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3.6L 6 speed trans flush advice please

46181 Views 71 Replies 23 Participants Last post by  SilverSport
09 malibu 3.6L 6 speed with 50,000 miles on it. I was reading the owners maual and from what I understand the fluid is "lifetime" unless you fall under the severe duty catagory and then you need to change it at 50,000, is this correct?

I don't think I fall into the severe duty but I think I would like to change the fluid as a preventative maintenance thing, don't think it can hurt can it?

So if I do this do I need to flush it or can I drop the pan and drain and add new fluid? Also is there a servicable filter I need to change?

Any advice with this would be much appreciated,
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"But: transmission fluid flushes? Uh uh. Flushes have been known to break crap loose that eventually clog a fluid filter, and fry the tranny."

I disagree with your comment. A tranny should not have any crap in it. If there is, it is already to late for the tranny. Most people follow mfg. suggested intervals for tranny maintenance which is mostly too late IMO. You need to check your oil often to see any discoloration and smell. If it si dark and smell gas, it is time to change it regardless of your mileage. I find Chevy's 50K interval too late. I believe this should be 30K.

I also have 05 Ford Escape, which is the easiest vehicle to work on it and I do my own flushes. I ve 85K on it and I've done 3 flushes so far.
I agree with this. Here in Indiana when I check fluid on almost every vehicle at 50K it is brown and should have been changed a while ago. 30K is a good interval for almost anywhere. It won't hurt to do it early anyways.

The 6 speed for the 6 cyl and same for the 4 cylinder does not have a trans pan to drop for changing fluid. There is a drain plug on the bottom and a fill hole on the top, in your case with a dipstick. According to GM a drain and fill will require 5 quarts of fluid to fill it up afterwords. Total fill is 9.6 quarts, so it changes a decent amount of it.

This is where a flush has it benefits. Where I work we flush 14 quarts of trans fluid after running the flush chemical through the trans. The main benefit I like of the flush is it gets to the fluid that will contaminate the new fluid in just a drain and fill. Also, it gets to the fluid in the torque converter. I have flushed trans fluid when it was very dark with no negative effects later down the road.
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From what I understand of the owners manual reading the maintenance schedual chevy only recomends a 50,000 interval if you fall under the severe duty catagory. Otherwise they don't have any recomendation of tranny service, lifetime fluid. I thought I was doing good wanting to do something at 50K.

Well I'm around 50,000 and I would like to do some kind of maintenance, either a fluid drain and fill or a flush. I will check the color of the fluid tomorrow to see how it looks.

So there is no filter that needs to be replaced? I see one listed at parts stores. Can I flush the tranny at home by unhooking a cooling line? Or is a drain and fill good enough?

Thanks for the advice guys.
There may be a filter for it, or they listed the filter for the 4 speed trans I am not sure. GM does not list anything for changing filters in the 6 speed transmissions. If there is it would not be very easy to do since the pan is on the side of the trans not on the bottom like the 4 speed trans is.

Personally I wouldn't go over 60K on a fluid change, I prefer 30K just for piece of mind. It really isn't that much to do it when compared to pulling a trans.

I would not flush a trans on your own. You will run a risk of overheating and damaging components. I would only have a flush done with a machine to keep trans fluid flowing. If you are doing it yourself just do a drain and fill, but pay close attention to fluid level afterwords so you don't have any problems.
Well, you're certainly entitled to your opinion...

But, reality is reality. The flushes were done by shops, the trannys burned up on both cars within about 30 days, and that is that. Game over, and one person's opinion doesn't pay for another person's new transmission.

And a tranny for a RX300 is pricey, indeed. I don't think 65k was that bad (I wouldn't do it, though) for the first fluid change. That one is in court.

I agree with you on the frequency of the transmission fluid changes. I used to change out some of my F150's fluid every 25k by disconnecting the output line, and let it drain a few quarts.

I have a question for you and the rest of the group:

Exactly how do you check the trans fluid on the 'bu? Anyone notice that there is no transmission fluid level stick?

Is there a service plug or port that can be accessed underneath during my next oil change?
The 6t40 6 speed trans and 4 speed trans on the four cylinder is checked by warming the trans to operating temp and removing a plug on the trans. Then the trans is filled from the top till the fluid drips out of the hole. The 6t70 6 speed on the v6 has a dipstick and is checked at operating temp. The operating temp is between 180-200 degrees or drive the vehicle for about 15 miles to warm it up.

I do trans flushes at the dealer I work at. Everyone there uses common sense and doesn't flush a trans when the fluid is black and burnt or when there is high mileage and never done before. Brown fluid is as far as I will go with flushing because it doesn't indicate there is a problem. I know of shops that have burned up transmissions because of it being done when it shouldn't have been. No matter how it is done, albeit drain and fill or flush, it is good to just maintain the vehicle.
I hate to resurrect a thread but I can not find the type of ATF these trannys take?

The trans fluid is Dexron VI.
So, basically what I gather from all of this is that the damage is most likely to be incurred from a, very possible, transmission fluid over or under fill. Also, the possibility of pouring in the wrong fluid and causing damage. My trans fluid at 60K, when I changed it, was not burnt in any way just dirty from the friction material on the clutches. I do believe though that due to the mileage on the car and the climate that the car was in it fell under severe service and was due to be changed.

Checking fluid level on these transmissions varies between the 4 cylinder and 6 cylinder models. The 6 cylinder trans has a dipstick which allows for the fluid level to be checked, but to find the proper level for the vehicle depends on the temperature the trans is at. Same goes for the 4 cylinder version regarding temperature, but there is not a dipstick to check the fluid level. These are checked at a certain temperature and by removing a plug on the trans.

Both of these fluid level checks require knowing the trans temperature to verify it is at the correct level. If it is not at the correct level is when damage can occur. I am not sure if all I am thinking here is correct, but it is how I gather it to be from what I have read through all of this.
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That brings up a very good point in my mind.

If the temperature of the transmission, not necessarily the engine, is critical to proper filling, where's the transmission temperature display so I know when to check the level and adjust it as necessary? Why is the car now the expert and not the owner? I asked the car but it didn't answer.
I wish it were as simple as asking the car what's wrong or how are you feeling today:D. It would save a world of trouble and make my job easier.

The only thing I have seen the trans temperature reading on is the trucks. The cars' trans temp reading is pulled up with the tech II.

I am going to add how to check fluid condition and hope this doesn't cause problems.
-The fluid should be red in color. When it is brown it doesn't mean there is an issue, it is just the material from the clutches, and happens under normal use as stated before.

-If the fluid is black or has a burnt odor then it should be checked for excessive material or metal, and driven and checked over for any issues. If there are no other issues the fluid is safe to change.

-If the fluid is milky in color it may indicate a contamination issue of water or coolant. This is just bad no matter what.
Its not very difficult to change ATF people. No you dont have to worry about all the fluid temperature nonsense. Thats ONLY if you have have no idea how much fluid to fill. Its simple, drain the fluid and collect it all. Measure how much was drained, pour same amount back in. No need to bother with measuring temperature while filling the fluid.
Checking the fluid level is important to keep the trans in good shape though. Doing it properly is what is going to keep it that way. The fluid temperature needs to be in a certain range to properly indicate the level, so yes the fluid temperature is important. What's to say the fluid level was correct before draining it? For how expensive a trans is to overhaul it is better to air on the side of safety. What I there was a leak that the owner didn't see? There are to many risks to do it as simple as drain and fill unless you know for sure it was fine before.
I agree with what you are saying. The problem is GM doesn't agree with you. That is why they make it so hard to check the fluid. Also they state in the owners manual that we don't have to check the fluid. They say we don't need to change it or the filter. Don't need to worry about it at all, just run it till the tranny pukes. This is a huge design flaw by GM.

You bring up some good points about drain and fills, the fact that if you measure what you take out it still might not be right, due to leaks and what not. But you also have to consider GM says not to worry about the fluid until there is a problem. So if there is a leak it will drain all the fluid unless you realize it and then kill the tranny. So in reality it doesn't matter if it was leaking or not, because GM tells us not to worry about it, and doesn't give us an easy way to check the level to see if it's leaking. Sometimes you won't notice a small leak untill it's to late. To the average person this sounds great, never have to change fluid, never worry about fluid level, etc. But to anyone that has any mechanical knowledge this is a joke.

You say there are to many risks to doing a drain/fill and using the fluid that comes out to measure how much to put back in. You are correct that it's not the right way to do it but it's still better than just leaving the old fluid in and never changing it. If there is a leak it doesn't matter if you change the fluid or not, either way you still are going to be short. And GM has decided not to give us an easy way to check the fluid level and they specifically state in the manual not to worry about the fluid unless there is a problem. Which a lot of the time if there is a small leak you will not notice it till it's to late.

Thanks GM, for a crappy design.

You sound like you work at a dealership or are a mechanic? If so is there a way for the average person to check the level? Mine has a dipstick, but as you stated you have to check it at a certain temp. So is there a way to tell the temp to check the fluid? I know honda says to run the vehicle for 20 minutes and then check fluid to get the right level. Is there a time to run the car to get temp to right level? Or some other way to tell the temp to check the fluid? Thanks
I don't agree with GM saying the fluid never needs to be changed, but there isn't anything that says in the manual stating the fluid should never be changed. I have changed my fluid out at 60K and did not like how the fluid looked, it wasn't burnt but dirty from friction material. I have not had a single issue since, in fact it seemed to shift smoother than before. I am saying it is important to be sure the fluid level is correct because that is what will cause it to fail. I t is better to be safe than sorry. Yes, I do work for a dealer, but that doesn't mean I agree with everything I read. For the 4 cylinder owners it is very much a pain to check fluid level, and I hate it. For the 6 cylinder owners it is much easier since you have a dipstick.

The fluid range on the dipstick is also the operating temperature of the trans lowest being a certain temp and the highest mark a certain temp. Best way I can say to check the fluid level is drive it for 10-15 miles to be sure it is up to operating temp then check it on level ground. I don't agree with how things are done anymore, but there isn't anything I can do about it. I think it is more a design to keep the average owner who has no idea what they are doing from messing with their car, but the issue that causes is they follow what the manufacturer says to do.

I still stand by the older standards and don't follow the oil life monitor and change my fluids as I see fit. I have payed for the car and it is my responsibility to pay for repairs when it goes out of warranty, so I am going to take care of it in my way. The other thing is most cars end up falling under severe service in a lot of the climate regions, which is the other reason I find it necessary to change the fluid. All I was trying to saying in my previous posts that it is important to be sure the fluid level is correct to save from the issue of a bad trans later.
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Hey chevyguy8893
I am used to checking tranny fluid level in cars that required the tranny warmed up, run the shifter thru all the gears, put it in park. Leave the engine idling. Then pull the dip stick.
On a 2010 V6 Malibu, do you check it with the engine off, or leave idling? From what I have read here it sounds like with the engine off. I dont know for sure
It is still checked with it running and in park. The only difference with these dipsticks, if I remember correctly, is they don't have a cold range for checking fluid level.
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