Automatic Transmission Fluid Change


I’m in a real quandry, as I have limited funds, and need to have the trans fluid changed in my 2005 Malibu, as it now has 55,000 miles on it. This would be just routine maintenace for the trans. There are two choices, change the filter and five quarts of fluid, or take it to the local oil change place, and have them hook it up to a machine that pumps out all the old fluid, and replaces all of it with new fluid. However, the filter is not changed. I have heard many horror stories of transmissions failing after the latter method. Can you damage your trans by having the fluid pumped out? Is it bad not to change the filter? Is one method better than the other. I’ve asked this question to five different shops and the majority have been negative against pumping all the fluid out of the trans. Note, these shops did not offer that service to begin with, so perhaps they are just being biased.

Thank you very much. I earerly await your answers.


Brian Maichle


The idea of having the poorly trained kids at a typical oil change place doing ANYTHING with my transmission is a scary thought.

Whether you do it, or you have a real mechanic do it, you should simply change the fluid and the filter. A flush–such as what is done at your quicky lube place–has a very real probability of doing damage, especially since they are not changing the filter. Throw in the chance of their employees using the wrong fluid or making some other type of bone-headed mistake, and you have the sure recipe for damage to your very expensive transmission.


You are much better off dropping the pan, checking it for debris, cleaning it out, changing the filter, reinstalling pan and refilling. Yes, the filter must be changed. STAY AWAY from those fast lube places. The kids they hire off the street have no business touching an automatic transmission. These shops buy these fancy flush machines because they are easy and quick and make them a fast buck. They hook them up, run them for a few minutes and send you on your way without even changing the filter or examining the pan. You wouldnt believe the number of automatics crossing my bench every month which are there due to improper servicing. I have no problem flushing a transmission but only if it is done properly by a qualified transmission tech and the filter is changed before the flush is done. How does your fluid look right now? Does it look pink like it should or does it look brown and contaminated?


Many modern cars tranny’s don’t like to be power flushed. It’s best just to drain and refill.

The BEST thing you can do is drain tranny then drop the pan replace the filter (if there is one) and then refill with fresh fluid.

The second BEST thing you can do is just drain the tranny and refill with fresh fluid.

Change the filter and add clean fluid. This is the method specified by the manufacturer.

At this mileage a flush probably wouldn’t hurt the transmission, but I wouldn’t go to a chain oil change place even to ask directions. These places, not their machine, cause the problem by employing young people who neither know nor care about proper maintenance. They’re just trained to sell more flushes (power steering, brake fluid, etc, etc).

No matter which method you choose, go to an independent mechanic, not a chain store.

Thank you to all for your replies. I have decided to take your advice and have the fluid and filter changed at a small local trans shop. I think this will be the most conservative approach. I did e-mail this question earlier to CarTalk, so they might address it seperately on a future show. Thanks again.

My son is in the middle of one of these flush only/don’t drop the pan or change the filter debacles right now.

The transmission in his Lincoln Aviator had a very subtle 2/3 shift flare and since the vehicle was under warranty I told him to take it to the local Ford dealer and have them look at it, along with verifying up front and in advance that warranty would cover the problem.

So after being gigged for 244 dollars worth of fluid flush only he now has a vehicle that is close to undriveable. The vehicle now has a 1/2 stutter, 3/4 stutter, and the subtle 2/3 shift flare has now become a severe 2/3 shift jolting.

As I type this the vehicle is back in the shop again and the problem is allegedly a faulty shifty solenoid. Since I’m not buying this diagnosis for one minute it’s unlikely that things will be ducky when the vehicle is returned.

The service manager’s reason for not dropping the transmission pans when doing a transmission service? (And this is exactly what he stated to me)
Quote: “There’s too great a risk of the transmission pan leaking when we put it back on”. Jeez.

“There’s too great a risk of the transmission pan leaking when we put it back on”

That’s one lame excuse. OF COURSE there’s a higher chance it will leak if you pull it then if you leave it on.

WOW! If this shop can’t properly install a transmission pan gasket, I would not let them touch my car.

You should ask the service manager how much it costs to replace a valve cover gasket. If he gives you a quote, ask him why his people are capable of successfully installing one type of gasket, but not another. You could also ask him how he would repair a leaky transmission pan gasket. Would he turn down the job because “There’s too great a risk of the transmission pan leaking when we put it back on”?

This service manager is obviously a tool.

I admit that I have never checked the transmission fluid since I bought the car new. It never leaked and always shifted. I tried to check it today, but could not find the dipstick. I read the owners manual and it states that there is no way to check the fluid in the automatic transaxle, and that it should be brought in for service if it leaks. I will be taking it in for a screen and fluid change next week. Thanks

When the service manager made the statement about being afraid to risk a pan leak I made the statement that, "well, you must have some pretty incompetent techs back there if they can’t remove and install a transmission pan without it leaking. You do realize that pan R & R is Kindergarten level mechanics don’t you?"
Followed by “uh, well, uh”.

I can’t wait to hear his response when this alleged faulty shift solenoid is replaced and the problem is not cured. ((No codes present)
Probably about as good an example as can be found why a transmission should have the pan dropped and filter changed before flushing it.
My feelings on this are twofold.
One is that the flush only will simply stir up the crud in the pan.
Two is that if there is crud in the pan then there’s likely a more serious problem.

He also had no response when I asked if they also changed engine oil without changing the filters. :wink:

dear readers

Do some cars come with trans fluid drain plug without taking the pan out to drain the fluids?

Yes…but NOT all.

Here’s one way to think about it - how did all those millions of trannys survive before the (relatively recent) invention of the flush machine? Answer - they did fine with a pan drop and filter repace (maybe better). So don’t worry about it, the pan drop is a good, and maybe better, way to go.

Texases makes an excellent point.

I have never had a transmission flushed, and instead, I change the fluid and filter every 30k. And, I have never had a transmission failure or even any symptoms of transmission problems.

I suggest that you wait another 45,000 miles. I don’t own a Malibu, so I don’t have an owner’s manual for one. But suggests changing the filter and AT fluid at 100,000 miles. I imagine they got the information from the owner’s manual. Check you owner’s manual to see when Chevrolet recommends it. If you don’t have a lot of money, why change at half the recommended service interval?

Lots of transmissions had torque converter drain plugs allowing you to get 95% of the fluid out rather than about 50%.

What is wrong with pulling off the cooler lines and pumping the fluid out?

Ford, I think, took to using reusable, silicone transmission pan gaskets a long time ago. I agree with the dim view of the service manager for saying what he did. What he should have said is that Ford’s recommended procedure is to pump the fluid out using a machine and the cooler lines and not bother with the pan or filter or TC drain plug even if it has one.

My problem with the flush machine is the cost, easily double or triple the pan drop, and they don’t look at the filter.

Service that transmission with a pan drop and fluid filter change every 25-30k miles regardless of what the owners manual says.


Just a couple of comments to add with the ones I made previously in this thread.
The service manager and writer both stated that “we haven’t dropped a transmission pan here in 15 years”.
They had no response when I commented that “maybe that’s why I’m sitting here going round and round with you right now”.

An email to FOMOCO asking them to clarify the company position on transmission fluid changes got nothing but a generic response. The owners manual states “change transmission fuid” without specifying flush, pan drop, etc.
FOMOCO stated that we “should see one of their fine network of Ford dealers who have the experience, training, and expertise to answer any questions”.
My follow-up was that why should we discuss anything with someone who has no clue.

As of a short time ago, my emails have been bumped further up the corporate ladder and I’m ignoring FOMOCO at this point.
They also called my son a bit ago and told him his car was “fixed”. We’ll see.
The part about the faulty shift solenoid being special ordered?
Apparently that solenoid thing is a dead issue now and the problem was “only a sticky valve body”.

They also stated that “we’re waiving the 100 dollar deductible on the extended warranty”. BS

I have a feeling that this is not the end of it and considering what has transpired my feeling is that “sticky valve body” ranks up there with the “bad gas” diagnosis.
The waived deductible tends to make me think that ESP warranty was never involved to begin with and the dealer service dept. is just in full CYA mode.

Bottom line is that his car had an almost unnoticeable 2/3 shift flare until the flush was done. Within 2 miles after picking the car up it was almost undriveable. It had shift problems in every gear with the 2/3 shift being so bad it would almost slam you into the seat.
Flushing is not a problem; not dropping the pan and changing the filter is.