To double drain and fill or not?

[MurkyAsparagus]

Recently bought a ‘23 Chevrolet Blazer w/ 9T60. It’s coming up on 30k miles, where I intend on servicing the transmissions.

No external filter, just a small internal one. So, I will be doing just a drain and fill. With being low miles, should I do a single drain and fill or a double. I will be switching to a full synthetic Dexron VI rather than OEM Blend. For the next services, should I continue with only single drain and fills after getting all the break in fluid out?

 

[JavierH19]

With just 30k one spill is fine. I'd only do two or more on something that has dark fluid. I'd do a single spill and fill afterwards. I've never done two on any vehicle I bought and maintained since new just used ones with dark red fluid.

 

[MurkyAsparagus]

With just 30k one spill is fine. I'd only do two or more on something that has dark fluid. I'd do a single spill and fill afterwards. I've never done two on any vehicle I bought and maintained since new just used ones with dark red fluid.

I was thinking the same thing, thanks!

 

[BHopkins]

A single drain and fill will be fine, particularly if you plan on staying on a 30k service interval for the transmission. You are doing better than most on servicing a transmission, with 60k service being quite common, and even without regular services, GM transmissions tend to last a long time on the original factory fill.

 

[SevenBizzos]

At 30k ATFDFI, once is enough.

 

[barkingspider]

Drain and fill is plenty good

 

[charbaby]

It’s good to see that you’re doing the drain & fill at ~30K miles; way to go!
To me, 30K is not early as some techs/dealers may think, it’s on time IMO.
And every ~30K from here on. I typically want to change the filter(s) on the 3rd spill & fill.
Keep up the good work.

 

[JeffKeryk]

Some say the 1st service is important as it removes break-in materials. I would just do a single spill-and-fill.

 

[RobbS]

I was raised with the general rule to use OEM for transmission fluid and use AMSOIL for all differentials. Back when I had Cobra and Coupe SN95. AMSOIL differential fluid and FRRP additive fluid. That's what we ran . .410 & 3.73 I believe.

 

[slacktide_bitog]

One drain and fill every 30k is sufficient, especially if you're doing it from the first 30k.

If you do more than one drain, drive it a little between drains, anywhere from around the block to 5k.

 

[D1dad]

I’d see how the fluid drains. I do doubles if the 1st is dark enough to justify. Anything after the 1st is only replacing about 25% more but still. It’s piece of mind.

 

[dubber09]

Does the AT have cooler and easily accessible cooler lines? Asking as an option to replace entire ATF volume with fresh fluid is also valid.
That's what I did on my Kias. I replaced full ATF volume on Sportage at 20k miles and full volume on Forte at 30k miles; after that I do drain and fills every 30k miles and ATF comes out very clean and only darker than new. I did switch to MaxLife Multi Vehicle ATF right off the bat and keep using same ATF. AT filters are also non-serviceable in the Kias so I wanted to remove as much suspended abrasive material as I could to begin with.

 

[JackWildfeuer]

Good for you! You should alsways drain and refill transmissions, transfer gear case and differentials after 10,000 miles of breakin. If you think engines break in than you should never ever do a used oil analysis on transmission and differentials since they shed wear metals easily 10,000X more than an engine during break in and the particals are huge compared to an engine!

To be honest since GM and Ford have so many transmission issues I would use the same Fluid they put in the Corvette for the transmission and a lot of the problem child 8 and 10 speeds. I would use Mobil 1 Synthetic LV HP ATF.

 

[zogg]

I’m switching to the Mobil 1 hp dexron. As such, I’ll do two drain and fills to get as much dexron vi out as possible. Some folks do three when switching types of fluid.

 

[CleanSump]

All Dexron VI is synthetic. Too bad most torque converters don't have drain plugs anymore. It makes it easy to do everything but what's in the cooler with one simple drain when the TC has a plug.

 

[4wd]

The FWD transmission don’t drain allot - I’d measure and fill. Then with some great weather do it again 6-12 months later …
FWD’s can be tough on fluid - so physical appearance matters regardless of what’s said about motor oil …

 

[zogg]

Based on an updated TSB from GM, I opted to change the atf in my 2023 traverse 9 speed to the Mobil 1 hd Dexos , eliminating the Dexos vi. I opted to do 3 drain and fill events, driving 10 miles between each one. The tech at a local Chevy dealer said that would replace 90-95% of the Dex vi. They couldn’t do the flush because their machine was down. He said its $400 to do the flush. I paid $115 at Napa since the fluid is on sale during May. My wife said I owe her a night out with the $300 I saved….of course!

 

[burbguy82]

I would drain and fill & change the filter. It is your first change, and the filter will likely be the dirtiest at this first interval.

 

[JTK]

I would drain and fill & change the filter. It is your first change, and the filter will likely be the dirtiest at this first interval.

No pan or serviceable filter on these GM FWD based transaxles. Drains and fills on them are as easy as an engine oil change though.

 

[burbguy82]

No pan or serviceable filter on these GM FWD based transaxles. Drains and fills on them are as easy as an engine oil change though.

well then all you can do is keep fluid fresh then