To Change or Not Change my Transmission Fluid & Filter

[jcsinc]

Hello Forum Members,

I am the original owner of a somewhat well maintained 2011 Tahoe. I say somewhat because it have 129K miles and I've kept all the maintenance up on it with exception to the changing the tranny fluid. And the only reason why I haven't done so, it appears GM doesn't make it easy to do it yourself.

Some say when you have that many miles on it, don't touch it. But I wanted to get the forum members opinion. And if I should change it, what am I in for (is it really a lot of work) since I'm a do it yourselfer when it comes to maintaining my vehicles, because it's hard to trust some shops if I can change the fluid and filter with the appropriate tools.

Thanks
jcs

 

[Foggy]

It's not that hard to do... The exhaust work around is the toughest part
When taking off the pan. You'll at least know the condition by whats in the pan.
At your mileage, the torque converter is prob getting ready to go bye bye...
So weigh that in your decision. You might be better off changing the Torque Conv
before the clutch inside it explodes. You can only do this BEFORE you are having
issues.
IMO It doesn't matter to me mileage. Our Trannys have a nice serviceable dipstick
and fill tube and Filter unlike most late models. So I do the service

 

[swathdiver]

Change the fluid and run it on the severe service schedule.

You don't have to change the filter this time around. I didn't drop my pan until about 190K but did exchange all the fluid several times before then.

 

[B-train]

Get a small hand, or 12v, pump. Drop the pan down and let it drain out the front. Use the pump to suck out the rest. Wipe the gasket area......gingerly so as to not get any dirt inside the pan. Mount it back up and refill with approximately 6 quarts.

Personally I'd change the filter at 129k, but I understand the pan/exhaust headache is REAL! You can use a long, sturdy, prybar and flex the crossover section down just enough to slide it out, done it many times......hated every one of them too. If you do go this route, be careful of the solenoids and wiring so you don't break anything off in the process.

Another option is to search this awesome forum for threads about DIY trans flush with the cooler lines at the radiator. That may work just fine for you as well and then in theory you'll be getting more clean fluid in than just what's in the pan. You can buy a 5 gallon bucket of Dexron 6 at tractor supply and flush to your heart's content.

 

[tom3]

I'd want to take the pan off, see what's in the bottom, clean the magnet, new filter. And I'd do it on a high mileage machine for sure.

 

[Marky Dissod]

Some say when you have that many miles on it, don't touch it.

Outdated bullschidt that USED to apply to Dex3 & the 4L60E's GM OE clutch materials back then
(also see 'it needs a little backpressure).

6L80E's chief failure mode is when the torque converter clutch comes apart and takes the 6L80E out with it.
A used-ATF analysis will tell you definitively if you need to replace that TCC or not, otherwise replace it to be safe.

The TCC will last MUCH longer if you disable V4 mode & tune the tcm for negligible slip.
(GM OE TCC slip margins are why the TCC is the 6L80E's cheif failure mode, 6L90Es last longer.)

 

[rdezs]

That is way too long. I would drop the pan, change the filter, as well as do the flush through the lines to the radiator.

You might consider getting a vacuum extractor. It's a simple as sticking the tube down the dipstick tube and sucking the pan dry. I not only change my ATF every 30,000 miles on our 2014 Escalade, about third oil change I use the vacuum extractor to suck out what's in the pan, measure it precisely, and replace it.

I also run an inline spin on hydraulic filter.

Coming up on 200,000 miles this summer, never an issue with the transmission. I did go in at about 100,000 miles and tightened up the shifting using the Diablo predator 2.

 

[rdezs]

 

[donjetman]

I've dropped my exhaust twice and changed the atf & filter, 2018 at 131k miles & 2022 at 174k miles.

Installed a new torque converter in 2018 at 131k miles too.

Still going strong today at 200k.

I do a dump and fill every 25k miles, and change the filter too every 50k.

I've done 3 used atf analysis reports in the last 6+ yrs and 70k miles to guide me.

 

[rdezs]

There is a shortcut so you don't have to pull the exhaust pipe. With a long pry bar, you can flex the pipe down about an inch, just enough that the transmission pan will come out. Easier with the second person holding the pry bar, but not absolutely necessary. It's what all the shops do on these.

 

[rdezs]

Hello Forum Members,

I am the original owner of a somewhat well maintained 2011 Tahoe. I say somewhat because it have 129K miles and I've kept all the maintenance up on it with exception to the changing the tranny fluid. And the only reason why I haven't done so, it appears GM doesn't make it easy to do it yourself.

Some say when you have that many miles on it, don't touch it. But I wanted to get the forum members opinion. And if I should change it, what am I in for (is it really a lot of work) since I'm a do it yourselfer when it comes to maintaining my vehicles, because it's hard to trust some shops if I can change the fluid and filter with the appropriate tools.

Thanks
jcs

I've heard that screwed up logic before, and that's exactly what it is. Think about it. It's like saying you went 20,000 miles without changing your engine oil. So then maybe it's best to just keep running it and don't change it? The new oil might actually cause harm? LOL. Every mechanical component out there benefits from fresh oil or grease.

 

[bill1013]

I've heard that screwed up logic before, and that's exactly what it is. Think about it. It's like saying you went 20,000 miles without changing your engine oil. So then maybe it's best to just keep running it and don't change it? The new oil might actually cause harm? LOL. Every mechanical component out there benefits from fresh oil or grease.

New fluid has additives to keep seals, O rings and other rubber parts soft and supple. Usually it’s something along the line of Anolins. The problem happens when the old seal or O ring has a crack or worn spot where the Anolin contacts the inner rubber and begins to swell and eventually turns to black “bubble gum” and fails.

This usually happens when you put new fluid in an old floor jack. The jack works, at first, but shortly there after it fails. Hopefully no one is under the load when it fails. Sometimes it’s better to put corn oil in the jack as it has no softening agents in it.

 

[PPV_2018]

I've heard that screwed up logic before, and that's exactly what it is. Think about it. It's like saying you went 20,000 miles without changing your engine oil. So then maybe it's best to just keep running it and don't change it? The new oil might actually cause harm? LOL. Every mechanical component out there benefits from fresh oil or grease.

guess i will play devil’s advocate here.. it might be screwed up logic, but there is a reason why the old wives tale came to be in the first place.. and it has some truth to it

I’ve seen it happen on a 70k mile 4l60e(?) many years ago, when it never had trans service done, and then they got talked into doing a trans flush, and within a 100 or so miles, trans started slipping and failed soonafter . I’ve also seen this same phenomena on a few other vehicles.

Flame me if you want, but I’ve seen this story personally quite a few times.

Then some people say if you change the fluid and the trans goes out, it was going to go out soon anyways. maybe so.. but *if* i was in that position, i think I’d take my chances with the older fluid. Putting new fluid isn’t going to save your trans if it’s dying anyways, which is what most people who have an abused transmission think will happen.

Bottom line change the trans fluid per mfg instructions and you won’t be in this position

 

[rdezs]

Lol, I'm pretty sure that yeah, the transmission was headed out already. Probably why the fluid was changed due to symptoms

 

[jcsinc]

Thanks forum Members for the replies and I'm going to go ahead and perform the fluid & filter, pan gasket change as recommended. And it appears I need to get about 6qts of Dextron VI synthetic fluid, (I assume it's best not to use another brand, since the TC still hold a lot of the old fluid).

Thanks
jcs

 

[Scrappycrow]

Dextron

This is a really common error, but it's Dexron -- no "t" in the name.

 

[rdezs]

Yes, you're absolutely correct. Lol, have no idea where the use of the 'T' ever started.

 

[donjetman]

There is a shortcut so you don't have to pull the exhaust pipe. With a long pry bar, you can flex the pipe down about an inch, just enough that the transmission pan will come out. Easier with the second person holding the pry bar, but not absolutely necessary. It's what all the shops do on these.

I might give that a try next time

 

[Charlie207]

I might give that a try next time

Just undo the band clamp where the y-pipe connects to the intermediate pipe. It'll allow the front of the exhaust to flex more.

 

[Foggy]

guess i will play devil’s advocate here.. it might be screwed up logic, but there is a reason why the old wives tale came to be in the first place.. and it has some truth to it

I’ve seen it happen on a 70k mile 4l60e(?) many years ago, when it never had trans service done, and then they got talked into doing a trans flush, and within a 100 or so miles, trans started slipping and failed soonafter . I’ve also seen this same phenomena on a few other vehicles.

Flame me if you want, but I’ve seen this story personally quite a few times.

Then some people say if you change the fluid and the trans goes out, it was going to go out soon anyways. maybe so.. but *if* i was in that position, i think I’d take my chances with the older fluid. Putting new fluid isn’t going to save your trans if it’s dying anyways, which is what most people who have an abused transmission think will happen.

Bottom line change the trans fluid per mfg instructions and you won’t be in this position

To add to your experience: 4L60's in stock form suck... Also, NEVER NEVER EVER
do a "transmission flush" WithOut dropping the pan, replacing the filter, cleaning the
pan and refilling with fresh fluid... "flushing" just circulates all **** that's in the pan and
what the filter has done it's job to trap.