pcolt94

When I got the car fluid was real dirty and changed it several times with a vacuum device and then did the filter. 40,000 miles later I did the oil again. Now with 60,000 miles later I was getting ready to do the oil which is not in bad shape but doing it regardless. I have always had 60,000 miles max in my head for decades as to when I changed the oil.

So now I have put the project on hold because I think I am going to do the filter at this time to again. The interesting thing is I decided to look in the owner's manual just to see what it might say. And they think oil and filter should be changed at 15,000 miles which nice to say but that’s GM car and they are being cautious.

383vett

Twice a year (every 75 runs), or more if the tranny blows.

Larry/car

The fluid that comes with the car goes with the car, or never.

JrRifleCoach

50-75,000 miles max for general duty.

WVZR-1

Which fluid? The Dexron III is no longer available so it's either GM Dexron VI, a MultiPurpose such as Valvoline MaxLife Dexron / Mercon Automatic Transmission Fluid or would/will you go out of your way for some Castrol TranSynd that is Dexron III/Allison Spec 295 synthetic? The later is something $40 -$50 a gallon and a little difficult to get. It is the "real stuff" though!

gerardvg

The dirty trans fluid is usually from the clutches wearing, i have never had an auto trans last long enough/ do enough miles to warrant a fluid change.
The fluid usually stays bright red till she dies brown or dirty fluid means game over almost, don't know how you got so many miles out of yours...... she is not named Christine is she ...

LT4 F45

I think that you had been over cautious from changed it over and over but i changed my ZF and diff fluid at 41K with Amsoil just to make sure that after 17 years everything is fresh under there...

93Rubie

Depends on how you use it. I change my DD automatic every 30K, just a flush, not a filter change.

Most manufactures no longer recommend any transmission servicing. I call BS on this. GM is REALLY bad for it. NO dipsticks what so ever.

Fluid even with the best additives breaks down with time, contaminants, HEAT, and other factors. My 2001 Ford Focus DD is at 117K+ on the original transmission. I flushed last at 95K. I bought the car with 59K on it.

Most modern (MY05+) transmission should be able to go 100K+ with no fluid changes and live. I see a LOT of older Nissans with 150K+ on the auto's and they are fine. Some have had fluid changes others have not. The older Altima's/Sentras from the early 2000's seem to be bullet proof tranny wise.

However, my personal belief is that if you want to keep the vehicle every 50-75K is best. Especially if you do anything that gets the fluid hot, like towing, heavy hauling or just hauling A$$.

383vett

This past year I used Amsoil no slip racing tranny fluid and have had not issues with 150 runs. The stuff is expensive at $10.50/qt but it flat out works.

93 ragtop

FWIW I have been using the Mobil syn ATF in my vette and work truck. The truck has over 123000 miles on it with over 100000 miles of that being the mobil fluid. Also, by all means change the filter. I have a good friend who has been rebuilding transmissions for over 30 years now. He told me the main reason a flush will kill a transmission is, sediments in the trans break loose and are lodged in the filter. The transmission then starves for fluid and burns up the clutches. Its crazy not to change the filter for no more then it cost.

WW7

I change my trans fluid and filter every 30,000 to 40,000 miles, alway have , always will ..WW

eaglevision993

I change mine about once a year regardless of mileage but no further than 30k miles. And I never lost a transmission so far. I also put a bottle of Lubegard Red in older transmissions.

It may be a little overkill but I do the change myself and what is the price for fluid and a filter compared to a new transmission.

A good additional trans cooler is also a good investment to prolong fluid and trans life.

l98tpi

I change the fluid and filter annually. Around 500 to 750 racing miles.

Cliff Harris

I put a pan with a drain plug on my trans. It makes it a LOT easier to change the fluid, which encourages actually doing it rather than putting it off forever.

What I have done in the past is change the fluid and filter when the trans makes a funny noise or does something weird. One time I drove 400 miles without stopping and the trans didn't downshift when I came to a stop at the end of the freeway offramp. Changed the fluid immediately and never had a problem like that again.

barefootskier

Here is some food for thought. I was a technician for a local Ford dealership for 26 years, until I had back surgery and that all ended.
Anyway, when I was at the Ford Training Center in Buena Park, CA. taking an Electronic Automatic Trans Class, the instructor greeted everyone on the first day, then asked how many actual transmission techs were there in the class, That is, how many techs that do transmission work on a daily basis? Well about 10 techs raised their hands. He then asked how many of those techs actually ever change the automatic trans fluid in your own personal vehicle? They all just looked at each other and no one raised their hands. He said, when something breaks and you have to open it up and work on it right? He then went on to say that years ago when fluids did not have the viscosity properties that they do have now, he could understand that fluid would get burnt and need to be changed. But with today's fluid properties, the oil viscosity doesnt break down until something like 400 degrees and he said that the seals will melt out of the transmission case at 350 degrees.
He then said, but we will certainly change it for a customer if it gives him a warm and fuzzy feeling, but it is not really neccessary.
In fact when I left Ford in 2006, alot of the transmissions didnot even have dipsticks, because the transmission was supposed to sealed from the factory and they didnt even want us to open up the case on most vehicles. If there was any problem, they wanted us to just put in a new sealed unit, which came with the fluid in it that would last the life of the transmission.

leesvet

Trans fluid does not actually "break down" as described...it becomes contaminated with wear materials and micro fine particles of semi solid matter that gets suspended in the fluid. With better filtration in todays systems, the problem has been solved for the avg unit.

Many new car mfg seal off the unit because its a matter of filtration, not fluid lifespan,. Its hydraulic fluid, its made to go forever unless contaminated.
That being said, these older GM trannys DO have wear parts. The fluid is the best indicator of when its time to change. I use a suck-pump to pull out as much as possible thru the dip stick a couple times a year IF the fluid is no longer pink and clear. Change the filter every couple yrs after a couple fluid changes.

The other reason to pull the pan to get at the filter...you can see the sludge collection in the pan corners and gauge the health of your unit. Getting that crap out helps keep the remaining fluid from picking up more solids and sending them thru the system. NOT everything gets filtered everytime...some trash is suspended and still circulates.Filters may collect anything 10 micron or bigger but 8 micron particles can still slowly eat away at seals and soft metal wear surfaces...

Don;t know if anyone else saw this recently on HP TV....an episode about this subject.
They drilled a hole in the Torque Converter to facilitate draining the fluid from there too...since the TC holds as much as the pan this makes good sense. The used a pop rivet to plug the hole afterwards. I assume that the next fluid drain would require drilling that rivet out...It seems like it would be a fairly simply upgrade to make a tapped hole and an allen screw with some locker.

I also use synthetics. I used to have access to fleet reports and studies that had clear proof that synthetic trans fluid lowered the failure % rate dramatically in fleets that were already in service, So simply changing your stock fluid to a synthetic will add life to the trans.

heat & contamination are the enemy to an auto trans. Maintain accordingly.

pricesgarage

50,000 miles is best do not flush it just change the filter and the fluid but a good gasket the rubber ones are junk from the auto parts store if it has around 100000 miles add some lucus transmission additive

l98tpi

The reason Ford owners don't need to worry about the trans fluid is there is no need to prolong a throw away car.

Back to the subject of tranny fluid. Trans fluid does last a long time and can last a long time. It is the additive package, just as in engine oil, that breaks down and will over time turn to an acidic fluid. And we know what an acidic fluid is going to do don't we? If my trans didn't get so warm during events, in hot weather will get to around 250, I would change every two or three years. It is the heat that breaks the fluid down and decreases the life of the fluid and additive package.

C66 Racing

Dexron III no longer an approved GM spec, but most aftermarket oil companies still make oils that meet the spec:
AMSOIL Multi-Vehicle ATF (Product Code ATFQT)
AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G)

93Rubie

Ouch that burns.

I'll take my Ford Focus over ANY GM Cavailer or Cobalt ANY day. WAY better car. IHMO, Ford has been and currently IS the best domestic manufacture overall. If GM did the rest of their stuff as good as the Corvette they would not have ever had financial issues.

I know some feel flushes are not a good idea. I disagree as long as the transmission is clean inside. Most of them are. No gunk to knock loose means no reason not to flush. You get more of the old fluid out than just a drain. The TQ converter still is full of a lot of fluid on just a pan drain. Heck, some newer transmissions do not have filters in them. Just a screen much like a oil pick up. No reason to pull a pan on those.