servicing a 2018 GM 6speed transmission

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I just bought a new to me 2018 Cadillac XTS with 3.6 and 6-speed transmission. Most say you can only drain around 3 Qts from the plug. I really haven't checked it out so looking for advice on preventive maintenance. present mileage is 29,000.
 
Same setup as the Impala and may other FWD 3.6/6-speed vehicles. I was able to get about 4 last time I did one.
I would do a drain/fill every 30-35k on those. I used Maxlife and it works well, that and only $18 gallon at walmart.
 
Wife's 6-speed Equinox and my former Traverse would give up about 3.5 quarts. Wife's car doesn't have the dipstick and just the fill plug on the side. You'll need to have the engine running to fill it properly, you'll only get about 2 quarts in before it overflows if you don't.
 
That 3 quarts will be enough.

Do a drain and fill every 60k or so and you will be fine. Of course, you can always do it more often if you wish since the drain plug makes it so easy
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Mine has a 6 speed 6L90. I was able to pull only 3-1/2 quarts out through the fill tube with a vacuum-based transfer pump. Surprisingly, the transmission only holds 6-1/2 quarts according to the owners manual.
 
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Is this the 6-speed front wheel drive transmission (6Txx)? My Fords have the 6F55 (which is probably GM's GT80) and the drain plug drops out 4-4.5 quarts of Mercon LV / Dexron VI. This is the largest version of the joint-venture transaxle though.
 
Originally Posted by metroplex
Is this the 6-speed front wheel drive transmission (6Txx)? My Fords have the 6F55 (which is probably GM's GT80) and the drain plug drops out 4-4.5 quarts of Mercon LV / Dexron VI. This is the largest version of the joint-venture transaxle though.


I have the smaller 6F35 in our Explorer which I believe was also part of the joint GM-Ford joint venture design. Every time I do a drain and fill it's 4 quarts out always. But I do it cold after it sat over night. It's ridiculously easy to do cold drain and fills with this transmission as there is no pan, just a drain plug in the bottom of the casing. I fill it through the vent tube in the engine bay with the 4 quarts cold. The transmission hold 9 quarts total according to the owners manual.

Whimsey
 
Thanks to all, like most of us I will probably service early, and often. We do love our lube.
 
Originally Posted by gotnogunk
Thanks to all, like most of us I will probably service early, and often. We do love our lube.



After you get the break in oils out there is no need to do frequent changes DEXRON VI is a very good fluid.
 
If you have AWD don't forget to service the transfer case. Fluid change on that is really simple also and regular fluid changes there will keep it alive for a very long time. I service my 16 NOX 3.6 buy the severe Duty maintenance schedule as I like to run my vehicles to at least 200k
 
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