Cobalt transmision fluid change

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My friend ask me to change the transmission fluid in his 2008 cobalt, but i cut not find the drain plug , I did some research and it has not drain plug because is a seal unit , I guess I have to drop the transmission pan and make a really big mess ? any other solution ? the car has only 500000 miles
 
there's always the cooler line flush method. I'm sure allot of instruction on this could be found on google. This will replace nearly all the fluid

another option would be vacuum suction out the dipstick tube. This will replace about the same amount of fluid as if there was a drain plug in the pan.

Really, either way will work. It's about how much you wanna spend, and how much fluid you want to replace. Having the suction option makes it easy to do a pan drain and fill while doing an oil change or when ever you have spare time.

Of course, you could just drop the pan it self. Only thing I would advise is have allot of newspaper on the ground if you choose to do this
 
just to be sure , there is not a drain plug in the transmidsion the car ? or maybe i am not looking in the right place
the car has only 50000 miles , should change fluid and filter or wait for more miles ?
 
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There is no drain plug or dipstick, but there is a fluid level check plug. You have to drop the pan and there's a filter inside. The pan gasket is reusable.

The transmission should be filled with Dexron VI and probably doesn't really need a fluid change. Unless you use Dexron VI it wouldn't even be worth changing. You can take off a cooler line and pump some of the fluid out to cut down on the mess when you remove the pan.
 
When I did a pan drop and filter change on the Malibu, I replaced the pan with DORMAN Part # 265809 from Rockauto. Comes with drain plug built in. I figured why not as I was already going to be making a mess anyway.

The fluid level check procedure is a pain in the rear though if you follow what is recommended. With a pan drop and filter change, I used a little less than 8 qts.

I'm of the belief that a fluid change at 50K is not a bad thing. I'm skeptical of the 100K mile claim.
 
There is no dipstick or drain plug on these transmissions. I changed it in my wife's Cobalt and also replaced the filter.

The filler is on the top of the transmission. It's a big plastic screwable plug. If I recall, it should take about 7 quarts to refill it assuming you let it all drain out. That number is in your manual though.
 
Here's a moc-up I did of a 4T45E some years ago showing the approximate level check and fill port locations..

That level check plug is facing the front right wheel, right at the top of the ATF pan flange. It's small.

You'd probably leave two quarts in the pan by draining from the level check plug alone.

The filter is under the pan like a conventional automatic.


074T45MN5LoR-1.jpg


Joel
 
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Originally Posted By: FFeng7
How much fluid comes out if you drain it through the check plug?


I'm not sure but I'd not enough to amount to much of a change. None to speak of would drain out with the engine running since that is how the level is checked, but some would come out if the engine was off. As mentioned about 7 qts comes out of the drain pan and up to about 12 qts with a cooler line flush. There's a lot of ATF in this transmission.

Pbm, JTK posted a good pic showing the fill plug.
 
Yeah I just did the pan drop on my cobalt. It was actually easy. It took right at seven quarts. I was just thinking I could drain some more out of the check level plug maybe halfway through the pan drop interval which I think I may do every 50000. I wish I would have gotten the transmission pan with a drain plug in it. I know the sell the one you can add to your current pan at advance auto parts. I've actually used one in the past but I hate to drill a hole in the current transmission pan.
 
In most of these GM 4 speeds, you do indeed have to remove the pan. You loosen a few screws on one side of the pan, and begin to remove them slowly to begin the drain on a small section. It is best to remove them on the side of the most gravity if you have a large drain pan. You can begin to remove them around the pan to allow you to drop it even more in the draining side. If you do it right, you won't splash any atf. Clean the pan and remove steel shavings and any sludge material. The magnet should be cleaned and placed back where to found it, which is generally marked in the OEM pans. Filter and O ring should be replaced. You can gently tap the old O ring inward with a flat screwdriver and mallet. But don't damage the transmission. When the O ring is bent inward a bit, it is easily removed with pliers.

Many of the pan gaskets with metal rings in the screw holes are allegedly reusable, but I like to replace them anyway. Get an OEM style gasket. Don't use the cheap rubber things (and never use cork!) or you will have to overtorque to keep it from leaking and might damage the pan around the screw holes. You can find a few inexpensive OEM style filter and gasket kits on Amazon for around $25, which is the same price that auto parts stores will charge for one with an inferior rubber gasket. The gasket needs no adhesives, and I believe that the pan is torqued to about 8-9 ft lbs when wet.

I generally replace the filter and refill in my GM cars with these transmissions every 40 to 60k.

It is very important not to overfill. In these 4 speeds I add 3.5 or 4 quarts before starting the engine. Let it warm to operating temp for 5 minutes and add more fluid with the check plug removed. You should cycle throgh gears a few times in the process. If ATF begins to drip out of the check plug, it has been ovefilled. Let the dripping cease before plugging it back up. ATF should only be filled on a level surface.
 
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