Does ATF degrade with time or mileage or both?

Joined
Jun 13, 2006
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NJ
Hi everyone,

I have a quick question about my 2011 Nissan Titan 4x4 pick up. I purchased the truck brand new ten years ago and it currently has 14,000 miles on it. It lives in the garage and doesn't do any heavy duty work. It is never used in the winter, it just sees use in the spring and summer.
With that being said, the ATF is now ten years old. Should I be doing a trans service at this point or is the ATF probably fine given the low mileage? The truck has done limited towing, and never anything very heavy. If you think the ATF should be changed, is it a simple drain and fill or is a flush needed?


Thank you!
 
The end of your post, "....is it a simple drain and fill or is a flush needed?" shines light on your situation.

At 14,000 miles the likelihood of needing to replace all you fluid (i.e. bad fluid) is low. Yes, you've towed a bit with it but nothing taxing.
Were I in your shoes I'd consider taking the vehicle to 25,000 miles and doing a drain & fill. While that might be early, there's no substitute for seeing and possibly sending a sample off for analysis. It's vague and arbitrary.

The next person might suggest the truck's 15th birthday (assuming 21,000 total miles-same miles per year and no heavy towing) for the very same, inexpensive, easy to do service.

If the fluid drains black, you can repeat D&F or do a pump out. If the fluid drains clear and perfect, the joke's on you and you're only out the 4 qt. of fluid and maybe a filter.

Has searing heat been part of your truck's past decade?

My friend's 2019 (same truck) lags going into reverse and he only has 27,000 miles. I suggested a D&F just to see. There's no telling how much his truck, bought with 1,200 miles, was beaten.

Be alert to the fact that a "dipstick wipe on a white rag" gives you the smallest inkling of condition. The smell might tell you more.

Care for your truck and PM me if you ever want to sell it. I'm in Hackensack.
 
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I wouldn't worry about the time which has lapsed, your mileage is nothing. I changed fluid from my old Mercury in 2017. I last changed the fluid and filter back in 1993. Only 45 k miles had lapsed since then. I was fortunate as the converter has a drain plug. The fluid was still bright cherry red, no debris was in the pan or filter. If your fluid still looks in good shape, I would run it w/o a fluid change. At 14k milles, that fluid probably looks like new.
 
With the transmission virtually airtight and no combustion products and moisture like with motor oil I figure time is pretty much a non issue.
If it were me looking for a way to give this truck some fluidic LTC I'd change the brake fluid, if it hasn't been done in 5 years.
 
Don't forget..... there is wear metals circulating around in your trans.......... therfore I'd go ahead and do three D&F's between now and the time you store it away for the winter.
 
I wouldn't worry about the time which has lapsed, your mileage is nothing. I changed fluid from my old Mercury in 2017. I last changed the fluid and filter back in 1993. Only 45 k miles had lapsed since then. I was fortunate as the converter has a drain plug. The fluid was still bright cherry red, no debris was in the pan or filter. If your fluid still looks in good shape, I would run it w/o a fluid change. At 14k milles, that fluid probably looks like new.
What fluid did you use?? I must know
 
What fluid did you use?? I must know
I had a collection of old Valvoline and Castrol Dexron 2 unopened bottles which I used to refill. Amounted to around 12 quarts altogether. Sure I could have used something more modern but the old Ford AOD specified Dex 2, that's what I used in it from day one and I had all this ATF sitting around so that's what I used from my stash.
 
I changed fluid from my old Mercury in 2017. I last changed the fluid and filter back in 1993. Only 45 k miles had lapsed since then.
Mercon fluids were very good, non hygroscopic.
The newest batch of Asian transmission fluids are very hygroscopic, they will absorb water like is no tomorrow.
It lives in the garage and doesn't do any heavy duty work. It is never used in the winter, it just sees use in the spring and summer.
If the temperature in garage dips a lot, the air inside transmission pan will cool down, "shrink" and will suck in more air from outside trough the breather. That brings in humidity.
When the air warms up, the expanding air is expelled.
That's how in time humidity is building up in transmissions that are not driven enough in winter to heat up and vaporize that moisture...

I would do a drain an refill now. Is not that expensive (compared with transmission) to even be a question. But that's just me...
 
Don't forget..... there is wear metals circulating around in your trans.......... therfore I'd go ahead and do three D&F's between now and the time you store it away for the winter.

This is speculative unless quantified. Is there an assumption embedded that the magnets and filters in there are not doing their jobs? Of course there are some dispersed wear metals, low ppm of each. This is different than particulate. So what exactly is in there doing hard that justified the three d&f?
 
So what exactly is in there doing hard that justified the three d&f?
I also do that 3 D&F to replenish most of the fluid. One D&F mixes old with new fluid. If there is humidity or just degraded additives, this repeated procedure gets rid of most of all. It's a bit expensive, but, if you have a drain bolt, is easy.
I believe in overspending on oil than on fixing transmissions.
 
I also do that 3 D&F to replenish most of the fluid. One D&F mixes old with new fluid. If there is humidity or just degraded additives, this repeated procedure gets rid of most of all. It's a bit expensive, but, if you have a drain bolt, is easy.
I believe in overspending on oil than on fixing transmissions.
That doesn’t answer the question. We have no objective evidence that there are depleted additives or moisture.

I’m all for some D&F in some circumstances, but we don’t have evidence that this fluid needs changing.
 
I always thought of trans fluid as getting filled with used clutch material. Not sure a magnet catches all that. Does the filter get it all? I understand that the newer trans fluids don't sheer down as much ( dex 6). Would draining the fluid and replacing, removed clutch material that the filter can't catch?
 
We have no objective evidence that there are depleted additives or moisture.
It is useless to talk to people like you. What do you want, a $100,000 study to see if you should spend $20-30 in a oil drain and refill?
...getting filled with used clutch material. Not sure a magnet catches all that.
Of course not, because it is non-magnetic friction material. If you have lots of magnetic material shavings... IMO it is probably too late.
Automatic Transmission Bands Automatic Transmission Brake Bands are flexible steel plates lined with organic (cellulose) or semi-metallic friction material. The lining absorbs transmission fluid to aid in heat dissipation.
 
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It is useless to talk to people like you. What do you want, a $100,000 study to see if you should spend $20-30 in a oil drain and refill?

This is really simple. Did you actually read the OP?!? 14k miles. Not 36k, which was a traditional change interval, or longer. 14k.

So the question isn’t wear materials, friction particles, etc. it’s ambient temperature oxidation, and moisture. Did you actually read the OP? The conditions that the vehicle is stored and used at? Neither of those scenarios concern me.


I always thought of trans fluid as getting filled with used clutch material. Not sure a magnet catches all that. Does the filter get it all? I understand that the newer trans fluids don't sheer down as much ( dex 6). Would draining the fluid and replacing, removed clutch material that the filter can't catch?

Sure, much of the friction material may not be ferrous. You’re making an assumption that the small particles aren’t dispersed, so they’re sitting in the sump ready to go, and that there’s a lot of them. I can’t say I’ve ever seen a recommendation based upon detergent, dispersant content, or anything else to change the fluid at 14k mile intervals. The old 36k intervals had everything to do with shear stability, and nearly nothing to do with small amounts of friction material at intervals much below the stated OCI. Even when ATF fluids were much lousier than they were in 2011 or today.
 
Hey if the volkswagen 2.5 i had could go 180,000 miles without a fluid change, there is the answer.

Its probably fine, 2011 was a great year for ATF, very stout.
 
I have a quick question about my 2011 Nissan Titan 4x4 pick up. I purchased the truck brand new ten years ago and it currently has 14,000 miles on it. It lives in the garage and doesn't do any heavy duty work. It is never used in the winter, it just sees use in the spring and summer.
This isn't some exotic or fun sports car. Why did you buy it, new no less, and 4WD no less when you don't even drive it in the winter, to only use it 1,000 miles a year? I can understand if you say you are rich, but most people here would be scratching their heads.
 
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