2017 harsh low speed shifting

Poffdaddy · November 6, 2017

I have posted on here before. I thought maybe someone might have some new insight. I have the classic 8 speed shifting terribly like the transmission is going to drop out at low speeds. It is an ltz 6.2 crew cab 4x4. I had the relearn tsb done at about 2000 miles although I really doubt the technician actually went and drove it after based on the amount of miles put on it at the dealership. I don't think it ever really made it better. They gave me all the crap about how it will learn how I drive blah, blah, blah. Well I have 10,500 miles and it still hasn't learned how I drive because it does it almost every time driving through parking lots. I haven't read one thing anywhere that says there has ever been a permanent fix. I am going to take it back and ask how many miles is it supposed to take to nor make that horrible hard shift anymore. With the 10 speed transmission coming up I'm sure at this point gm doesn't care about really fixing it. Maybe it is stout and will last 200k miles but it sounds terrible. The only thing I can think to do now is drive it another year or so until I'm ahead on it and then get rid of it. Anybody know how many miles it will take before it learns how to not destroy itself?

Sir Dan · November 10, 2017

Try driving the truck with trans in M7 when running stop lights or parking lots. This disables the AFM and makes the throttle response and shifting a bit smoother in my opinion. Mine is WAY worse when the truck is cold. If I try to take off right away without waiting about 10 seconds with it in D, it will rev up and jump into the next gear with a bang. Mine will be traded off very soon due to sh**ty trans and weird shaking above 70mph. Love the truck but hate, hate, hate this 8 speed! Haven't they been building auto transmissions for many decades? How could they Eff one up so badly like this?

benelli · November 10, 2017

On 11/5/2017 at 9:57 PM, Poffdaddy said:

I have posted on here before. I thought maybe someone might have some new insight. I have the classic 8 speed shifting terribly like the transmission is going to drop out at low speeds. It is an ltz 6.2 crew cab 4x4. I had the relearn tsb done at about 2000 miles although I really doubt the technician actually went and drove it after based on the amount of miles put on it at the dealership. I don't think it ever really made it better. They gave me all the crap about how it will learn how I drive blah, blah, blah. Well I have 10,500 miles and it still hasn't learned how I drive because it does it almost every time driving through parking lots. I haven't read one thing anywhere that says there has ever been a permanent fix. I am going to take it back and ask how many miles is it supposed to take to nor make that horrible hard shift anymore. With the 10 speed transmission coming up I'm sure at this point gm doesn't care about really fixing it. Maybe it is stout and will last 200k miles but it sounds terrible. The only thing I can think to do now is drive it another year or so until I'm ahead on it and then get rid of it. Anybody know how many miles it will take before it learns how to not destroy itself?

I have a 2017 sierra. I traded in my 2014 Ram 1500. One of the biggest mistakes of my life with trucks. Reason i traded could not get used to the knob shifter in the ram. Anyway since new this sierra 200klm this POS shifts like a farm tractor. turning into a parking spot then reversing and back into drive as i pull away seems like someone rear ended you. took it to the dealer twice. first time service guy says needs an update. then i pick it up leaving parking lot bangs into second again. come back a week later service guy call out the tech he comes for a ride with me. soon as he gets in says to me these transmissions from gm the 8 speeds are Shit Junk exact words. says people with 100,000k Denali`s and escalades have same issues. they cant do anything because its a gm software isssue and gm wont release a fix because it screws with there fuel economy they want these trucks to go through all the gears from one stop sign to the next and keep the rpms low for fuel economy this way they get better kick backs from the government. anyway i have been on the phone with GM canada so called ambasators. some fancy name for an idiot behind a desk that took some course on how to calm down customers when they call in about there 60,000 vehicle running like crap. there usless. i will make it my mission to take this truck in every week till i trade it up for them to fix this junk. i got the time this winter. I will update everyone as i go along. going in Monday for the first round. the only good thing at my dealer is the espresso machine.

CDNSS · November 11, 2017

I had sumilar issue eith my 2017 6.2 8 spd at about 5km. Took it in had the TSB relearn done Works great !! Got better the more I drove it over thst week the now at 10k working great

your right tech said no GM absolute fix but there are more than one TSB for this issue mine was to correct the delay engaging gear when cold but also fixed the shifting issue I think it was 416 for corvette but

Poffdaddy · November 11, 2017

Benelli,

At 100k issues and still having same issues I hope it is just a software issue and not a mechanical issue. I would be less concerned if it's only software. If I decide to keep it for the long run I could get an after market tuner to fix it although I shouldn't have to. Does anyone know if the transmission is actually mechanically sound and will actually go at least 100k without exploding? I thought this would be a vehicle I would keep for 200k but I'm concerned for sure. Does anyone know of any 8l90 transmissions with high mileage and no breakdowns? If it doesn't get better I'll drive it another year or two until I'm ahead and then trade it for a ford or maybe a new generation tundra by then.

Poffdaddy · November 11, 2017

2 hours ago, CDNSS said:

I had sumilar issue eith my 2017 6.2 8 spd at about 5km. Took it in had the TSB relearn done Works great !! Got better the more I drove it over thst week the now at 10k working great

your right tech said no GM absolute fix but there are more than one TSB for this issue mine was to correct the delay engaging gear when cold but also fixed the shifting issue I think it was 416 for corvette but

Did they just do the relearn TSB on yours? I have 11000 on mine but still get rough shifts. It is less but they are still there.

Poffdaddy · November 11, 2017

Does anyone know about a triple flush and filter replacement to fix rough shifting? Do they put in different fluid than original spec?

mnm99 · November 12, 2017

I just got back from my first oil service at 5000K. I told the dealer about how crappy it downshifts at low speeds. He told me GMC is aware and that is NORMAL...WTF..He told me there was a bulletin on this too. Maybe I'll stop by and get it. I'll post it here. As the other poster noted. I also had a Dodge Ram. It was a 2003 I bought new and shifted perfect from the day I bought it. I sold it with 93K. I plan on keeping this just as long as my ram , but am worried the rear will fall out before then...

CDNSS · November 12, 2017

On 11/10/2017 at 9:32 PM, Poffdaddy said:

Did they just do the relearn TSB on yours? I have 11000 on mine but still get rough shifts. It is less but they are still there.

Yes a clutch relearn 16-na-364. This for delayed gear engagement after sitting but it also cleaned up the rough shifts and got even better after week. I do drive agressively occasionally to keep trans learned

Largely Unknown · November 12, 2017

Does anyone have the TSB issue date? Mine was built in June. I have 1K miles (our in October). I'm just trying to determine if there is a TSB that applies to certain dates of manufacture.

It's a 5.3L, 8 speed and is fairly smooth except for starting out cold, and the occasional surprise slightly-hard shift at low speed.

I'm generally happy with it, although I have yet to understand its programming and how to best drive it. The used lot at my dealer has a number of 16's with the 8-speed. I noticed this - hmmm - but maybe they're program cars or something.

Thanks

benelli · November 13, 2017

On 11/10/2017 at 10:33 PM, Poffdaddy said:

Does anyone know about a triple flush and filter replacement to fix rough shifting? Do they put in different fluid than original spec?

Tech at Gm told me the triple flush and fill with Mobile 1 HP is what is required on the ealier models because GM used the wrong fill for transmission from Factory. Straight from the transmission Tech.

benelli · November 13, 2017

12 hours ago, mnm99 said:

I just got back from my first oil service at 5000K. I told the dealer about how crappy it downshifts at low speeds. He told me GMC is aware and that is NORMAL...WTF..He told me there was a bulletin on this too. Maybe I'll stop by and get it. I'll post it here. As the other poster noted. I also had a Dodge Ram. It was a 2003 I bought new and shifted perfect from the day I bought it. I sold it with 93K. I plan on keeping this just as long as my ram , but am worried the rear will fall out before then...

I hear you Brother. My 2014 Ram shifted great. Gm tries to blow smoke up peoples a**** and tell you its normal. Thats why so many Gmc`s And silverados on the used car lot. People are sick and tierd of 60,000 POS. Unless the transmission is unsafe they wont do anything just string you along till your tierd.

Poffdaddy · November 13, 2017

35 minutes ago, benelli said:

Tech at Gm told me the triple flush and fill with Mobile 1 HP is what is required on the ealier models because GM used the wrong fill for transmission from Factory. Straight from the transmission Tech.

How do they miss something like that? Rediculous. Do the 2017's have the correct fluid in it?

Poffdaddy · November 13, 2017

1 hour ago, Largely Unknown said:

Does anyone have the TSB issue date? Mine was built in June. I have 1K miles (our in October). I'm just trying to determine if there is a TSB that applies to certain dates of manufacture.

It's a 5.3L, 8 speed and is fairly smooth except for starting out cold, and the occasional surprise slightly-hard shift at low speed.

I'm generally happy with it, although I have yet to understand its programming and how to best drive it. The used lot at my dealer has a number of 16's with the 8-speed. I noticed this - hmmm - but maybe they're program cars or something.

Thanks

I'll bet all those used ones on the lot really increase the resale value. That should make it much easier to get rid of this thing in a year or two when I'm ahead on it. This is the first new pickup I've purchased. I'm not a brand enthusiast so I really doubt my next pickup after this one will be a gm product.

Poffdaddy · November 13, 2017

31 minutes ago, benelli said:

I hear you Brother. My 2014 Ram shifted great. Gm tries to blow smoke up peoples a**** and tell you its normal. Thats why so many Gmc`s And silverados on the used car lot. People are sick and tierd of 60,000 POS. Unless the transmission is unsafe they wont do anything just string you along till your tierd.

So by normal do they mean mechanically solid? Other than the rough shifting what will the long term reliability be like?