

would you guys put fully synthetic in? i got the 3.6. oil that is!! heh

[suprane1]

100K miles appears to be the correct time to change the trans fluid. They are now putting Dexron VI (6) in the transmissions from the factory and it is mostly synthetic (supposedly above 90%).

Here’s what GM has to say about the new DEXRON VI:

Automatic transmission fluid (ATF) is considered the life-blood of the automatic transmission. It is used to transfer power in the torque converter and provide the pressure to apply the transmission’s various clutches and bands. It also is used to clean, lubricate and cool the components of the transmission. GM’s new transmission fluid, DEXRON®-VI, was developed to have a more consistent viscosity profile; a more consistent shift performance in extreme conditions; and less degradation over time.

Beginning with the design and development of GM’s new Hydra-Matic 6-speed rear-wheel-drive transmissions, GM Powertrain engineers determined the need for a new transmission fluid to withstand the complexity of the clutch-to-clutch transmission operation. Additionally, GM engineers identified opportunities to improve viscosity, durability, and impact on fuel economy with a new fluid.

"The development of DEXRON®-VI is the first time an automotive company has worked so closely with petroleum and additive companies to develop a new fluid," says Roy Fewkes, driveline fluids group leader, GM Powertrain. "The result is a new fluid that significantly outperforms existing fluids in every aspect. In fact, we have had to significantly extend the length of our durability tests to fully test the fluid’s capability."

Internal GM tests have demonstrated DEXRON®-VI to deliver more than twice the durability and stability in friction tests compared to existing fluids. It also has demonstrated superior performance in pitting, foaming, oxidation and shear stability tests.

Here’s what it means for ZZPerformance and your our transmissions:


We believe in delivering the best possible transmission in the world. This means keeping up on all the latest technologies and constantly striving to improve all of our product offerings. The new Dexron 6 transmission fluid allows us to deliver a transmission that lasts longer, performs better and at the same time gets better gas mileage. The viscosity of Dexron 6 drops from 36 to 30 on cold starts and a little when warmed up as well. All while delivering better shifting and better protection during hot operation.

Bottom line is longer clutch life, quicker shifts, improved fuel economy and more HP put to the ground.

[ltman49]

Is the trans fluid gauge correct? How does it determine how much life you have left?

[RobertCTS]

Originally Posted by ltman49

Is the trans fluid gauge correct? How does it determine how much life you have left?

By miles. Never had a car for 100,000 miles so I've never changed it. I also use the recommended synthetic oil for the engine.

[dup's Cadi]

I changed mine all over the raod last week when the tranny cooler part of the rad blew, and flooded my tranny with coolant. Now I have a nice B&M cooler mounted up front, right after I pumped 30 Liters of fluid through it to get all the coolant out. It was really fun.

[2004CTS]

Sounds like you inadvertantly changed the trans life to 100% by pressing the button at the wrong time, but not sure. I plan to change mine at 50K, but follow the guidance of your owner's manual and you should be fine.

[Paco.]

The manuel says you dont need to change the fluid unless you really push your car, in like hot city conditions, or use it for delivery, etc...