Transmission fluid change anxiety -- somebody talk me down ...

[6716]

I'll start here: at 195K miles, I don't know that the transmission fluid has ever been changed <insert shocked expressions and / or snarky responses here>.

When I got around to asking about it 50k miles ago, my regular fluids shop wouldn't do a flush. So I just kept driving. Yes, the x-fer case, diffs, and engine oil are all on schedule.

I'm putting together my 200K service list, and I really ought to do something about that transmission fluid and filter. I've looked at just the pan drop and filter exchange, and I've looked at the full drain / refill using the trans pump and emptying out through the cooler line. Y'all have done some fine work on those threads so far, and I thank you.

When I do, whichever I do, the transmission either will or won't work when I go to get back on the road. I've read the reasoning on both sides. I'm not necessarily looking for reassurance that everything will be OK (though if somebody out there has seen the transmission crap out after a similar procedure, it would be interesting to hear the story).

MY QUESTION IS: In the case that this procedure does fry the transmission, is there any way to get a sense of what would need to be done to get back up and running? What part(s) of the transmission would be affected? Am I talking full replacement, or swapping out some parts at a reputable shop? I know generally where the transmission is and overall what it does, but after that I'm a little fuzzy on the inner workings.

I will say that at the moment I don't have any transmission issues. Don't tow much ever. Take it pretty easy on the thing mostly.

Thoughts?

 

[CaptainXL]

Dexron 6 fluid exhange at the dealer. A complete 15 quart fluid exchange. Gets you a total makeover on your tranny. Best $120 I have ever spent at a dealer. No mess, no dropping the pan and no buying the tranny fluid. Nice, clean and done with. I am very happy with this service.

I was going to do this myself by disconnecting the cooler lines but then I went to the checkout at Walmart with 15 quarts of Dexron VI and saw the $90 total. Needless to say I returned the Dexron 6 and headed straight to the dealer. Oh they also had a $10 off coupon for any service over $100. So it ended up being $110. Awesome deal.

 

[AtlWrk]

The pan drop and filter change is perfectly safe to do. It is required maintenance. There's some debate regarding the cooler line method but, borrowing the FDA's lingo, it's GRAS (generally regarded as safe).

What IS considered dangerous is powered flushes that unscrupulous shops sometimes push on unsuspecting consumers. The fact that your shop wouldn't do one speaks well for them. Powered flushes are what have the potential to eventually wreck your tranny.

How is your fluid? Translucent and red or brown and/or burnt smelling?

 

[NewfieEnvoy]

I asked my garage (who I have full faith in) about flushing a transmission and they said they would never do a transmission flush unless its already experiencing some issue. They would do a flush in an attempt to rectify an issue and avoid having to remove and rebuild. More of a desperation last chance effort. I'd drop the pan, filter and fluid, and based on how everything looks maybe do another one at a short interval.

 

[CaptainXL]

Let me dispell a common myth floating around about this because at one point I had superstitous thoughts floating in my brain as well...

I looked into this so called "flushing" techniques used by shops.

Flushing a transmission is nothing more than a complete fluid exchange. It's perfectly safe to do and recommended.

It's done by numerous and well respected tranny shops. GM also has dealerships providing exhanges as well.

 

[6716]

How is your fluid? Translucent and red or brown and/or burnt smelling?

Brownish red, but no burnt smell. Actually, not much smell at all.

Maybe I'm gun shy. When I was having furnace trouble, one of the guys over the phone said "Go stick your nose right at the exhaust pipe, and tell me what you smell." "Holy $%^&! My @#$%ing nose is on fire! What is that?" "Probably about 2000 ppm carbon monoxide ... but I know what your problem is now. I'll send a tech."

 

[hockeyman]

I did mine last week and actually feel a slight bit of difference in how it shifts. As I've mentioned here in post #19, it feels as though it goes into gear a bit faster and smoother.
Maybe it's just a fallacy though...

I'd highly recommend it. Besides, it's cheaper than replacing a trans...

Oh, and I just turned 120k

 

[BRomanJr]

Let me dispell a common myth floating around about this because at one point I had superstitous thoughts floating in my brain as well...

I looked into this so called "flushing" techniques used by shops.

Flushing a transmission is nothing more than a complete fluid exchange. It's perfectly safe to do and recommended.

It's done by numerous and well respected tranny shops. GM also has dealerships providing exhanges as well.

+1

The Tire/Repair shop I use for "stuff I don't want to do" has a BG branded device that utilizes only the transmission pump to exchange clean fluid from one reservoir into the trans and dirty fluid out to another reservoir.
They did use a "cleaner" in the trans for 15 minutes then added a "conditioner" to the new Synthetic fluid reservoir and did the exchange.
$140 and 45 minutes later it was done.
This was done at 165,000 which was shortly after I bought my Truck and not knowing the history.

I have had them perform this process on all of my used GM vehicle purchases in the last 10 or so years (about 8+ vehicles) and no problems.
To those that are curious, I buy, use and sell vehicles for family use and when sold each one was running and driving fine.

 

[The_Roadie]

Anybody have a link that explains the physics behind what THEY think is the technical problem with a flush on an old tranny?

Most of what I've heard has been flapdoodle about dislodging sludge, and junk that should not be built up in any transmission. If it's old enough to have a significant sludge build-up, it's not like the sludge is
"holding the tranny together" or spackling in the gaps and removing it would be a bad thing.

What am I missing about what I think is some sort of redneck urban myth to make people feel better who have been ignoring required maintenance. See my avatar for what I think about that.

 

[CaptainXL]

Anybody have a link that explains the physics behind what THEY think is the technical problem with a flush on an old tranny?

I bet 90% of the time someone gets their transmission fluid changed either partially as in a pan drop or fully in an exchange is because they have symptoms. In those cases it is already too late and the tranny dies shortly thereafter. It doesn't fail from the new fluid but from the old fluid that was never changed. It would have failed either way.

 

[The_Roadie]

I think you're right on - folks all the time confuse coincidence with cause->effect relationships. I prefer to find out the physics behind causality before jumping to conclusions.

 

[CaptainXL]

I think you're right on - folks all the time confuse coincidence with cause->effect relationships. I prefer to find out the physics behind causality before jumping to conclusions.

i will see if i can find anything. My gut instinct is that I read this somewhere, just can't remember where exactly. It was either over at BITOG or a tech article.

 

[NewfieEnvoy]

Don't kill the messenger! Just relaying what I was told. So is it possible my garage doesn't do a flush because there not enough money to be made for the time spent? Or is it possible they don't want to do a flush because as someone said the person looking for a flush may already be having tranny issues and the garage that performs a flush on the mythical creature they call an auto trans will have a finger pointed at them?

 

[6716]

Anybody have a link that explains the physics behind what THEY think is the technical problem with a flush on an old tranny?

Most of what I've heard has been flapdoodle about dislodging sludge, and junk that should not be built up in any transmission. If it's old enough to have a significant sludge build-up, it's not like the sludge is
"holding the tranny together" or spackling in the gaps and removing it would be a bad thing.

What am I missing about what I think is some sort of redneck urban myth to make people feel better who have been ignoring required maintenance. See my avatar for what I think about that.

Hang on there, Roadie ...

These guys are engineers .... they have charts .... http://www.tappi.org/Downloads/unsorted/UNTITLED---NW99273pdf.aspx

The sophisticated approach to the myth is (and I paraphrase only) that detergents in the new stuff dislodges chunks which blocks the valves, which causes the problems. And due transmission sump filters which don't actually filter much because the media is not super fine, the gunk doesn't get caught in the filter but does arf up the valves.

I have been told the "gunk is holdin' 'er all together, so don't touch nuthin' " story, as well.

Not that the link says anything about transmission flushes, just about filtration. Or that I disagree with you.

 

[CaptainXL]

Don't kill the messenger! Just relaying what I was told. So is it possible my garage doesn't do a flush because there not enough money to be made for the time spent? Or is it possible they don't want to do a flush because as someone said the person looking for a flush may already be having tranny issues and the garage that performs a flush on the mythical creature they call an auto trans will have a finger pointed at them?

Probably the later. My tranny shop asked me how many miles I had and how it drives when I asked how much the service was.. So that makes you kind of wonder. Its not a high risk proceedure but Im sure they would like to avoid legal hassles as much as possible. Eventhough the tranny shop would win in court if it ended in a battle. Im sure all smart tranny shops document a list of customer concerns and vehicle symptoms before beginning work just so the customer cant come back at them.

 

[6716]

These guys Tranny Filter Tech seem to say that the research seems to say that there ain't nothing wrong with the ATF per se, there's just too many contaminants in it, and if you put in a more fine filter in the cooler line, you'll screen all that stuff out.

 

[Mooseman]

I did my own flush AND pan drop last year. My fluid was brown and looked burnt. 30K km later, still going strong.

What is important is that with the flush they drop the pan, clean it and the magnet and replace the filter. I am leery of any flushing system that uses its own pump for the flush as that might overpower the tranny's pump (maybe, I dunno, just thinking here). But a flusher that uses the tranny's pump should be fine.

 

[Sparky]

I've heard of so-called "reverse flushes" that can cause trans issues by pushing anything collected by the filter back off of it and shoving it backwards into the trans. That's how one place bragged they didn't need to change the filter because the reverse flush will "clean" the filter too. Well gee, what happens to that stuff then huh?

 

[6716]

Hang on there, Roadie ...

These guys are engineers .... they have charts .... http://www.tappi.org/Downloads/unsorted/UNTITLED---NW99273pdf.aspx

The sophisticated approach to the myth is (and I paraphrase only) that detergents in the new stuff dislodges chunks which blocks the valves, which causes the problems. And due transmission sump filters which don't actually filter much because the media is not super fine, the gunk doesn't get caught in the filter but does arf up the valves.

I have been told the "gunk is holdin' 'er all together, so don't touch nuthin' " story, as well.

Not that the link says anything about transmission flushes, just about filtration. Or that I disagree with you.

Sooooo .....

VALVES, to both quote myself and answer my own question.

Not that that's right, but it's an answer.

If there is any shred of truth to the myth, then the affected parts would be the valves, if the crud got knocked loose either with the flush process or the "new detergents" knocked crud loose, then it's the valves that have been affected. ish. maybe.

But some folks may have been in transmission trouble before their flush as well.

Possibly.

How about "shit happens," and "nothing lasts forever"? Or "won't know 'til you try"?

 

[CaptainXL]

I've heard of so-called "reverse flushes" that can cause trans issues by pushing anything collected by the filter back off of it and shoving it backwards into the trans. That's how one place bragged they didn't need to change the filter because the reverse flush will "clean" the filter too. Well gee, what happens to that stuff then huh?

There was a post on here a few months ago where someone looked into this and found that it was impossible to do a reverse flush on auto transmissions because of some check valve (pump?). I would have to dig for it.

If I remember correctly the dealer did say they introduce a quart of transmission flush prior to chasing it through the cooler lines with the 15 quarts of fluid. Conditioner is added as well.

 

[6716]

These guys Tranny Filter Tech seem to say that the research seems to say that there ain't nothing wrong with the ATF per se, there's just too many contaminants in it, and if you put in a more fine filter in the cooler line, you'll screen all that stuff out.

Anybody have any thoughts on this in-line fine filter idea?

 

[NewfieEnvoy]

Can someone remind me how many liters of fluid would be in the pan to change vs the total in the trans? I know I did read it on here somewhere.

 

[CaptainXL]

Anybody have any thoughts on this in-line fine filter idea?

Another filter wouldn't be bad. You would have to remember to change it though. Someone just put a Derale on not too long ago.

But that won't extend the life of the fluid if that't what your thinking.

Derale Remote Transmission Filter Kit Derale Accessories and Parts D13090

Can someone remind me how many liters of fluid would be in the pan to change vs the total in the trans? I know I did read it on here somewhere.

Automatic Transmission (Pan Removal)

5.0 quarts (4.7 liters)


Automatic Transmission (Complete Overhaul)

11.0 quarts (10.6 liters)

 

[WarGawd]

Dexron 6 fluid exhange at the dealer. A complete 15 quart fluid exchange. Gets you a total makeover on your tranny. Best $120 I have ever spent at a dealer. No mess, no dropping the pan and no buying the tranny fluid. Nice, clean and done with. I am very happy with this service.

I was going to do this myself by disconnecting the cooler lines but then I went to the checkout at Walmart with 15 quarts of Dexron VI and saw the $90 total. Needless to say I returned the Dexron 6 and headed straight to the dealer. Oh they also had a $10 off coupon for any service over $100. So it ended up being $110. Awesome deal.

Except that no dropping the pan means no filter change. At 200k, OP would probably benefit from a filter change.

 

[CaptainXL]

Except that no dropping the pan means no filter change. At 200k, OP would probably benefit from a filter change.

Definitely change the filter at some point. I recommend doing the filter the same time the fluid exchange is done.

You could drop the pan and change the filter yourself but it will require 5 quarts of fluid and Dexron VI goes for about $8 a quart. That's $40. Plus the cost of the filter kit - $25. That's $65.

The dealer can drop the pan and change the filter when they do the fluid exchange for an additional $65. That's what I was quoted at the time.

So it's not worth the time or effort at all. Just get it all done at the GM dealer. Just make sure to ask to see the pan magnet and old filter so you know it was done.

 

[6716]

Definitely change the filter at some point. I recommend doing the filter the same time the fluid exchange is done.

You could drop the pan and change the filter yourself but it will require 5 quarts of fluid and Dexron VI goes for about $8 a quart. That's $40. Plus the cost of the filter kit - $25. That's $65.

The dealer can drop the pan and change the filter when they do the fluid exchange for an additional $65. That's what I was quoted at the time.

So it's not worth the time or effort at all. Just get it all done at the GM dealer. Just make sure to ask to see the pan magnet and old filter so you know it was done.

Quoted $285 this morning by my local Chev dealer for pan drop, filter, exchange.

 

[CaptainXL]

Quoted $285 this morning by my local Chev dealer for pan drop, filter, exchange.

Well I know the flush is $120 advertised on the wall at my dealer service center. I would say if your dealer is charging $160 to drop the pan then I would go someplace else. Local trans shop here wanted $100. They wanted to sell me on the flush stating that the flush is better because it cleans the filter and exchanges all the fluid. But obviously you still got the magnet to clean. Now i asked about the filter and they said to leave it in. Causes more problemz removing it and they never get clogged anyway as they are just a mesh screen. If the filter gets clogged or chunks of metal on the magnet you got bigger problems. At that point there aint no pan drop and filter replacement that will save your hide. Regardless if a new filter and fluid is installed or not.

 

[dfc739]

Well I know the flush is $120 advertised on the wall at my dealer service center. I would say if your dealer is charging $160 to drop the pan then I would go someplace else. Local trans shop here wanted $100. They wanted to sell me on the flush stating that the flush is better because it cleans the filter and exchanges all the fluid. But obviously you still got the magnet to clean. Now i asked about the filter and they said to leave it in. Causes more problemz removing it and they never get clogged anyway as they are just a mesh screen. If the filter gets clogged or chunks of metal on the magnet you got bigger problems. At that point there aint no pan drop and filter replacement that will save your hide. Regardless if a new filter and fluid is installed or not.

The filter is more than just a "mesh screen". The filter has several layers of cellulose filtration media and removes particulates that can either make valves stick or increase wear on anything that moves in the transmission. Like you said, I view pan removal as a way to predict problems down the road. The magnet just has some dark fuzzy stuff: good, that's normal. The magnet has large chunks of metal: better start looking for another transmission.

 

[CaptainXL]

There better be no cellulose in my trans filter. That would cause problems right there if any of it came loose.

You got me curious about trans filter design now. Gonna do some research and get back.

 

[dfc739]

There better be no cellulose in my trans filter. That would cause problems right there if any of it came loose.

You got me curious about trans filter design now. Gonna do some research and get back.

Cellulose? It's the same stuff used in oil filters, fuel filters, air filters, etc. It's just like cotton. How often do chunks of your pants fall off for no reason?

 

[CaptainXL]

Cellulose? It's the same stuff used in oil filters, fuel filters, air filters, etc. It's just like cotton. How often do chunks of your pants fall off for no reason?

Yeah. I was thinking about something else. Would still be cool to see how our filters are made though.

 

[6716]

Thanks everyone for chiming in.

Here's what I think I'm going to do:

Start with a pan drop and filter change, which I'll do myself, for a few reasons.

1. It's something I have never done, so I figure I'll do it once to see what it's all about. I've changed my own engine oil myself exactly once in my life, and that convinced me that for the mess and fooling around, it's a better deal (to me) to get oil changes done by someone else (while they also rotate the tires and look for all the stuff they'd like to upsell me on, which I can do myself).

2. The transmission is sort of a "black box" to me, so I don't mind getting into it a little bit to see what I will learn. I've learned a ton already just getting ready to look at the work.

3. I'm interested to see what the stuff on the magnet looks like, and I'd rather see it myself than have the condition reported to me.

4. In the case I figure out that the transmission is in some trouble, and needs work (not that this work would have wrecked it, just that it may reveal the work that needs to be done), I'll save a few quarts of Dexron VI without going for the full exchange right off the bat. If everything checks out, I can still do the full exchange later. Sure you risk a few quarts of fluid either way, but there you have it.

5. It gives me a chance to check out one of the lifts at the do-it-yourself garage I've been wanting to try. Maybe I can get the diffs at the same time.

6. It keeps me from getting in over my head right off the bat. I have to be careful not to overestimate my skills or enthusiasm BEFORE I'm up to my ears and cranky. It's not unusual for me to have the truck apart overnight when I get into something and start to figure out all the things I didn't know to ask. If I go to this garage 40 minutes from my house, it won't be good to still not be done before they all want to go home for the night. Shoot, it took me three tries to get upper ball joints done, and in the end I stripped it all down and took the knuckles to a shop with the ball joints still in, and had them swap 'em out for $30.