Transmission fluid question
09-28-2016, 12:08 AM
#21
What trans? 5HP? 6HP? 8HP? Without that info this poll is useless. That's like having a poll for engine failure but including all kinds of engines. Also the poll was started in 2006. The data is useless.
Let's go another route. Have you ever rebuilt an automatic transmission? Do you understand how they work? A fluid change cannot break anything that isn't already broken. All it does is swap out the degraded fluid for fluid in perfect condition. This allows the transmission to operate as efficiently as possible.
Your C6 most likely has a 6HP. They are pretty reliable and the 3.2 isn't putting out much power so it's not as if you are working the trans very hard. However my C5 has a 5HP which is prone to failure. It's also a 2.7t which is a pretty high output motor. Same situation with my D4. It's all about return on investment. If a fluid change helps my transmissions last longer it's worth it.
Let's go another route. Have you ever rebuilt an automatic transmission? Do you understand how they work? A fluid change cannot break anything that isn't already broken. All it does is swap out the degraded fluid for fluid in perfect condition. This allows the transmission to operate as efficiently as possible.
Your C6 most likely has a 6HP. They are pretty reliable and the 3.2 isn't putting out much power so it's not as if you are working the trans very hard. However my C5 has a 5HP which is prone to failure. It's also a 2.7t which is a pretty high output motor. Same situation with my D4. It's all about return on investment. If a fluid change helps my transmissions last longer it's worth it.
I am not saying a fluid change would break something. I am saying that if the transmission on the car is not designed to be serviced, the fluid change would likely be done wrong and it would be easy for outside impurities to get in and compromise the transmission. Just describe how you change your fluid and you'll see by yourself. People are not even sure how much fluid to put in and it can't even be called a fluid change as you cannot drain the whole fluid. You just mix new fluid with old fluid over and over with the risk of letting air, humidity or impurities get in.
Like I said earlier, I am not basing any of my arguments on the C5. Mine is a manual. I'm basing them on the research I've done on my C6 which is automatic.
Last edited by kelisko; 09-28-2016 at 12:10 AM.
09-28-2016, 11:36 AM
#22
AudiWorld Super User
The transmission has a vent. Air and humidity can and do get in. As far as impurities go unless you're adding a large quantity of some strange liquid you can't hurt anything there either.
You also cant get all of the oil out when you change oil in your car. However you still change it. Granted there is a reasonable quantity left in the torque converter when you drain the transmission but that's why you either change it twice or change it often. Just because some residual fluid remains doesn't really hurt anything.
As far as that poll goes it is 100% useless. No logical or scientific conclusions can be drawn from that data. The only idea I get from it is how not to set up a poll on transmission reliability. A similar poll today would be equally useless. But a properly set up poll would absolutely show an improvement in transmission reliability. You are correct and manufacturers have improved their products. Also newer cars have much lower mileage and therefore there isn't enough data on long term reliability. Many people like myself hedge their bets and give their transmission fresh fluid to help it live longer. The ZF 8hp in my A8 for example is also used by Chrysler in their high HP cars and in their 1/2 ton diesel trucks. People are already changing the fluid and filter in them and are seeing a significant amount of fluid degradation. This tends to be people who drive their cars hard and tow with their trucks. In other words activities that stress the transmission. I certainly don't tow with my A8 but I do enjoy the power of the 4.0t and use it often. Therefore I'm going to help my transmission live a little longer.
You also cant get all of the oil out when you change oil in your car. However you still change it. Granted there is a reasonable quantity left in the torque converter when you drain the transmission but that's why you either change it twice or change it often. Just because some residual fluid remains doesn't really hurt anything.
As far as that poll goes it is 100% useless. No logical or scientific conclusions can be drawn from that data. The only idea I get from it is how not to set up a poll on transmission reliability. A similar poll today would be equally useless. But a properly set up poll would absolutely show an improvement in transmission reliability. You are correct and manufacturers have improved their products. Also newer cars have much lower mileage and therefore there isn't enough data on long term reliability. Many people like myself hedge their bets and give their transmission fresh fluid to help it live longer. The ZF 8hp in my A8 for example is also used by Chrysler in their high HP cars and in their 1/2 ton diesel trucks. People are already changing the fluid and filter in them and are seeing a significant amount of fluid degradation. This tends to be people who drive their cars hard and tow with their trucks. In other words activities that stress the transmission. I certainly don't tow with my A8 but I do enjoy the power of the 4.0t and use it often. Therefore I'm going to help my transmission live a little longer.
09-29-2016, 02:05 AM
#23
Until we get accurate information, to each their own then 
To come back to the topic, Victor Rodriguez, at 92K miles, it "might" be too late to do an ATF fluid change for your A5 if it wasn't done around 50K miles. From what I've read online, it is better to let it alone at that point as transmissions tend to malfunction or fail after a "first" fluid change at high mileage.
To come back to the topic, Victor Rodriguez, at 92K miles, it "might" be too late to do an ATF fluid change for your A5 if it wasn't done around 50K miles. From what I've read online, it is better to let it alone at that point as transmissions tend to malfunction or fail after a "first" fluid change at high mileage.
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