Who likes their 8 Speed?

JacobC1983 · August 13, 2017

I know the yukon denali and escalades were gettings the 10 speeds; I didn't think the Sierra Denali was getting it until 2019 with the redesigned trucks

wildlyfe200 · August 13, 2017

I know the yukon denali and escalades were gettings the 10 speeds; I didn't think the Sierra Denali was getting it until 2019 with the redesigned trucks

From my research no Sierra, Denali or not is not getting 10 speed in 2018 yukon yes.

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Snoringbear · August 15, 2017

This is exactly what Mercedes does on the 7 speed in the S550. Pulls from a stop in second gear. Now if you put it in sport mode it starts in 1st gear. But all normal driving even very slow it doesnt drop to 1st unless you floor it. And it's smooth and always in the right gear, so GM could do it as it is just in the tuning. The just wont do it! Now I fear they are abandoning the 8 speed which I like for alot of other reasons, especially towing. The 2018 Denali is getting the 10 speed.

Interesting. I wonder if it would be possible for one of those tuner outfits to design a program to do the same thing for 2014 ~ 2018 GM eight speed tranny? I once the application is understood it probably would sell....

mookdoc6 · August 15, 2017

Interesting. I wonder if it would be possible for one of those tuner outfits to design a program to do the same thing for 2014 ~ 2018 GM eight speed tranny? I once the application is understood it probably would sell....

Yeah, could be of use.....The 10speeds will be skipping on the way up and down during it's shifting. That would be cool to be slamming from 1st to 3rd with 8K behind you than having that load slam and push you after the Tranny just Jerked ya! Can't wait...........

Edited August 16, 2017 by mookdoc6

JacobC1983 · August 15, 2017

Yea - they better get the programming in the 10 speeds right.

From what I have been reading over on the Ford forums.... they are already having some issues and failures with the 10 speeds.

Silverado1500HighCountry · August 18, 2017

Shifting is awesome no problems so far.

seamus2154 · August 19, 2017

Yea - they better get the programming in the 10 speeds right.

From what I have been reading over on the Ford forums.... they are already having some issues and failures with the 10 speeds.

I was just in my dealership talking with three upper managers while buying my 2017 Denali, experssing I hope this 8 speed is improved. One said he was talking with a master tech who was on the line with GM regarding an 8 speed issue. He said they were improved quite a bit since their debut but still had complaints and issues although alot less. The GM guy on the phone said if they were having fun with the 8 speed, brace and get ready for the 10 speed because it should be a mess in its infancy due to many "new" designs internally. Never buy GM in the first 2 years of anything new is what I have learned.

Dnt · August 20, 2017

Got an appointment with my local Buick GMC dealership to do my first oil change / rotate tires and "hopefully" FIX the clunky transmission on Monday (ECLIPSE DAY),

My Clunky 8spd Trans seems to be getting worse. When first started in the morning and putting into reverse it SLAMS into gear, at almost every slow roll coming to a stop it SLAMS into a lower gear really feels like someone hit the back bumper. It hunts for gears at low speed like it has no sense at all. Totally unacceptable. Makes me wish I had my 2016 6.2 8spd back. The 2016 only had a rare event of harsh downshift once in a while, this 2017 is Ridiculous. Will try to remember to report back. They will fix this or I will be driving a different truck in a few weeks. I am not going to put up with BS on a +64k sticker vehicle....

seamus2154 · August 21, 2017

There are TCM updates. They did one on my 2015 it was a big difference. Then I had the stator shaft done and they did another update which sucked and pretty much fixed my delayed engagement but it shifted like hell again. So I am certain this is all tuning. Either way I traded into a 2017 and so far I am very happy with the trans.........only 500 miles though!

cjhrph · August 25, 2017

Happy here as well.

Not me. 2017 here. 6.2/8 Sp. Same issues. LOVE the truck and the 6.2, transmission is possessed at low speeds, turning, coming to a stop etc. Clunks, Harsh Downshifting, Surging. No problems when your on the gas though, impressive, smooth as silk. Just had TCM update from the PIP5437B bulletin applied at 600 miles. Not sure it did much. Ill give it short to while to "re-learn".

Dirt-Rado · August 25, 2017

17' 6.2L/8sp 7800 miles

It hasn't gotten any better but I wouldn't give up my 8 speed.

18MPG towing a 24' boat is unheard of in any other vehicle I've owned.

Clunks and surges but at speed it's great.

Curious how it'll do in the sand dunes off road.

I'm convinced once everyone cracks the codes to tune these things we should see an improvement.

mookdoc6 · August 25, 2017

17' 6.2L/8sp 7800 miles

It hasn't gotten any better but I wouldn't give up my 8 speed.

18MPG towing a 24' boat is unheard of in any other vehicle I've owned.

Clunks and surges but at speed it's great.

Curious how it'll do in the sand dunes off road.

I'm convinced once everyone cracks the codes to tune these things we should see an improvement.

Needs more time....8speeds take forever to settle down.....Flush the Trans it will help immensely too!

Dirt-Rado · August 25, 2017

Needs more time....8speeds take forever to settle down.....Flush the Trans it will help immensely too!

Good to know. Seems like when I drive it hard, it gets more aggressive and smoother. Still tough to break tires loose from a stop without brake standing. Others say it'll burn em up no prob but I drive fairly conservatively on a daily basis. What did you fill your trans with after the flush?

mookdoc6 · August 25, 2017

Good to know. Seems like when I drive it hard, it gets more aggressive and smoother. Still tough to break tires loose from a stop without brake standing. Others say it'll burn em up no prob but I drive fairly conservatively on a daily basis. What did you fill your trans with after the flush?

Yeah, the whole driving conservatively is why it's taking you and myself probably forever.....It almost seemed purposeful to me like hitting 10K better....20k...better..25K...wait it's really smooth now...35K and wake up drive and all that crap @ 5K is history? I did flush and fill it @ 18K with the AC-Delco HP @ a dealership and it helped hugely!

To me the thing is a absolute beast! IT loves being slammed? It never skips a beat and is smoother than anything floored up a decent grade? Than go down the other side and it holds speed and RPM's and goes down the hill like a STUD! Very Impressed with the downhill!

Try taking the battery off.....Let it sit couple hours hook it back up? Eventually, it will get better I have been where you are......

seamus2154 · August 26, 2017

17' 6.2L/8sp 7800 miles

It hasn't gotten any better but I wouldn't give up my 8 speed.

18MPG towing a 24' boat is unheard of in any other vehicle I've owned.

Clunks and surges but at speed it's great.

Curious how it'll do in the sand dunes off road.

I'm convinced once everyone cracks the codes to tune these things we should see an improvement.

Couldnt agree more. I just traded into the 2017 6.2/ 8 speed and can say this is much better than my identical 2015 setup. It isn't perfect but better. I agree in town driving, parking lots, and slow is where the issues are. Which is just tuning. Because off the light in a straight line it shifts perfect. Towing is where it really shines. Dropping to just 7th or 6th is so smooth and a pleasure towing. I have gotten 15 mpg towing at almost 80 mpg on flat roads here in Fla. Done even better at 70 mph. That is diesel towing mileage if not better. Don't know why but it is true the more you beat on it the better it shifts?