Changing transmission fluid

[docnascar]

My 2010 silverado is creeping up on 30k miles. I pretty much only use it for towing or hauling something. Tranny temps while towing are typically around 200-220 and some minor runs at 235 on large grades.

I've always been the person that never changes tranny fluid on my vehicles. Probably won't on any of my cars going forward. However, this truck is the "work horse" and I'm pondering if I should, since its being used harder. I say harder because the max tow rating of this truck is 4700lbs and my camper is ~3500lbs.


Thoughts?

[Cummins12V98]

Lurker52 wrote:
I have 2 friends who own tranny shops. They both said not to change the fluid unless it was getting brown and smelling burnt. They said changing it can cause proplems from loose debris getting in the tranny. I tow heavy and full time. Tranny heat is my biggest concern in my 05 Dodge automatic. I follow towing reccomendations and check all my fluids regulary. I also don't push the truck up hills. I let it find a gear and roll up the hill. I trust my friends who have about 60 years combined tranny experience.

I assume bad transmissions keep them in business?????

[wintersun]

With the transmissions supplied with the light duty gas powered trucks the filter is changed at 100k miles and the fluid interval depends upon the type of duty. Severe duty, as with heavy towing, shortens the service interval. Use Dexron VI which is designed for use with the type of seal material used in GM transmissions. Foolish to use anything else in the way of ATF.

I use my truck 50% of the time in a severe duty mode so I split the difference between the normal duty and severe duty service intervals.

[Lurker52]

I have 2 friends who own tranny shops. They both said not to change the fluid unless it was getting brown and smelling burnt. They said changing it can cause proplems from loose debris getting in the tranny. I tow heavy and full time. Tranny heat is my biggest concern in my 05 Dodge automatic. I follow towing reccomendations and check all my fluids regulary. I also don't push the truck up hills. I let it find a gear and roll up the hill. I trust my friends who have about 60 years combined tranny experience.

[CKNSLS]

LarryJM wrote:

BurbMan wrote:
Larry, you have a real pair of brass ones to sit there and say that your opinions are fact are mine are misguided. I am looking at the Helm factory service manual provided to dealers for the correct service and repair of GM vehicles. I am looking at page 7-325 that talks about fluid replacement for the 4L60E. in summary it says to drop the pan, replace the filter, install the pan, and fill with fluid to the correct level. Disconnecting lines is only referenced with regard to checking line pressure, checking cooler flow, etc. the same procedure is givenj on page 7-575 for the 4L80E.

granted my manual is for 2001 vehicles and may not be applicable to the OPs 2010 Silverado, but certainly no less appliacble than your service knowledge of your Ford vehicle.

as a reminder, this is a public forum and for you to indict my opinions has dangerously misleading while canonizing yours as unimpeachably correct is the height of arrogance and ridiculousness. You must not have many friends.

Well this is the first time you have even hinted at what you used to reference your posts and I will only remind folks that in your first post your were flat out wrong on the % of fluid changed with a pan drop and fill so that tells me you are loose with your facts to start with. I also provided "FACTUAL" info with even page and reference on the statement made here that GM manual specifically says not to FLUSH the Transmission and that came directly from a 2010 Silverado manual. Not to your reference to your 2001 manual, you should IMO have stated where it came from since who knows if that procedure is applicable to this particular year and model since again you don't have the current facts for the specific model you are talking about. As far as me mentioning the procedure for my 2001 Ford, I specifically mentioned in my very first post IIRC that I didn't know the specifics for the GM trucks, but one should be similar so I didn't in ANY WAY base my information solely on that vehicle only. In using your 2001 service manual and ASSUMING it is exactly the same as what is applicable to the 2010 Silverado in this thread is IMO even a more flagrant playing with the facts as it might apply here. A simple google for Silverado tranny fluid changes will show to anyone interested that what I have been describing and even doing the type of flush that I don't think is prudent is common and even used by dealerships and I would submit that MOST dealerships and tranny/service shops do much more than a simple drop the pan and fill, with most using a tranny flush machine and I won't go there since that is a whole other topic for discussion.

I would highly encourage folks to go back and look at my first post in this thread and the misfacts stated by you and what my reply was and exactly what I said which your most recent response has seemed to TOTALLY IGNORE. I have and will continue to contend that your asseration that

it's more valuable to drop the pan and change the filter than it is to flush 100% of the fluid. You will have 3/4 of the fluid replaced by dropping the pan, and the remaining 25% of teh old fluid won't hurt anything

is flat out wrong, not factual, and not supported by any reputable source. NOTE: you used flush which I have issues with and take that as meaning changing 100% or as close to as possible which I do agree with.

Your taking this to the personal level with digs as to who and how many friends I have and to lighten up, and using terms like arrogance and ridiculousness w/o specific reference just tells me that is generally what happens when one in faced with the embarassement of admitting they are not correct and the only way to save face is to take it to a personal level. That is IMO TRULY SAD. I'm GLAD as CKNSLS sees my point even if you and some other seem to want to ignore the facts and common sense. I will not you still haven't substantiated that outrageous statement about it not being advisable at times not to change as much tranny fluid as possible.

I just love it when folks try and dig themselves out of a hole and fail to realize that they are only making the hole deeper and deeper:p

O.K. all good things have to end and I'm not childish as some on insisting to always having the last word in a conversation so I'm THRU here since I think I have made my points to those that want good information and if one wants my specific input any further on this particular topic, please PM me since as I said I'm THRU with this particular thread.

Larry

Larry, The thing is you have "old school" attitude and there are those who have heard something twenty years ago and then in their mind it's set in stone. A modern tranny flush is nothing more than taking the old fluid out and putting new fluid in. AGAIN, for anybody that buys a new Silverado the power train is GM's responsibility for the first 100K. They are not going to authorize a procedure that will cause harm when GM WILL HAVE TO FIX IT. But, this is common sense and we all know......oh...oh..better not go there!

[LarryJM]

BurbMan wrote:
Larry, you have a real pair of brass ones to sit there and say that your opinions are fact are mine are misguided. I am looking at the Helm factory service manual provided to dealers for the correct service and repair of GM vehicles. I am looking at page 7-325 that talks about fluid replacement for the 4L60E. in summary it says to drop the pan, replace the filter, install the pan, and fill with fluid to the correct level. Disconnecting lines is only referenced with regard to checking line pressure, checking cooler flow, etc. the same procedure is givenj on page 7-575 for the 4L80E.

granted my manual is for 2001 vehicles and may not be applicable to the OPs 2010 Silverado, but certainly no less appliacble than your service knowledge of your Ford vehicle.

as a reminder, this is a public forum and for you to indict my opinions has dangerously misleading while canonizing yours as unimpeachably correct is the height of arrogance and ridiculousness. You must not have many friends.

Well this is the first time you have even hinted at what you used to reference your posts and I will only remind folks that in your first post your were flat out wrong on the % of fluid changed with a pan drop and fill so that tells me you are loose with your facts to start with. I also provided "FACTUAL" info with even page and reference on the statement made here that GM manual specifically says not to FLUSH the Transmission and that came directly from a 2010 Silverado manual. Not to your reference to your 2001 manual, you should IMO have stated where it came from since who knows if that procedure is applicable to this particular year and model since again you don't have the current facts for the specific model you are talking about. As far as me mentioning the procedure for my 2001 Ford, I specifically mentioned in my very first post IIRC that I didn't know the specifics for the GM trucks, but one should be similar so I didn't in ANY WAY base my information solely on that vehicle only. In using your 2001 service manual and ASSUMING it is exactly the same as what is applicable to the 2010 Silverado in this thread is IMO even a more flagrant playing with the facts as it might apply here. A simple google for Silverado tranny fluid changes will show to anyone interested that what I have been describing and even doing the type of flush that I don't think is prudent is common and even used by dealerships and I would submit that MOST dealerships and tranny/service shops do much more than a simple drop the pan and fill, with most using a tranny flush machine and I won't go there since that is a whole other topic for discussion.

I would highly encourage folks to go back and look at my first post in this thread and the misfacts stated by you and what my reply was and exactly what I said which your most recent response has seemed to TOTALLY IGNORE. I have and will continue to contend that your asseration that

it's more valuable to drop the pan and change the filter than it is to flush 100% of the fluid. You will have 3/4 of the fluid replaced by dropping the pan, and the remaining 25% of teh old fluid won't hurt anything

is flat out wrong, not factual, and not supported by any reputable source. NOTE: you used flush which I have issues with and take that as meaning changing 100% or as close to as possible which I do agree with.

Your taking this to the personal level with digs as to who and how many friends I have and to lighten up, and using terms like arrogance and ridiculousness w/o specific reference just tells me that is generally what happens when one in faced with the embarassement of admitting they are not correct and the only way to save face is to take it to a personal level. That is IMO TRULY SAD. I'm GLAD as CKNSLS sees my point even if you and some other seem to want to ignore the facts and common sense. I will not you still haven't substantiated that outrageous statement about it not being advisable at times not to change as much tranny fluid as possible.

I just love it when folks try and dig themselves out of a hole and fail to realize that they are only making the hole deeper and deeper:p

O.K. all good things have to end and I'm not childish as some on insisting to always having the last word in a conversation so I'm THRU here since I think I have made my points to those that want good information and if one wants my specific input any further on this particular topic, please PM me since as I said I'm THRU with this particular thread.

Larry

[BeerCan]

BeerCan wrote:

Grit dog wrote:

brooks379 wrote:
They say to never change the trans fluid ????? when did trans fluid last for ever ??? Maybe the manufacture would rather sell owners new transmissions in a few years instead of a couple gallons of trans fluid ???? I don't care what the manufacture says my trans fluid is getting changed regularly !!

Yeah, it's dumb. My last 2 work trucks, '11 F150 and '13 F250 didn't have a dipstick. Neither does the 06 Charger we got last year.
It's getting changed soon even though the reccomended interval on it is 100k.

Is your 2013 F250 a gas or diesel? My diesel 2013 has a transmission fluid dipstick. (refer to page ~313 in the owners manual)

Grit Dog can you answer this? I am curious because not only does my '13 Super Duty (diesel) have a dipstick my '11 F150 (Ecoboost) had one also. Why did your vehicles not have one?

[Charlie_D_]

:B

[BurbMan]

Larry, you have a real pair of brass ones to sit there and say that your opinions are fact are mine are misguided. I am looking at the Helm factory service manual provided to dealers for the correct service and repair of GM vehicles. I am looking at page 7-325 that talks about fluid replacement for the 4L60E. in summary it says to drop the pan, replace the filter, install the pan, and fill with fluid to the correct level. Disconnecting lines is only referenced with regard to checking line pressure, checking cooler flow, etc. the same procedure is givenj on page 7-575 for the 4L80E.

granted my manual is for 2001 vehicles and may not be applicable to the OPs 2010 Silverado, but certainly no less appliacble than your service knowledge of your Ford vehicle.

as a reminder, this is a public forum and for you to indict my opinions has dangerously misleading while canonizing yours as unimpeachably correct is the height of arrogance and ridiculousness. You must not have many friends.

[CKNSLS]

352 wrote:

LarryJM wrote:

Charlie D. wrote:


The OP asked about a Chevrolet transmission not a Ford. If he reads and follows the manual it says Chevy does not recommend a flush. He will be better off following his manual than getting conflicting opinions from owners of the BIG 3. Now I have expressed my opinion.:)

I just love folks that say this or that says this or that and fail to provide any verifiable source to backup their for what I can only call unsubstantiated statements and in your specific case I think your contention that the owner's manual specifically states not to flush the transmission is incorrect and that specific recommendation is no where in the owner's manual for the specific vehicle we are talking about which is a 2010 Silverado.

I actually downloaded the 2010 Silverado Owner's Manual which was 626 pages and no where in those 626 pages does it mention anything about flushes and the transmission. You failed to provide any reference except some reference to the owner's manual so please give us the page nr. and topic title where you find your contention that the transmission should not be flushed or I would advice folks to disregard your post as your personal opinion and nothing more. BTW I have already agreed that certain types of flushes are not IMO a good way to service your transmission. The document I used came from
2010 Silverado Owners Manual and the manual has the part number of 25854757 A First Printing.

I converted this document to a PDF and then did a FULL search on the word flush and what it does say not to "FLUSH" is the engine oil, but does say to "FLUSH" the cooling system.

What is does say on page 6-23 is

Automatic Transmission Fluid
(4-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid

A good time to check the automatic transmission fluid
level is when the engine oil is changed..
Change the fluid and filter at the intervals listed in
Scheduled Maintenance on page 7?3 and be sure to
use the transmission fluid listed in Recommended
Fluids and Lubricants on page 7?13.

A similar procedure is found for the 6 speed auto on page 6-26

Automatic Transmission Fluid
(6-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7?13.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance
on page 7?3. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants on
page 7?13.

Please note in both these they say "FLUID CHANGE" and what I have described doing with with the tranny itself or with the proper machine is exactly that a "FLUID CHANGE". It's not as is normally referred to as a "flush" nor is it a "drop the pan" and fill so what I have described is if you want to follow the owner's manual the closest you can get to a "fluid change". As I have already provided documentation that simply dropping the pan and refilling only changes 5 of the about 12qts in one Chevy tranny and I don't call that by any stretch of the imagination a "FLUID CHANGE". If you do O.K. have at it, but realize what you are actually getting and accomplishing which like one member that thought that got 75% of the fluid changed was way off in his numbers and is basically like the example I gave is doing an engine oil change and putting most of the old oil back in and only adding very little (i.e. less than 50%) new oil.

I leave it to the Chevy owners to figure out the best way to do an effective "FLUID CHANGE".

45Ricochet and 352 your posts are IMO not helpful and do nothing to help or add to the topic being discussed here and I am at a loss to understand why folks like you post the useless type info that you do. I think you should be here to help folks and leave whatever personal agendas and what I can only call "childish" comments such as "Personally I only flush when going #2" you might have at home where they belong.

Finally the apple and oranges statement is questionable here since regardless of make transmissions in their cooling systems are very similar and all have a line out which goes thru the coolers and then a return line in and what I have described for my 4R100 is disconnecting the return line and letting the pump in the transmission push all the fluid thru the internal passages in the tranny and the TC and collect that fluid from the return line, replacing the lost fluid via filling the pan before it runs the tranny dry. This procedure or something very similar should be applicable to many other makes and models of transmissions, but one needs to consult the people actually knowledgeable to get the specifics which at this point no one that has posted in this thread including me has shown that specific level of expertise.


About the only thing I can add in closing is Q.E.D.

Larry

The reason I said go talk to a transmission re builder at a dealership is because what ever I say there will be many who will not believe me. So go hear it from one who knows. I know exactly what happens when you ( FLUSH ) a transmission and I will never do it. When you spend $2500 plus several thousand miles after you ( FLUSH )
You will be thinking about how helpful this post was . So do what you have to do and pay the piper later. I'm finished on this subject and good luck to those who ( FLUSH ).

Larry your explanation of what a proper flush is spot on. Unfortunately, there is a lot of "old school" on this forum.

Let's face it-all these trucks come with a 100K power train warranty. If it was harmful GM wouldn't let the dealer perform it since the transmission would have to be repaired on GM's dime.

That's common sense that sometimes is lacking....

[LarryJM]

BurbMan wrote:
one more comment and i am done here. if you want to talk about opinions and misconceptions, comparing transmission fluid to motor oil is one such. a 100% fluid change is not always advisable nor beneficial as it is with engine oil. Do some research on that...provide YOUR cited references that state that it is advisable to change 100% of the trans fluid. dont assume that it is obvious.

also regarding the flush...my buddy that owned a six bay shop had a trnsmission service machine that was basically two tubes that got inserted down the dipstick tube. Fresh fluid got pumped in one tube, old fluid extracted via the other tube. still not sure how it didnt just suck up the new fluid coming out of the hose right next to the pickup tube.

lastly, ligten up larry, life is too short. go camping! for me, looks like i have to go back to using my block list.....

Well you can say lighten up, but when misconceptions and outright misinformation keeps cropping up just like the one on not changing as much fluid as possible which is IMO BUNK and misleading. If you have a specific reference for what you are contending why didn't you provide it along with that outlandish IMO statement. I fail to understand why you have posted again and as far as I can tell have added ZERO to the discussion and have only muddied the waters with your IMO what can only be called crazy assertion that not changing as much fluid as possible is sometimes advisable.:S

These forums are for sharing knowledge which IMO should be factual and that is all I have done and will continue to do. If one chooses to ignore it fine, and if one questions my facts and I feel that has to have a counter response then I feel it's incumbent on me to do so since doing otherwise just leaves what I consider non facts or imprudent practice out there as being O.K.

On providing a reference on changing as much fluid as possible the real answer is for you, NOT ME to provide your reference why it's not advisable. There might be some EXTREMELY RARE CASE where that would happen, but I don't know of any and since you seem to why not share it instead of keeping it a SECRET:R I hate to provide references for the obvious, but HERE is just one that by doing multiple basic pan drain via the dipstick tube and running the tranny each time does basically the same thing as I have previously described and will get over 80% of the old fluid out.

Here is an example of the above procedure with say a 5 qt pan and 12qt capacity tranny and doing it three times.

1st drain and fill - 5qts new fluid + 7 qts old => 12qts total of 58% old to new fluid

2nd drain and fill - remove 5 qts of 58% mixture and replace with new => this leaves 7qts of the 58% mixture which is made up of 4qts of the original fluid so now you have 8qts of new fluid and 4 qts of the original for a 12 qt total fluid which is a 33% mix of old to new.

3rd drain and fill - removes 5 qts of 33% misture and replace with new => this leaves 7qts of the 33% mixture which is made up of 2.3qts of the original fluid and 4.7 qts of the new fluid. Now you have 12qt that is a mixture of 19% old to 81% new.

Now that's starting to get better, but if you accomplish what I have been talking about you will get 95% new fluid and it only takes about 2 qts more fluid that the total capacity of the tranny. However if you were to do just one more drain and refill for a total of 4 that 81% jumps to 92%, very close to the number I have quoted.

BTW I think my Engine Oil comparision is an EXCELLENT example to use, but you have a right to your opinion, but you don't provide why you think it's a misconception or is misleading. Both fluids are for basically the same thing in different systems.

Larry

[LarryJM]

352 wrote:

LarryJM wrote:

Charlie D. wrote:


The OP asked about a Chevrolet transmission not a Ford. If he reads and follows the manual it says Chevy does not recommend a flush. He will be better off following his manual than getting conflicting opinions from owners of the BIG 3. Now I have expressed my opinion.:)

I just love folks that say this or that says this or that and fail to provide any verifiable source to backup their for what I can only call unsubstantiated statements and in your specific case I think your contention that the owner's manual specifically states not to flush the transmission is incorrect and that specific recommendation is no where in the owner's manual for the specific vehicle we are talking about which is a 2010 Silverado.

I actually downloaded the 2010 Silverado Owner's Manual which was 626 pages and no where in those 626 pages does it mention anything about flushes and the transmission. You failed to provide any reference except some reference to the owner's manual so please give us the page nr. and topic title where you find your contention that the transmission should not be flushed or I would advice folks to disregard your post as your personal opinion and nothing more. BTW I have already agreed that certain types of flushes are not IMO a good way to service your transmission. The document I used came from
2010 Silverado Owners Manual and the manual has the part number of 25854757 A First Printing.

I converted this document to a PDF and then did a FULL search on the word flush and what it does say not to "FLUSH" is the engine oil, but does say to "FLUSH" the cooling system.

What is does say on page 6-23 is

Automatic Transmission Fluid
(4-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid

A good time to check the automatic transmission fluid
level is when the engine oil is changed..
Change the fluid and filter at the intervals listed in
Scheduled Maintenance on page 7?3 and be sure to
use the transmission fluid listed in Recommended
Fluids and Lubricants on page 7?13.

A similar procedure is found for the 6 speed auto on page 6-26

Automatic Transmission Fluid
(6-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7?13.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance
on page 7?3. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants on
page 7?13.

Please note in both these they say "FLUID CHANGE" and what I have described doing with with the tranny itself or with the proper machine is exactly that a "FLUID CHANGE". It's not as is normally referred to as a "flush" nor is it a "drop the pan" and fill so what I have described is if you want to follow the owner's manual the closest you can get to a "fluid change". As I have already provided documentation that simply dropping the pan and refilling only changes 5 of the about 12qts in one Chevy tranny and I don't call that by any stretch of the imagination a "FLUID CHANGE". If you do O.K. have at it, but realize what you are actually getting and accomplishing which like one member that thought that got 75% of the fluid changed was way off in his numbers and is basically like the example I gave is doing an engine oil change and putting most of the old oil back in and only adding very little (i.e. less than 50%) new oil.

I leave it to the Chevy owners to figure out the best way to do an effective "FLUID CHANGE".

45Ricochet and 352 your posts are IMO not helpful and do nothing to help or add to the topic being discussed here and I am at a loss to understand why folks like you post the useless type info that you do. I think you should be here to help folks and leave whatever personal agendas and what I can only call "childish" comments such as "Personally I only flush when going #2" you might have at home where they belong.

Finally the apple and oranges statement is questionable here since regardless of make transmissions in their cooling systems are very similar and all have a line out which goes thru the coolers and then a return line in and what I have described for my 4R100 is disconnecting the return line and letting the pump in the transmission push all the fluid thru the internal passages in the tranny and the TC and collect that fluid from the return line, replacing the lost fluid via filling the pan before it runs the tranny dry. This procedure or something very similar should be applicable to many other makes and models of transmissions, but one needs to consult the people actually knowledgeable to get the specifics which at this point no one that has posted in this thread including me has shown that specific level of expertise.


About the only thing I can add in closing is Q.E.D.

Larry

The reason I said go talk to a transmission re builder at a dealership is because what ever I say there will be many who will not believe me. So go hear it from one who knows. I know exactly what happens when you ( FLUSH ) a transmission and I will never do it. When you spend $2500 plus several thousand miles after you ( FLUSH )
You will be thinking about how helpful this post was . So do what you have to do and pay the piper later. I'm finished on this subject and good luck to those who ( FLUSH ).

Well it's becoming obvious to me you don't understand what a flush is or what a fluid exchange that I am talking about is and I have tried to explain the differences, but for some reason you still don't understand which I can only attribute to a lack of knowledge or experience or a combination of the two. I just hope others have since you're arguing with the wrong person about flushes as I think you are referring to. BTW there are many threads on other sites where even people that are mechanics at Chevy dealerships and those who either own or work in independent shops that even advocate actual flushes that use a machine to push the fluid and chemicals even in reverse which is something I have already said is IMO a BIG NO NO. Doing what I am advocating uses only tranny fluid, NO CHEMICALS and does not "FORCE" the fluid thru the transmission, but simply uses the existing pump in the transmission to natural remove almost all the old fluid and replace it with new fluid. It puts no extra fluid pressure or flow nor introduce any foreign chemicals in the system and is as benign as simply driving your vehicle normally. You seem to want to call that a FLUSH and if so then you truly do not understand what is being discussed here.

Larry

[Charlie_D_]

Our lives would be simpler if the Big 3 would put an oil life monitor on transmissions.

[BurbMan]

one more comment and i am done here. if you want to talk about opinions and misconceptions, comparing transmission fluid to motor oil is one such. a 100% fluid change is not always advisable nor beneficial as it is with engine oil. Do some research on that...provide YOUR cited references that state that it is advisable to change 100% of the trans fluid. dont assume that it is obvious.

also regarding the flush...my buddy that owned a six bay shop had a trnsmission service machine that was basically two tubes that got inserted down the dipstick tube. Fresh fluid got pumped in one tube, old fluid extracted via the other tube. still not sure how it didnt just suck up the new fluid coming out of the hose right next to the pickup tube.

lastly, ligten up larry, life is too short. go camping! for me, looks like i have to go back to using my block list.....

[352]

LarryJM wrote:

Charlie D. wrote:


The OP asked about a Chevrolet transmission not a Ford. If he reads and follows the manual it says Chevy does not recommend a flush. He will be better off following his manual than getting conflicting opinions from owners of the BIG 3. Now I have expressed my opinion.:)

I just love folks that say this or that says this or that and fail to provide any verifiable source to backup their for what I can only call unsubstantiated statements and in your specific case I think your contention that the owner's manual specifically states not to flush the transmission is incorrect and that specific recommendation is no where in the owner's manual for the specific vehicle we are talking about which is a 2010 Silverado.

I actually downloaded the 2010 Silverado Owner's Manual which was 626 pages and no where in those 626 pages does it mention anything about flushes and the transmission. You failed to provide any reference except some reference to the owner's manual so please give us the page nr. and topic title where you find your contention that the transmission should not be flushed or I would advice folks to disregard your post as your personal opinion and nothing more. BTW I have already agreed that certain types of flushes are not IMO a good way to service your transmission. The document I used came from
2010 Silverado Owners Manual and the manual has the part number of 25854757 A First Printing.

I converted this document to a PDF and then did a FULL search on the word flush and what it does say not to "FLUSH" is the engine oil, but does say to "FLUSH" the cooling system.

What is does say on page 6-23 is

Automatic Transmission Fluid
(4-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid

A good time to check the automatic transmission fluid
level is when the engine oil is changed..
Change the fluid and filter at the intervals listed in
Scheduled Maintenance on page 7?3 and be sure to
use the transmission fluid listed in Recommended
Fluids and Lubricants on page 7?13.

A similar procedure is found for the 6 speed auto on page 6-26

Automatic Transmission Fluid
(6-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7?13.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance
on page 7?3. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants on
page 7?13.

Please note in both these they say "FLUID CHANGE" and what I have described doing with with the tranny itself or with the proper machine is exactly that a "FLUID CHANGE". It's not as is normally referred to as a "flush" nor is it a "drop the pan" and fill so what I have described is if you want to follow the owner's manual the closest you can get to a "fluid change". As I have already provided documentation that simply dropping the pan and refilling only changes 5 of the about 12qts in one Chevy tranny and I don't call that by any stretch of the imagination a "FLUID CHANGE". If you do O.K. have at it, but realize what you are actually getting and accomplishing which like one member that thought that got 75% of the fluid changed was way off in his numbers and is basically like the example I gave is doing an engine oil change and putting most of the old oil back in and only adding very little (i.e. less than 50%) new oil.

I leave it to the Chevy owners to figure out the best way to do an effective "FLUID CHANGE".

45Ricochet and 352 your posts are IMO not helpful and do nothing to help or add to the topic being discussed here and I am at a loss to understand why folks like you post the useless type info that you do. I think you should be here to help folks and leave whatever personal agendas and what I can only call "childish" comments such as "Personally I only flush when going #2" you might have at home where they belong.

Finally the apple and oranges statement is questionable here since regardless of make transmissions in their cooling systems are very similar and all have a line out which goes thru the coolers and then a return line in and what I have described for my 4R100 is disconnecting the return line and letting the pump in the transmission push all the fluid thru the internal passages in the tranny and the TC and collect that fluid from the return line, replacing the lost fluid via filling the pan before it runs the tranny dry. This procedure or something very similar should be applicable to many other makes and models of transmissions, but one needs to consult the people actually knowledgeable to get the specifics which at this point no one that has posted in this thread including me has shown that specific level of expertise.


About the only thing I can add in closing is Q.E.D.

Larry

The reason I said go talk to a transmission re builder at a dealership is because what ever I say there will be many who will not believe me. So go hear it from one who knows. I know exactly what happens when you ( FLUSH ) a transmission and I will never do it. When you spend $2500 plus several thousand miles after you ( FLUSH )
You will be thinking about how helpful this post was . So do what you have to do and pay the piper later. I'm finished on this subject and good luck to those who ( FLUSH ).