[MrVang]

I have a 2011 Traverse with 129,000 miles, owned since new and never had a transmission problem. I feel I should change the trans fluid since the recommended change was at 100k. I drive mostly highway miles, and never towed anything. I've seen some threads on here (and you tube videos) to drain/replace/drive 2-3 times and check for the fluid color change. Others have said to have the dealer/shop perform a flush/fluid exchange. I would like to do the fluid drain/replace myself as it appears very simple. I like to do most DIY work on the vehicle. Thoughts on those who have done their own drain/replace or had it flushed by a professional. Did either lead to any other trans issues afterwards? Thanks.

I just did my own transmission drain and fill yesterday on my 2018 Traverse AWD with just 77,000 miles on it. Only difference is time and money. You save money doing it yourself manually at the cost of time to do 2 drain and refill to get all the okd fluids out completely. The other option is more expensive but quicker in one go using a machine to flush out every drop of the old fluid with a new fluid. And you never know what kind of fluid they're using that could spell more problems down the line using cheap fluid.

 

[MrVang]

the problem with the flush- is many places will use the machines that also put in some detergent.
Anything other than Dex VI is considered a contaminant by GM.


But- the detergent stuff- many times dislodges stuff that then gets stuck elsewhere, or opens up something that was being masked... and then the trans goes south.
Ive read post on other forums where the trans takes a dive after sometimes after a flush.


Since youve got 129,000----


What I would do, is do 1 drain/refill and drive for maybe 3000 miles.
Why?


The new trans fluid, may have cleaners/anti varnish stuff... etc.. that may begin to in a sense clean up the varnish deposits that have accumulated over 129,000....
if you clean up too much stuff.. will there be problems?


What I did, was start early with the drain/refills to keep it clean and varnish free.
So far so good at 142,000.

Yes the key to keeping that tranny running in tip top shape is an early drain and fill with fresh new fluid when it starts to turn black. Never tar black because that would be bad and if you change when it is at that tar black stage with a new fluid. You could ultimately set off a grenade and destroy the whole tranny with a new fluid that is much thinner and and less contaminants. Hence why some mechanic are hesitant to do a tranny flush on a vehicle with over 150,000 miles on it and the fluid has never been changed since it left the dealer lot. And why they just recommend you ride it till it goes kaboom because there's no point in saving it now when it is already way pass the point of safe to do a tranny flush without torpedoing the tranny down the line. All that gunk and black tar color is the only thing keeping that tranny lubricate and running without any major problem.

 

[MrVang]

I never let anyone else working on my vehicle. I just do it myself if problem arise after then I have no one else to blame but me since I was the one working on it. What are the chance of me screwing up? About 1%. My point is you never know what kind of mechanic you got, that is working on your vehicle and that's where things can go south later down the line. Best you start learning how to work on your own vehicle. And put those savings towards something else better. Here's a rule of thumb when buying a new or use vehicle."NEVER SETTLE FOR LESS THAN WHAT IT'S WORTH!" If it doesn't look right nor laid out in their proper place. Chances are the vehicle is a terrible car to invest in. Just walk away and keep searching.