Automatic transmission longevity: fluids & OCI

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When you say drain and fill, are you just referring to the pan?

In recent years, I've opted for complete fluid exchanges every 60k. The guy I go to uses an exchange machine without cleaners and a synthetic multi-vehicle fluid.

So far so good, my explorer had 175k miles on when sent it down the road. Trans worked great, despite the heavy towing and off roading I frequently did with it.

I've had great luck over all with synthetic fluids. My 89 thunderbird had 209k miles on the AOD trans. And it worked great. Solid predictable shifts and never missed a beat.

Most of our vehicles don't have a drain plug on the transmission pan, which is why I've opted for the fluid exchanges. I hate dropping the pan on a transmission. Messy miserable job....

Might have to rethink this going forward, though, as more and more new transmissions have a thermostat making a heated flush machine mandatory for a fluid exchange, and not everyone has one or knows how to use it correctly.
 
My 2003 Saab 9-5 has an Aisin AF33 5-speed auto, and draining the ATF from it is as easy as draining engine oil. In the Saab community, a best practice for many of us is to do a drain & fill every second oil change. On the Aisin AF33 a drain & fill involves about four liters of fluid, which is a little over half the capacity of the system. I use Amsoil ATF in mine, so for about $40 I'm exchanging about half of the fluid, roughly once a year. It stays nice and fresh and the transmission runs as smooth as a sewing machine (knock on wood!).
 
05 Dodge Ram 545re trans. Dropped pan and changed both filters at 196k miles. Only time it's ever been changed. In fact only time trans has ever been touched.
Fluid was definitely used, but not junk. Pan was very clean. I was impressed.

Mainly commuter vehicle, though has towed some 7000 lbs loads before. It's wife's truck, she's hard on the go pedal and hard on the slow pedal.

I do pull dipstick once a year or so and check fluid condition.
 
Vehicle is a 2003 CR-V.

All I've ever heard about Hondas are to use OEM fluid, be it Z-1/DW-1 for the transmission or the specific power steering fluid. Since the power steering fluid on a Honda is an entirely different beast than regular ATF or PSF, I did a turkey baster drain and replaced the equivalent of one bottle (12 fl oz). I was extremely tempted to get the Prestone Honda fluid but went OEM. Steering is improved and smoother although I should do another in a few weeks; the old fluid was extremely dirty.

ATF drain and fill was done with Castrol Import and contrary to naysayers, shifting has improved quite a bit from the old fluid that was a dark, dirty red. Just over 3.5 qts came out and that's what went back in. I'll give it another couple weeks before doing another drain and fill to get it closer to the cherry red color of fresh fluid.
 
Originally Posted By: meborder
When you say drain and fill, are you just referring to the pan?


There are two schools of thought.

One is to drop the pan, clean it, replace the filter if it has one, and add enough replacement fluid to place the fluid between the hash marks when hot.

Advantage: This allows a slow cleaning process to occur. Disadvantge: You have to do this three or more times to get a majority of new fluid introduced. Good for the do-it-yourselfer.


The other is a complete drain and refill via a machine that uses the AT pump (while engine is running) to suck in new fluid while "purging" the old fluid. Advantage: This process allows the torque converter fluid to be purged as well, in real time. Disadvantage: One time cost is higher since you pay for the labor, machine pay-off, and fluid. Generally not for the do-it-yourselfer.

Now some do-it-yourselfer's will identify the low pressure (intake) hose and the high pressure (output hose) at the radiator, disconnect it, and do their own complete drain and refill using the AT's own pump.
 
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Originally Posted By: meborder
When you say drain and fill, are you just referring to the pan?


Drain and fill, as far as I'm concerned, would be replacing only the fluid that's in the pan. This could be done by pulling the drain plug, if equipped, or dropping the pan as required for vehicles without a drain plug. This would typically replace 35-50% of the system capacity depending on the vehicle.

Flushing, on the other hand, would involve replacing most (95%+) of the fluid via the feed/return lines.
 
For anybody who has a Toyota RAV4, just use the drainplug in the pan to drain then refill it.

It was a pain in the neck taking off the splashguard off the belly of the vehicle, and getting it back on properly. There is an access panel in the splashguard to the drain pan bolt, I should have just done that and been done with it.

I wanted to drop the pan and inspect the filter, and clean it all up. Never again.
 
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Originally Posted By: JustinH
For anybody who has a Toyota RAV4, just use the drainplug in the pan to drain then refill it.

It was a pain in the neck taking off the splashguard off the belly of the vehicle, and getting it back on properly. There is an access panel in the splashguard to the drain pan bolt, I should have just done that and been done with it.

I wanted to drop the pan and inspect the filter, and clean it all up. Never again.


Same here.

On my Frontier 2012 4X4, I drop the drain plug and refill. I measured the amount of fluid drained to be 3.5 Liters, and this is the exact amount I replace.

On my 2008 TrailBlazer, I replaced the drain pan with a Mag-Hytech pan that now has a drain plug.
 
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I'll state here what I stated in a different thread because I think it is applicable:

Quote:
Today's ATF fluid blends such as Dex VI and other LV ATF's are much better than the older Dexron/Mercon fluids of yore due to the enhanced additive chemistry and improved base oils.

The newer additives offer enhanced dynamic friction retention, less viscosity shear, and improved oxidation resistance. But these fluids are NOT the holy grail.

My recommendation for periodic fluid changes is only overkill against some manufactures recommended change intervals which attempts to "peanut butter" OCL's against long term, low mileage, and mild driving conditions.

My recommendations are NOT overkill for transmission longevity.

One thing not discussed is particulate loading.

Initial machining, assembly, and run-in traps and accumulates particulates which could cause a snowball effect in terms of wear, hence changing out early gets rid of a major amount of particulates due to this situation.

Later, composite clutch material particles and ferrous and aluminum metallic particles [from gears and bearings] become dispersed which can cling to valving and actuator surfaces causing delayed shifts or "slams."

Periodically changing out the ATF and filter (if it has one) has these advantages:

1. replenishes the additive package which has degraded,
2. dilutes the particulate load which accumulate over time.

If the tranny has a filter, it cannot catch those very fine particles than get into piston interfaces and valving clearances.
 
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2007 Volvo V70: drain and fill at 10k, cooler line exchange at 20k. Mobil 3309. Dimple magnetic drain plug.
1993 Volvo 240: drain and fill at 10k, cooler line exchange at 20k. Any full syn that meets the Dex III spec. Dimple magnetic drain plug + inline remote Wix filter.

Past cars:
1989 Volvo 740: cooler line exchange every 20k, Dex III conventional. Shifted perfectly until car totaled at 338,000k.
1996 MB C230: cooler line exchange every 30k, MB spec fluid. Shifted perfectly until car totaled at 148k.

I've never had a transmission failure or or one that needed a rebuild.
 
When I first change my ATF I do at least 4 drain and refills over a period of about a week. I don't take pan off or unhook any hoses. I just measure how much drains out and replace it by that amount (especially if there is no stick to check the level with). I try to get at least 75% new fluid in.

From that point on, I do a single drain and refill every 10K with the appropriate Amsoil ATF.

There's an online "ATF Drain-and-Fill Calculator.xlsx"

It's really cool.
 
The dramatic change is what poses a risk, I guess.

The transmission likes when the fluid properties are stable. And doesn't like when they suddenly change - the mechanism needs to re-adjust, at a cost.
 
I only hoped it was as simple on my Lexus.

Love my Highlander which has drain and fill ability, do it every 30K miles. My 5sp auto is much better than my jerky 6sp auto.

More sophistication more pain.
 
Originally Posted By: Gebo
When I first change my ATF I do at least 4 drain and refills over a period of about a week. I don't take pan off or unhook any hoses. I just measure how much drains out and replace it by that amount (especially if there is no stick to check the level with). I try to get at least 75% new fluid in.

From that point on, I do a single drain and refill every 10K with the appropriate Amsoil ATF.


I think that is a good practice.
 
Originally Posted By: RPMster
Please share your personal experience with automatic transmission longevity in your current and past vehicles.

How were they used: Easy freeway commutes? City driving? Heavy loads?

How did you maintain your automatic transmission: OCI, drain/fill or flush, serviceable filter, factory fluid or multi-vehicle fluid, DIY or dealer/shop, etc?

Did the transmission have any factory defects (either non-typical defects, or well known defects that were common to that vehicle model)?

Any other details that might be relevant?



I have personally maintained my vehicles and the vehicles owned by my immediate family members (parents / brother / sister-in-law / brother-in-law / etc). I have never had a transmission failure or any kind of other transmission problem with vehicles that I have maintained.

My first car was a 1996 Chrysler Intrepid (Dodge Intrepid for our American friends here!) My dad bought it brand new, and then got a company car a year later, so I assumed use and care of this car (and eventually bought it off him as he simply didn't need it). Car was used for in town commuting, lots of downtown city driving, frequent trailer towing to cottage country at 70+ mph (jet ski trailer - about 1,000 lbs), and other miscellaneous use. I don't abuse any of my cars, but I generally do not drive "easy" either. This car (as many Chrysler products of that vintage) had a terrible transmission, and they were prone to failures either within or right after the warranty period. I first changed the fluid at 80,000 km with Amsoil ATF, and added a nice sized transmission cooler inline with the built-in stock radiator cooler. This took me to 160,000 km, when I changed the fluid / filter once again with Amsoil ATF, and never touched it again until I sold the car with 330,000 km on it. No transmission problems whatsoever, and car shifted perfectly when I sold it.

My mother had a 1997 Oldsmobile back then. I changed the fluid at around 100,000 km to Mobil 1 synthetic ATF. Never touched it again, and the car worked perfectly until it was written off in an accident (not her fault) at around 220,000 km. No towing, relatively easy driving (but mostly city with some infrequent highway trips).

My family inherited a 2001 Chevrolet Venture from my dad's company back in 2003 (for next to nothing compared to what it was worth). This van is now mine (as an extra vehicle / work-horse / trailer towing vehicle). It is no longer driven on a daily basis. Transmission history... First changed fluid to Amsoil ATF around 90,000 km, and added a large transmission cooler at the same time. Vehicle started towing duty shortly before this happened. I've changed the ATF / filter once again at 180,000 km with Amsoil, and the last time was around 240,000 km. The van now has over 300,000 km, runs and shifts perfectly, has had no internal engine or transmission work, and does very frequently pull heavy loads (right up to it's maximum trailer weight rating and/or cargo rating). In the summer, it pulls a trailer almost every weekend, but it is seldom used in the winter. I also load it up inside with heavy household items (drywall, paving stones, gravel bags, etc) in excess of 1,500 lbs. No issues. Largest trailer load that was towed on multiple occasions was up around 4,000 lbs. Still no issues. This van was directly involved in building / completely renovating 2 houses over 4 years. I'm sure the van will rot from rust prior to me having any tranny issues!

My parent's current cars are too new to really glean anything from longevity, but I have changed each of their transmission fluids with factory (Mercedes-Benz approved) synthetic fluids both at 60,000 km. They are now coming up onto 120,000 km, where I will again change the fluid and filters for them.

My wife's car is a 2006 Mazda 6. These FNR transmissions are not known for longevity if they are not maintained, and with a suitable fluid. We bought the car used back in 2012 with 90,000 km on it. No tranny service before that. Fluid was pitch black and shifts were not smooth. I changed several times since then with Amsoil ATF, and did a pan drop / filter change once. Shifts are much better now. I will be adding a cooler to this vehicle as we will start towing a small trailer with it next year. It is currently at 140,000 km with no issues other than a slightly firm 1-2 shift when the tranny is cold (first couple of shifts in the morning). This seems to be common to the 2006 model year, and is likely due to bad programming. No other issues (yet)!

Both my current vehicle and previous vehicle (daily drivers) have had manual transmissions, so I can't offer any other experiences past the ones above regarding automatics, but so far, I think I've had all good experiences with the auto's in my family. I think maintenance is key, and keeping the fluid temperatures in check if the vehicle will be used for any kind of towing / hauling, or if factory cooling is marginal in the first place. Transmission fluid does not have to be as hot as engine oil, nor should it be.
 
Originally Posted By: RPMster
The service life of automatic transmissions can vary due to several factors. The factors that seem the most significant include operating conditions, factory defects, and maintenance histories.

Some vehicles can run over 200,000 miles with the original transmission and zero maintenance, while others can be serviced regularly using factory spec ATF and still have transmission failure by 150,000 miles or sooner.

There has been debate for years over "multi-vehicle" aftermarket fluids being better/worse/equal compared to factory spec fluids available at dealers. This argument will most certainly continue for many years to come.

Please share your personal experience with automatic transmission longevity in your current and past vehicles.

How were they used: Easy freeway commutes? City driving? Heavy loads?

How did you maintain your automatic transmission: OCI, drain/fill or flush, serviceable filter, factory fluid or multi-vehicle fluid, DIY or dealer/shop, etc?

Did the transmission have any factory defects (either non-typical defects, or well known defects that were common to that vehicle model)?

Any other details that might be relevant?


We currently have almost 150k miles on an '03 Accord V-6 and the automatic transmission still shifts like new. I've changed the fluid every 30k miles since new, which is radically more often than Honda suggests. At first I slavishly kept to Honda ATF-Z1, but then switched to Castrol Import Multi-Vehicle. No troubles yet.

I'm not at all bought into the ultra high change intervals most auto makers now spec for transmission fluids.
 
Ex-wife's 2003 Mercury Marauder. Just did an oil change and ATF drain & fill this morning. Installed a drain plug on the pan when we bought it with 87,000 miles in 2007. Now at 195,000 miles and the transmission is still like new thanks to regular fluid changes.

1985 Chevrolet Citation bought new (now long gone). Sold it with 221,000 miles and never touched the transaxle other than to check the level once in a while. (Didn't know any better back then)

Both sides of the coin...
 
My 2 cents.

Qualifiers:
#1 Dirt intrusion is always a risk when opening up the transmission so less is more in this case.

#2 With long service intervals you may open up the transmission only 3-4 times so there's no reason to use anything but OE fluid.

The ZF gearbox is relatively bulletproof on the 100k lifetime fill but ZF has a severe service interval of 45k-60k miles.

I did my 335d at 55k miles because my car put out 425ft/lb at 1500 rpms and I knew it would help with re-sale.

I used ZF (OE) fluid.
 
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Wife's previous car was a 2008 MB C300 4matic. It was purchased in 2010 as a CPO vehicle with 20K miles on the clock.

Maintenance schedule called for ATF replacement every 39K miles, and that's what was done, by the dealer.

At 60K miles, the car needed a new transmission. Apparently, the trans itself was fine, but the AWD transfer case failed, and since it is integrated with the transmission, the whole transmission had to be replaced. From what I've seen reported on various MB forums, these 4matic transfer cases are known to fail prematurely in those model years.
 
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