Transmission Fluid Change potentially causing problems

[Jullian is not my name]

I had my transmission fluid flushed and changed by a non-dealer mechanic about 2 weeks ago at 55k miles and 4.5 years on my 2014 Sierra.  This was the 1st transmission maintenance ever done.  After the the service, I now feel hard shifts at times if I'm in stop and go traffic while rolling and just giving the pedal a little touch after being fully off the accelerator.  I'm getting these hard shifts in other situations too.  I've also experienced a situation when still cold where from a dead stop I'll start accelerating and have the transmission kind of all of a sudden kick, enough to squeal the rear wheels.  Its kind of like there's some hesitation in acceleration and then it kicks in hard, but I don't see or feel the RPM's climb like I think I would if it was slipping.  I don't notice any transmission slipping, but I've always felt like the throttle on this model has been so unresponsive, it could be slipping and I might not know it.  

 

So, I called my mechanic today and asked him to check what ATF he used.  He checked and called me back saying it was a universal type fluid that says its good for Dexron VI (manual calls for Dexron VI).  I trust this mechanic, and he's been fair in the past.  He told me to bring it in and he would replace the fluid with ACDelco tomorrow at no charge.

 

I'll give everyone an update on if that solves the problem, but I also wonder if doing the flush could have uncovered a worn transmission.  I'm coming up on the 60k powertrain warranty, so I don't have too much time to wait and see.  So, my questions are 1) could a universal type ATF fluid that's labeled for Dexron VI be causing these problems? 2) Without feeling transmission slip, would these symptoms indicate a worn transmission? 3) Could this be a computer control issue where I should disconnect the battery to force a re-learn?

 

Hopefully this resolves itself, but if not I guess I'll have to be ready to take it to the dealer and have them diagnose it.  I'm not even sure how good they'd bee at diagnosing this since I could see them saying hard shifts are normal like they often like to tell everyone.  Oh, one other thing to note.  The fluid level looks right on to me, and when the fluid was changed, I was told the the old oil looked good.

 

[Tbounds]

I had my transmission flushed by non dealer , 60,000 miles 2012 gmc 5.3, as soon as it drove out the door started making awful noise and not shifting . 

long and short of it dealer and trans shop said by flushing system must have loosened something in trans and it got locked up in and required new trans or rebuild .

I learned with these newer trans don't mess with them period .

[Bash74]

There is alot of back and forth on this topic but here is my thought. If your fluid is still in decent condition and not burnt then a flush is ok. Now if old and burnt the caked on residue that is stuck in the transmission valve body comes dislodged and can get stuck in areas that can cause problems. So if real old or burnt then I just do a change if oil still ok then i do a flush. Now of course with any vehicle a flush might not do anything wrong to a trans with burnt oil but the possible is greater that I don't risk. This is just my thought and way of doing stuff.

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[Logan Lanfear]

1 hour ago, Jullian is not my name said:

So, I called my mechanic today and asked him to check what ATF he used.  He checked and called me back saying it was a universal type fluid that says its good for Dexron VI (manual calls for Dexron VI).  I trust this mechanic, and he's been fair in the past.  He told me to bring it in and he would replace the fluid with ACDelco tomorrow at no charge.

 

The whole no charge thing kinda makes me feel skeptical but...

He probably should have used the ACDelco in the first place but I dont think thats your problem.  

[garagerog]

Pan drop and filter change is the tried and true method of transmission maintenance when done in a timely and scheduled manner. Unless GM has changed there way of thinking they have never recommended a flush except for the lines to the cooler(s) if they become plugged, then you're looking at a rebuild anyway. A transmission flush is a profit center for dealers so they would like you to think that's what GM recommends, but not so. If you feel the need for a flush, make sure it's with Dex VI and never, ever a chemical flush, especially with high mileage transmissions.

[Grumpy Bear]

And the reason I just did a drop and fill with fluid I bought. 

[Obscenejesster]

And the reason I just did a drop and flush with fluid I bought. 

What is a drop and flush? Is it different than what the OP did?

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[Grumpy Bear]

11 minutes ago, Obscenejesster said:

What is a drop and flush? Is it different than what the OP did?

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Ops. Drop and fill. That's is drop the pan, change the filter and refill. (I corrected the original text, sorry for the typo and thanks for the catch). 

 

Standard service procedure. 

 

 

[15 Z71]

If you don't do alot if towing why would you change it? Manual recommends 100,000 miles. 

[Grumpy Bear]

50 minutes ago, 15 Z71 said:

If you don't do alot if towing why would you change it? Manual recommends 100,000 miles. 

https://en.wikipedia.org/wiki/Automatic_transmission_fluid

 

This link will inform you that ATF has the same 'types' of additives that motor oil does. Fact is the only additive ATF doesn't have motor oil does is antacid. 

 

I find it interesting that when it comes to the oil in your motor that no one recommends leaving it in your motor more than a year even if you didn't drive the car the entire year. Most have it at three months. There was even a push at one time to date motor oil and not use cans/bottles over one year old! The reason stated is...additives have a finite shelf life. Given the average 12,000 miles per year those in the USA drive that would be an ATF change once every 8.3 years. Your asked to purge your brake system more often than that and it is a closed system. Odd? Not really. Closed systems still draw moisture. No such thing as a perfect seal. 

 

One of two things becomes true. Either someone is lying about the rate of additive decay thus selling unrequired oil changes OR they are not and we are selling transmission overhauls. Pick one. They can't both be true. 

 

Secondly, for me anyway, the old adage "I'll change it when I can smell it's gone bad or it gets burnt"...means what? Means damage has already happened or it wouldn't be burnt and smelly. That one need more explanation? 

 

Thirdly,  as I have access to Group IV/V fluids and I know they offer an advantage over Group III fluids leaving the lower performing fluid in makes little personal sense. ACDelco Dexron VI fluid is a Group III. 

 

Lastly, the vehicle nor the person that might own it after me ever did me wrong and I can find no reason to dump a piece of junk on them nor mistreat my machine. I have no idea when I buy one how long it will serve me but serve it will. And it will do so without being a danger to me or anyone else if I can help it. 

 

I have no interest in GM or any manufactures marketing lust and as they can not seem to find the truth I will take my best crack at it. 

 

 

[TrueBlueSilverAdo]

hey guys, unless you have trucks that are doing severe duty, the handy book in the glove box says not to do it till 100k.

never believe what the dealer says. Always look at the book for the vehicles recommended maintenance

[mookdoc6]

Grumpy bear says, "Closed systems still draw moisture. No such thing as a perfect seal.  "  I agree 100% that is why I find it interesting that 20yrs ago NEVER was a mention in Big Three manuals to change your brake fluid?  Actually, nobody ever did unless you blew your master seal out and had no choice.............

 

As for TrueBlueSilverAdo.....I think your handy little book in the glove box says, 8L90 says well nothing?  Other than change it @5years.....yeah, OK you can follow your handy dandy little Book........

 

I forgot to mention I live in Phoenix, AZ and drive 30K a year so that would be...ummmm 150K pounding Heat,stop and go etc....Ok, I will wait until 150K glad I have that little book to help me along...

[Jullian is not my name]

So here's my update.  I took it back to my mechanic this afternoon, they used their flushing machine to replace all 12+ quarts of ATF with ACDelco Dex VI.  They took it for a quick test and then handed it back over to me.  So far I've only driven it about 15 miles back to work, but it feels better so far.  No hard shifts and I would say its shifting tighter with less lag.  It's still a little too early to tell for sure, as the tranny was up to temp when I drove it, and the shifting problems were more noticeable when it was cold.  At the very least, I can be pretty sure that the transmission has been flushed pretty well, so hopefully that cleared any crap that may have been causing problem.  I asked if they use a solvent when flushing, and thankfully he was aghast at the idea and said no way, they just use clean ATF run through to replace the old fluid.  So, fingers crossed that this clears things up.  I'll try and post another update after at least a few more days.

 

I've read a lot of the discussion on whether to flush or not, and I've talked to my GM service advisor on this topic too.  Like a lot of others have said, they still advice doing a flush if you do it early, and otherwise just a normal drain if your miles are getting up there.  I'm sure not an expert to say which is right, but I'll probably do another flush at 100k miles.

[tnchevy]

I would NEVER do a flush on a transmission, too many people have had problems after doing this.  The idea is that the force of the flush may loosen up and or force metal fragments in places they shouldn't be.  I have always just done the pan drop and filter change every 30k miles on every truck I have owned and I keep them for 10+ years and 150k+ miles and never a problem doing it that way.  You don't get all the fluid out doing the pan drop method but enough fresh is put back in too keep the transmission happy.

[mookdoc6]

This flush is performed using the Transmission's internal pump....so there should be no FLUSHING per say it's replacing fluid...........The same came be said, "I spun a bearing right after the oil change?"  More misconceptions and fallacies on the street!