question about automatic transmission fluid changes

[Lifer]

is there an ATF filter?
do you change it everytime you drain the ATF?


is it true that if you have never changed the ATF and you have high miles, that should just leave it alone otherwise if you try changing it, it'll harm the tranny?

 

[LS20]

no filters.. and false

 

[MrBond]

Originally posted by: LS20
no filters.. and false

My oldsmobile (automatic) has a transmission filter.

It was changed about 25,000 miles ago, it's not a regular maintence thing like oil/filter, plus it's a giant pain in the ass to remove and change.

It probably says in your car's manual the reccomended changing frequency.

 

[FritzTheCat]

Yes there is an automatic transmission filter. It's attached to the bottom of the valve body. You access it by removeing the transmission pan. It should be changed every time you change the fluid. As you have to drop the pan to change the fluid, you change the filter at the same time.

Most oil change shops will not change the tranny fluid if it's been a real long time since the last change, for fear of something going wrong with the trans and they get blamed.

 

[tcsenter]

Most transmissions have a filter of some type, even if only a screen. It is advisable to replace it every time you change the fluid, but that is only required about every 50,000~100,000 miles. Some manufacturers claim it should never be required.

is it true that if you have never changed the ATF and you have high miles, that should just leave it alone otherwise if you try changing it, it'll harm the tranny?

This is highly debatable and there is no solid 'proof' either way, sorta like does synthetic oil make your engine 'last longer'. Actually I take that back, there is a lot evidence that synthetic oil does not make your engine 'last longer' and no evidence that it does except for manufacturer marketing and anecdotal evidence.

The idea is not that it will 'harm' the transmission, but will cause an already failing transmission to become symptomatic sooner and thus require rebuilding/overhauling sooner.

 

[Eli]

Originally posted by: tcsenter
Most transmissions have a filter of some type, even if only a screen. It is advisable to replace it every time you change the fluid, but that is only required about every 50,000~100,000 miles. Some manufacturers claim it should never be required.

is it true that if you have never changed the ATF and you have high miles, that should just leave it alone otherwise if you try changing it, it'll harm the tranny?

This is highly debatable and there is no solid 'proof' either way, sorta like does synthetic oil make your engine 'last longer'. Actually I take that back, there is a lot evidence that synthetic oil does not make your engine 'last longer' and no evidence that it does except for manufacturer marketing and anecdotal evidence.

The idea is not that it will 'harm' the transmission, but will cause an already failing transmission to become symptomatic sooner and thus require rebuilding/overhauling sooner.

Uh......

What evidence is there that synthetic oil doesen't make your engine last longer? It is not anecdotal, it's a fact, all else being equal. All you have to do is look at the specs of the different oils.

That said, the oil you use doesen't make an ounce of difference if your oil filter is a piece of garbage. Even the best oil on the planet is rendered useless if it has solid particles in it. Your air filter is important, too.

Use whatever oil you want. If you get an AMSOil Bypass oil filter, your car will fall apart around your engine.

 

[FracturedSoul]

Yeah, synthetic oil doesn't make your engine last longer

That's why most racers use synthetic now over regular oil, it is great for reducing oil temps and keeps things nicely lubricated. The only thing that sucks ass about synthetic is that it is a bitch to sweep up.

 

[iamwiz82]

every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

 

[FracturedSoul]

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

What about a high mileage toilet? Still no flushing?

 

[iamwiz82]

Originally posted by: FracturedSoul

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

What about a high mileage toilet? Still no flushing?

stick your head in and try

 

[Lifer]

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

what's the difference between a flush and a change?

 

[iamwiz82]

Originally posted by: Lifer

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

what's the difference between a flush and a change?

a power flush is when they put a high pressure pump to pump out all the old fluid and then it is replaced by new fluid. The problem is that it tends to knock debris from places where it had accumulated to more damaging spots, like the valve body.

 

[FracturedSoul]

Originally posted by: iamwiz82

Originally posted by: FracturedSoul

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

What about a high mileage toilet? Still no flushing?

stick your head in and try

No thanks, since it is your idea I'll let you go ahead and try first!

 

[Eli]

Originally posted by: iamwiz82

Originally posted by: Lifer

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

what's the difference between a flush and a change?

a power flush is when they put a high pressure pump to pump out all the old fluid and then it is replaced by new fluid. The problem is that it tends to knock debris from places where it had accumulated to more damaging spots, like the valve body.

Pretty much.

With a flush, they'll fill the tranny up with a cleaning fluid, and then pump it back out before refilling with ATF.

 

[tcsenter]

What evidence is there that synthetic oil doesen't make your engine last longer? It is not anecdotal, it's a fact, all else being equal. All you have to do is look at the specs of the different oils.

Why has there never been a single independent (non-oil company funded/sponsored) study which has found that engines "last longer" using synthetic oil? Not a single one. A four-ball wear test is not an "engine".

Consumer Reports, however, took several dozen remanufactured engines, disassembled them, measured and documented all critical moving parts using a micrometer, reassembled them, installed them in taxi cabs, then used a particular brand/weight of oil in each engine; ranging from the cheapest 'white label' conventional oil to Mobil 1. It reserved some of the engines to test different drainage intervals; ranging from the 'popular' 3,000 mile to over 6,000 miles. They disassembled each engine at 50,000 mile intervals and micrometered the critical moving parts again, then documented the delta.

Absolutely no difference whatsoever found between conventional and synthetic oils. Engines did not "last longer", nor did they have measurably "less wear".

Ok, your turn. I will not be holding my breath waiting for this non-manufacturer funded/sponsored study because none exist.

Use whatever oil you want. If you get an AMSOil Bypass oil filter, your car will fall apart around your engine.

Yeah right, peddle it somewhere else. This former Amsoil dealer isn't buying.

 

[toph99]

Originally posted by: tcsenter

What evidence is there that synthetic oil doesen't make your engine last longer? It is not anecdotal, it's a fact, all else being equal. All you have to do is look at the specs of the different oils.

Why has there never been a single independent (non-oil company funded/sponsored) study which has found that engines "last longer" using synthetic oil? Not a single one. A four-ball wear test is not an "engine".

Consumer Reports, however, took several dozen remanufactured engines, disassembled them, measured and documented all critical moving parts using a micrometer, reassembled them, installed them in taxi cabs, then used a particular brand/weight of oil in each engine; ranging from the cheapest 'white label' conventional oil to Mobil 1. It reserved some of the engines to test different drainage intervals; ranging from the 'popular' 3,000 mile to over 6,000 miles. They disassembled each engine at 50,000 mile intervals and micrometered the critical moving parts again, then documented the delta.

Absolutely no difference whatsoever found between conventional and synthetic oils. Engines did not "last longer", nor did they have measurably "less wear".

Ok, your turn. I will not be holding my breath waiting for this non-manufacturer funded/sponsored study because none exist.

Use whatever oil you want. If you get an AMSOil Bypass oil filter, your car will fall apart around your engine.

Yeah right, peddle it somewhere else. This former Amsoil dealer isn't buying.

taxis idle all day, which means that their oil is always at operating temp, therefore protecting the best. Synthetics outperform dino in the most important area - cold flow. Synthetic will flow much faster on startup than dino will, thus protecting more for the average user, as the most damage is done on startup. This is not an issue for a car that is running all day and rarely has cold starts. This is an issue for most people who do short trips, start their cars many times in a day etc. and for those of us who deal with -30C weather where 5W30 dino turns almost into jelly, synthetic will still pour.


now for Lifer's post...
most cars have an ATF filter, i have yet to see one that doesn't but that doesn't mean they don't exist.
The problem with changing the ATF at high mileage is if it's brown/black and smells burnt. This means most of the clutch material is in the fluid itself, and if the tranny is on it's last legs and you remove that clutch material and replace it with fresh fluid, there won't be enough friction for it to work properly. That and new fluid has more detergent than the old ones, which can break loose deposits and wreak havoc on the internals. If the fluid looks ok still, then changing it shouldn't be a problem. Make sure you drain the torque converter though.

 

[tcsenter]

taxis idle all day, which means that their oil is always at operating temp, therefore protecting the best. Synthetics outperform dino in the most important area - cold flow. Synthetic will flow much faster on startup than dino will, thus protecting more for the average user, as the most damage is done on startup. This is not an issue for a car that is running all day and rarely has cold starts.

So true, and if we were discussing what's best for diesel engines based in Alaska or Northern Minnesota in January, I'd recommend synthetic all the way.

Of course, they have these things called "block heaters" which are very popular these days with diesel fleets. You plug them in and they keep your engine oil at readily pumpable temps, so the advantage of synthetic's sub-freezing performance disappears. Oh well, so much for that argument....

 

[toph99]

Some people don't have outlets for block heaters in their GASOLINE engines and as far as i know, block heaters only heat the coolant, unless you have an oil heater. Sure, some heat will make its way to the oil but not enough to make a difference.

Also with more and more engines being an overhead cam design, getting oil to the top of the engine is very important, which, again, synthetic will outperform any dino oil. I know i hated every cold winter day when i had to start my poor 4.6, because i had a bottle of 5w30 outside and the stuff would barely move when i turned it upside down.

For someone who wants the best protection for their engine, synthetic is the way to go, no if's and's or but's. This isn't to say that dino is horrible and everyone should use synthetic, because many people do not drive in circumstances that warrant it's use, but syn. is better.

 

[tcsenter]

Some people don't have outlets for block heaters in their GASOLINE engines and as far as i know, block heaters only heat the coolant, unless you have an oil heater. Sure, some heat will make its way to the oil but not enough to make a difference.

The block heaters we used in our fleet at a major regional auto parts distribution center heated the coolant and oil.

Also with more and more engines being an overhead cam design, getting oil to the top of the engine is very important, which, again, synthetic will outperform any dino oil. I know i hated every cold winter day when i had to start my poor 4.6, because i had a bottle of 5w30 outside and the stuff would barely move when i turned it upside down.

True, in weather approaching or exceeding freezing temperatures, synthetic can 'outflow' conventional. In temperature/environmental extremes, synthetic can help keep engine temperatures a few degrees lower.

And yet not a single study has proven this translates into "longer lasting engines" or "reduced engine wear". Not one.

For someone who wants the best protection for their engine, synthetic is the way to go, no if's and's or but's. This isn't to say that dino is horrible and everyone should use synthetic, because many people do not drive in circumstances that warrant it's use, but syn. is better.

And yet not a single study has proven this translates into "longer lasting engines" or "reduced engine wear". Not one.

 

[toph99]

the fact that it flows faster at startup, and that most wear occurs on startup, means that synthetic will protect and engine better than dino given the same circumstances. The problem is, there are other variables. Preventetive maintainence by the owner, oil change intervals, quality of oil filter etc. all play a factor, so it's not possible to test. When using fleet vehicles such as police and taxis, because they are not driven like normal vehicles they can not be used as a judgement on how the product will perform for the average consumer.

most people don't have block heaters that heat the oil I also did not use my block heater once(didn't know it had one til i blasted the plug out of it's hiding space while washing the car) all winter, and it was a damn cold one this year.

 

[tcsenter]

the fact that it flows faster at startup, and that most wear occurs on startup, means that synthetic will protect and engine better than dino given the same circumstances. The problem is, there are other variables. Preventetive maintainence by the owner, oil change intervals, quality of oil filter etc. all play a factor, so it's not possible to test.

Oh its certainly possible to test. What is proving difficult (or nearly impossible) is to measure a benefit.

Its certainly possible to take a number of engines, have them remanufactured to 'balanced and blueprinted' specifications, all moving interfaces micrometered exactingly, then each engine installed in a car and driven in a way which reflects 'typical use', all maintenance performed at planned intervals (within an acceptable margin), then each engine disassembled at planned intervals (within an acceptable margin), including periodic oil analysis to measure all characteristics of the oil (including metal wear), remicrometer all critical parts and inspect all interfacing surfaces.

This is impossible? Why?

When using fleet vehicles such as police and taxis, because they are not driven like normal vehicles they can not be used as a judgement on how the product will perform for the average consumer.

Ok, so you agree that synthetic is a waste in fleets, which is a big area that synthetic marketers target and claim to be seeing a benefit.

How can that be since you've just agreed that synthetics are a waste in fleets?

 

[toph99]

Its certainly possible to take a number of engines, have them remanufactured to 'balanced and blueprinted' specifications, all moving interfaces micrometered exactingly, then each engine installed in a car and driven in a way which reflects 'typical use', all maintenance performed at planned intervals (within an acceptable margin), then each engine disassembled at planned intervals (within an acceptable margin), including periodic oil analysis to measure all characteristics of the oil (including metal wear), remicrometer all critical parts and inspect all interfacing surfaces.

This is impossible? Why?

This is not possible because for accuracy each car would have to be started, stopped, driven the same way and in the same conditions. It may be possible to do in a lab, but would be very time consuming to synthesise the life of an engine on a dyno.

Ok, so you agree that synthetic is a waste in fleets, which is a big area that synthetic marketers target and claim to be seeing a benefit.

How can that be since you've just agreed that synthetics are a waste in fleets?

Any company is going to market their product towards the area that will make them the most money, and in this area, fleets use immense amounts of oil. Synthetics make their point with extended drain intervals, which is appealing because if you have 700 cars, allowing them to go at least twice as long between oil changes will save loads in oil, and just as much in lost downtime. With a filter change and an oil analysis, it is possible to go upwards of 12 000 miles between oil changes, which can mean a lot of extra money for fleets. Dino oil will protect just as well in a fleet vehicle as synthetic will, just it has to be changed more often on average.

 

[Pacfanweb]

Originally posted by: toph99
Some people don't have outlets for block heaters in their GASOLINE engines and as far as i know, block heaters only heat the coolant, unless you have an oil heater. Sure, some heat will make its way to the oil but not enough to make a difference.

Also with more and more engines being an overhead cam design, getting oil to the top of the engine is very important, which, again, synthetic will outperform any dino oil. I know i hated every cold winter day when i had to start my poor 4.6, because i had a bottle of 5w30 outside and the stuff would barely move when i turned it upside down.

For someone who wants the best protection for their engine, synthetic is the way to go, no if's and's or but's. This isn't to say that dino is horrible and everyone should use synthetic, because many people do not drive in circumstances that warrant it's use, but syn. is better.

What was the temp. that 5w30 wouldn't flow? Negative what? That's a load of horse crap. You can turn a can of 5w30 upside down at 20 degrees and it'll flow out like water. For extremely cold temps, that's what they make block heaters for.....and BTW, if a block heater is heating the coolant....it's also heating up the oil.

 

[Pacfanweb]

With a filter change and an oil analysis, it is possible to go upwards of 12 000 miles between oil changes, which can mean a lot of extra money for fleets. Dino oil will protect just as well in a fleet vehicle as synthetic will, just it has to be changed more often on average.

12,000 miles on an oil change? That's 2 dino oil changes at the 5k intervals recommended today.....no savings there. If you change it every 3k, there's still no significant savings. You still have to change the filter for the synthetic to be effective, so you really save nothing at all.

 

[Pacfanweb]

Originally posted by: iamwiz82

Originally posted by: Lifer

Originally posted by: iamwiz82
every automatic transmission i have seen has had a filter. Not changing your fluid on a high mileage transmission is false. They recommend you do not FLUSH your high mileage tranny, however.

what's the difference between a flush and a change?

a power flush is when they put a high pressure pump to pump out all the old fluid and then it is replaced by new fluid. The problem is that it tends to knock debris from places where it had accumulated to more damaging spots, like the valve body.

All the trans flush machines I've seen simply use the pressure from the transmission's own pump to first circulate some cleaner in the old fluid, then replace the old with new.

The flush is FAR, FAR superior to dropping the pan and changing the filter or screen. When you change tranny fluid by dropping the pan, and I'll use a Taurus for example, you drain out anywhere from 4-6 qts of fluid. The average trans holds anywhere from 12-16 quarts. So you have 4-6 new qts. in with your 8-12 qts of old, dirty fluid. Not much help there.
On some cars/trucks, you can drain the torque converter, which is where most of the fluid is. Vehicles that have this option are really the only ones that I'd consider changing the fluid the "old fashioned way", but really, the only reason to ever change the fluid this way is if you need to remove the pan anyway, such as to fix a leak.