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Discussion Starter · #1 ·
I recently purchased a 2001 Aztek it was a great find only 76k, everything over the years has been changed and kept up the only thing is transmission fluid. My transmission fluid is still red the car shifts and runs great I did ask my mechanic and it is "dirty" and he recommends changing it. I know some people say older transmissions have issues after change and what not so should I change it or not ? If so should I have it flushed ? All help is appreciated!
 

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My own amateur opinion is I'd probably change it, but no way would I flush it at this point.

No fresh ATF...is the OE stuff 150K spec or something like that? That would have some bearing on my decision.
 

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Discussion Starter · #3 ·
The manual states that you can go to 100k under non severe conditions or change at 50k under severe conditions. I spoke to my local Buick dealer and their service guy said to change it. From reading on here and a few other places a flush is a no no correct ? Just drop the pan and change the filter and fluid right ?
 

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Since you don't really know what sort of "conditions" the vehicle was driven in previously, simply err on the side of caution and change it now. I personally change mine every 50k; I would suggest simply dropping the pan and changing the filter/drain without the flush.
 
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First question, are you having any transmission trouble?

If no,

I would change all of the transmission fluid.

The problem with a pan drop and filter change is you only change about 1/3 of the fluid in the transmission. Then the new fluid is busy cleaning the old fluid. That is when the soluble material falls out of suspension and can clog stuff up. In a pan drop you can not drain the torque convertor.

I recommend doing a flush with a quality product. BG Products are the industries best, period. They use a cleaner to clean the gum and varnish build up inside the transmission and torque convertor. The cleaner also safely cleans the filter (which is a misnomer-there is no "filter"- it is actually a particulate screen) torque convertor, and the valve body. The BG machine allows the transmission front pump to push out the old fluid through a cooler line and that pressure pushes the new fluid into the transmission, by of an internal bladder in the machine. This is done 1,000's of time a day around the country with no issues.

I have seen way more issues with the pan drop and filter change at high mileage, and very very few from the flush.

If there is an existing problem with the transmission, neither pan drop nor flush will fix-broke.
 

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Always follow the owner's manual. That said, that doesn't seem like you have reached the amount of miles where the fluid starts holding the transmission together without ever having been changed. I do not think you would be adversely affected by changing it.
 

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I'd go with Jim Injun Ear here. :cool:
 

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First question, are you having any transmission trouble?

If no,

I would change all of the transmission fluid.

The problem with a pan drop and filter change is you only change about 1/3 of the fluid in the transmission. Then the new fluid is busy cleaning the old fluid. That is when the soluble material falls out of suspension and can clog stuff up. In a pan drop you can not drain the torque convertor.

I recommend doing a flush with a quality product. BG Products are the industries best, period. They use a cleaner to clean the gum and varnish build up inside the transmission and torque convertor. The cleaner also safely cleans the filter (which is a misnomer-there is no "filter"- it is actually a particulate screen) torque convertor, and the valve body. The BG machine allows the transmission front pump to push out the old fluid through a cooler line and that pressure pushes the new fluid into the transmission, by of an internal bladder in the machine. This is done 1,000's of time a day around the country with no issues.

I have seen way more issues with the pan drop and filter change at high mileage, and very very few from the flush.

If there is an existing problem with the transmission, neither pan drop nor flush will fix-broke.

GM does NOT recommend flushing the transmission fluid. If you read the owner's manual on many GM cars - it states to change the fluid and filter (in some GM transmissions the filter can not be changed without removing the transmission and doing a complete overhaul).

GM has issued a TSB that advises against engine and transmission flushes, and it states that anything used in a transmission other that GM approved fluid is considered a contaminant.

Dealers love BG flushes as they are much easier and they can charge a higher amount for the service with less labor cost.

I would follow the recommendation of GM - not an aftermarket company.
 

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I have mixed feelings about the BG flush, most of the time it works well, and indeed saved my son's '99 Blazer (now mine) from a suggested valve body change. If it was under 50K I'd say go ahead. At this mileage I would go the extra step of dropping the pan after the flush and replacing the filter. This also lets you make sure nothing gets left in the pan. 4t60's do have a filter, not just a screen. The lower pan gasket and filter come in a kit. Yours could have a reuseable gasket, if so it will be thick and made of rubber. You can see that from the side, if so you can just buy the filter. This way you get the TC flushed out and make sure the filter isn't plugged by flushed out gunk.

Nice find. I'd take one of those in a heartbeat. What others think of my car's styling has never mattered much to me, and they are oh so practical. The obvious other concern is intake gaskets, not likely they haven't been replaced, but I'd keep an eye on them. Not a bad job to do yourself if necessary.
 

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GM does NOT recommend flushing the transmission fluid. If you read the owner's manual on many GM cars - it states to change the fluid and filter (in some GM transmissions the filter can not be changed without removing the transmission and doing a complete overhaul).

GM has issued a TSB that advises against engine and transmission flushes, and it states that anything used in a transmission other that GM approved fluid is considered a contaminant.

Dealers love BG flushes as they are much easier and they can charge a higher amount for the service with less labor cost.

I would follow the recommendation of GM - not an aftermarket company.
Transmission fluid is oil.

White 99, how often do you change your engine oil?

GM maintenance schedule lists lots of things that many people do not follow, and over maintenance their vehicles.

Is it acceptable to maintain your vehicle, to a greater level than the maintenance schedule states?

What is wrong with that?

But you fail to respond to my comments about changing only 1/3 of the fluid, would you change 1/3 of your engine oil?

GM maintenance schedule used to require oil changes based on an oil life index monitor system that allowed some vehicles to go as long as 18,000+ miles before the first oil change. They recalled that system and recalibrated it 3 years later, and the recalibration put a 7,500 max mileage. But, to this day, there are customers who have not had the recall performed.

Are you aware of the 2014 & 2015 maintenance schedule recommendations for transmission, differential fluid, brake fluid, or clutch slave cylinder fluid?

Your statement about fluid other than GM Approved fluid is a contaminant is facetious. There are plenty of fluids out there that far exceed the ASTM testing of GM DEX VI or many other GM fluids. The reason GM makes these statements are totally driven by revenue. GM sells these fluids, and wants customers to buy from GM, and make false accusations about everything but GM. There are inferior fluids on the market, but to claim everything except GM is a contaminant is incorrect.

The GM TSB you refer to does not state your "contaminant" claim posted above. But it does advise against engine flushes. GM issues a very similar bulletin every year or so about aftermarket services. Mainly to defend the sales of their products, trying to lock out the competition.
#04-06-01-029G - (Sep 27, 2012)
Document ID: 2913603

Did you ever think that the transmission fluid exchange costs more than a pan drop, may be because instead of replacing 4 quarts of fluid it may be using 12, 14, or more quarts of fluid. And before you ask why, let me ask you a question, do you wash a coffee cup with 8oz of water?

BTW, not removing the trans pan, minimizes the opportunity for over tightening of the pan bolts resulting in a leak (anyone ever experienced that?).

:)
 

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Transmission fluid is oil.

White 99, how often do you change your engine oil?

GM maintenance schedule lists lots of things that many people do not follow, and over maintenance their vehicles.

Is it acceptable to maintain your vehicle, to a greater level than the maintenance schedule states?

What is wrong with that?

But you fail to respond to my comments about changing only 1/3 of the fluid, would you change 1/3 of your engine oil?

GM maintenance schedule used to require oil changes based on an oil life index monitor system that allowed some vehicles to go as long as 18,000+ miles before the first oil change. They recalled that system and recalibrated it 3 years later, and the recalibration put a 7,500 max mileage. But, to this day, there are customers who have not had the recall performed.

Are you aware of the 2014 & 2015 maintenance schedule recommendations for transmission, differential fluid, brake fluid, or clutch slave cylinder fluid?

Your statement about fluid other than GM Approved fluid is a contaminant is facetious. There are plenty of fluids out there that far exceed the ASTM testing of GM DEX VI or many other GM fluids. The reason GM makes these statements are totally driven by revenue. GM sells these fluids, and wants customers to buy from GM, and make false accusations about everything but GM. There are inferior fluids on the market, but to claim everything except GM is a contaminant is incorrect.

The GM TSB you refer to does not state your "contaminant" claim posted above. But it does advise against engine flushes. GM issues a very similar bulletin every year or so about aftermarket services. Mainly to defend the sales of their products, trying to lock out the competition.
#04-06-01-029G - (Sep 27, 2012)
Document ID: 2913603

Did you ever think that the transmission fluid exchange costs more than a pan drop, may be because instead of replacing 4 quarts of fluid it may be using 12, 14, or more quarts of fluid. And before you ask why, let me ask you a question, do you wash a coffee cup with 8oz of water?

BTW, not removing the trans pan, minimizes the opportunity for over tightening of the pan bolts resulting in a leak (anyone ever experienced that?).

:)
First dexron VI is not a petroleum product, it's synthetic. Not changing the filter is wasting money on a flush. I've owned my own transmission shop for 34 years, it's a well known fact flushing disturbs the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged. If you remove the filter open it up you will get the true story on the condition of your transmission, if it's clean it was well taken care of, if you have copper washers in it you have a planet carrier coming apart this tells you that an over haul is in your future and you can plan for it. Cutting corners doesn't help anyone but the guy that owns the flushing machine, do a proper service you won't be sorry.:yup:
 

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First dexron VI is not a petroleum product, it's synthetic. Not changing the filter is wasting money on a flush. I've owned my own transmission shop for 34 years, it's a well known fact flushing disturbs the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged. If you remove the filter open it up you will get the true story on the condition of your transmission, if it's clean it was well taken care of, if you have copper washers in it you have a planet carrier coming apart this tells you that an over haul is in your future and you can plan for it. Cutting corners doesn't help anyone but the guy that owns the flushing machine, do a proper service you won't be sorry.:yup:
Let me ask you a question, for your 34 years of experience, does fluid failure lead to transmission failure?

If you are having a transmission issue, pulling the pan to analyze the pan debris is the right thing to do. But if you are just looking to replace the fluid, a total fluid exchange is better than just replacing 1/3 of the fluid, would you agree? Do you replace the engine filter and 1/3rd of it's oil? Do you pull the oil pan on the engine when you change its oil and filter (which are pleated paper filters)?

"Well known fact"??? State your source?
Based on what you say, why does the normal transmission operation not disturb "the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged"?
Why would a fluid exchange service disturb, everything?

Do know how the BG trans machines work?
1,000's of BG transmission fluid exchanges are performed every day nationally.

No where did I suggest not using DEXVI (or comparable fluid), or a non-synthetic fluid. Just using a cleaner, replacing all of the fluid, and a conditioner.

Do you understand what a synthetic fluid is? Based upon the above statement, I wonder.

In your transmission shop, what % of recent vehicles have an screen for a filter vs paper?

Here is a TSB from Quaker State, a major producer of transmission fluid.
“When a pan-drop transmission service is performed, a large portion of the old fluid cannot be drained. Oxidation products, while soluble in the old fluid, are insoluble in the new fluid and fall out as sludge.
This results in plugged oil passages and screens, and caused control values to stick.”
-Quaker State
This supports replacing all of the fluid instead of just 1/3rd.

What you suggest is a proper service for a transmission with an issue, which I would NEVER consider exchanging the fluid on. A fluid exchange will not fix a broken transmission.

My point is on a vehicle that you are wanting to maintain for a long time, replacing all of the fluid in a service is optimal, vs 1/3rd of the fluid.

Would you agree with me, that the first part of component failure is fluid failure?
 

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This sentence makes me laugh. Where do you think the chemicals that make a synthetic lubricant come from?
Non petroleum means just that......... The chemicals are man made and not purified crude. Also has 6 times the detergents and is E.P. rated not to mention will not burn or turn to sludge. You really should get out more.........makes me laugh to know there's uninformed experts on this site.
 

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Let me ask you a question, for your 34 years of experience, does fluid failure lead to transmission failure?

If you are having a transmission issue, pulling the pan to analyze the pan debris is the right thing to do. But if you are just looking to replace the fluid, a total fluid exchange is better than just replacing 1/3 of the fluid, would you agree? Do you replace the engine filter and 1/3rd of it's oil? Do you pull the oil pan on the engine when you change its oil and filter (which are pleated paper filters)?

"Well known fact"??? State your source?
Based on what you say, why does the normal transmission operation not disturb "the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged"?
Why would a fluid exchange service disturb, everything?

Do know how the BG trans machines work?
1,000's of BG transmission fluid exchanges are performed every day nationally.

No where did I suggest not using DEXVI (or comparable fluid), or a non-synthetic fluid. Just using a cleaner, replacing all of the fluid, and a conditioner.

Do you understand what a synthetic fluid is? Based upon the above statement, I wonder.

In your transmission shop, what % of recent vehicles have an screen for a filter vs paper?

Here is a TSB from Quaker State, a major producer of transmission fluid.
“When a pan-drop transmission service is performed, a large portion of the old fluid cannot be drained. Oxidation products, while soluble in the old fluid, are insoluble in the new fluid and fall out as sludge.
This results in plugged oil passages and screens, and caused control values to stick.”
-Quaker State
This supports replacing all of the fluid instead of just 1/3rd.

What you suggest is a proper service for a transmission with an issue, which I would NEVER consider exchanging the fluid on. A fluid exchange will not fix a broken transmission.

My point is on a vehicle that you are wanting to maintain for a long time, replacing all of the fluid in a service is optimal, vs 1/3rd of the fluid.

Would you agree with me, that the first part of component failure is fluid failure?
If you have fluid failure in a modern automatic transmission you deserve everything you get. If you cannot service the unit every 2 years as is recommended by ATSG then the failure is on you. No, fluid failure is only see on units that never get serviced, I rebuild many that get flushed by garages that know nothing about the unit they're flushing and when it won't shift or codes come up it's towed to my shop. ATSG recommends never to flush any unit period. They are my source for training, updates, modifications and general information, so my opinion comes from experience not what some company says to sell there products.
 

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Jim paper has never been used as a filter medium even on Allison and 45rfe return filters, they use foam. Brass or plastic screen are the standard, Chrysler used cotton up until recently. Not to mention all the screens in the valve body and pump on today's units.
 

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If you have fluid failure in a modern automatic transmission you deserve everything you get. If you cannot service the unit every 2 years as is recommended by ATSG then the failure is on you. No, fluid failure is only see on units that never get serviced, I rebuild many that get flushed by garages that know nothing about the unit they're flushing and when it won't shift or codes come up it's towed to my shop. ATSG recommends never to flush any unit period. They are my source for training, updates, modifications and general information, so my opinion comes from experience not what some company says to sell there products.
Interesting to see that you recommend servicing the unit to a far greater level than the manufacturer? Why?

But you never answered all of my questions. So I will ask again.

1. If you are just looking to replace the fluid, a total fluid exchange is better than just replacing 1/3 of the fluid, would you agree? (remember Ford used to have a drain plug in the TC) Is the new fluid cleaning the remaining fluid that was not changed?

2. Based on what you say, why does the normal transmission operation not disturb "the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged"?
Why would a fluid exchange service disturb, everything?

3. Do know how the BG trans machines work? Maybe you have no desire to, but you should know how something works before you state the opinions of what some organization says to sell their training updates.

I agree there are inferior products on the market. BG tests most of them, utilizing the ASTM standard for testing fluids, not a BG test, a fluids industry test.

I do not doubt you see transmissions that were recently flushed. I find people think flushing the trans is going to fix it, IT WON'T.

Please contact ATSG about the base stock for synthetic transmission fluid, and report back to us "uninformed experts on this site."

BTW, my knowledge comes from 35 years in the industry as a technician, and 25 years with a major manufacturer, 15 of that in engineering. So my opinions are based on all of that, not just salesman stuff.

I have never claimed to be an expert, and I willing offer my opinions weather people want to hear them or not...:p:
 

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Interesting to see that you recommend servicing the unit to a far greater level than the manufacturer? Why?

But you never answered all of my questions. So I will ask again.

1. If you are just looking to replace the fluid, a total fluid exchange is better than just replacing 1/3 of the fluid, would you agree? (remember Ford used to have a drain plug in the TC) Is the new fluid cleaning the remaining fluid that was not changed?

2. Based on what you say, why does the normal transmission operation not disturb "the metal particles that settle in the pan, torque convertor and case which causes valve body issues because the filter is old, hard and now plugged"?
Why would a fluid exchange service disturb, everything?

3. Do know how the BG trans machines work? Maybe you have no desire to, but you should know how something works before you state the opinions of what some organization says to sell their training updates.":p:


I agree there are inferior products on the market. BG tests most of them, utilizing the ASTM standard for testing fluids, not a BG test, a fluids industry test.

I do not doubt you see transmissions that were recently flushed. I find people think flushing the trans is going to fix it, IT WON'T.

Please contact ATSG about the base stock for synthetic transmission fluid, and report back to us "uninformed experts on this site."

BTW, my knowledge comes from 35 years in the industry as a technician, and 25 years with a major manufacturer, 15 of that in engineering. So my opinions are based on all of that, not just salesman stuff.

I have never claimed to be an expert, and I willing offer my opinions weather people want to hear them or not...:p:
If you have 35 years as a tech you should be able to answer all those questions your self.........if you want to flush your transmission please do but don't spread your word as gospel, it isn't. Also with all those years of experience you should be 75+ in age or were you a tech for 6 months 35 years ago and moved on? Sounds to me your just a BG salesman.:p:
 
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