Who likes their 8 Speed?

[Srode1]

I have had a loaner 2017 Z71 5.3 6 speed 2 days while the dealer is doing service and a minor warranty fix and I can sure tell the power difference in casual driving between the 5.3 6 speed and the 6.2 8 speed. the 6 speed has a firmer shift that I expected compared to the 8 speed when it's behaving and the extra time in each gear is very noticeable when accelerating. Also surprised in the ride difference between the Z71 and my LTZ with the national tow package suspension, noticeably firmer in the Z71 (both crewcab short beds)

[mookdoc6]

I have had a loaner 2017 Z71 5.3 6 speed 2 days while the dealer is doing service and a minor warranty fix and I can sure tell the power difference in casual driving between the 5.3 6 speed and the 6.2 8 speed. the 6 speed has a firmer shift that I expected compared to the 8 speed when it's behaving and the extra time in each gear is very noticeable when accelerating. Also surprised in the ride difference between the Z71 and my LTZ with the national tow package suspension, noticeably firmer in the Z71 (both crewcab short beds)

So after driving both which do you prefer and why? Thanks-Mook

[muhsfink07]

wait so they still make the 6 speed for 2017? that doesnt make any sense... I thought all V8 trucks were 8-Speeds now (not sure about the V6's)

['17 Sierra]

wait so they still make the 6 speed for 2017? that doesnt make any sense... I thought all V8 trucks were 8-Speeds now (not sure about the V6's)

They do still produce the 6spd for '17.

[muhsfink07]

wow well that goes to show how half a@@ed they developed the 8 speed with the new 10 speed coming out now...

[wetcoaster]

Here's what GM has to tell me after confirming that it shifts less than customers desire but functions as designed. I'm basically stuck with this truck until my equity is high enough to off load it. This will be my last GM purchase after a good run.

 

"While we regret our review with Preston GMC did not meet your satisfaction, we must respectfully reconfirm our position. We sincerely wish it were possible to resolve every concern to our customer’s complete satisfaction, unfortunately, this is not always possible. Please don't hesitate to contact us again if you have any additional questions. You are also welcome to return to the dealership for any other service inquiries."

 

So word to the wise, don't buy an 8 speed or any other vehicle without seeing if there are issues the manufacturer is not willing to resolve.

 

Sent from my SM-G903W using Tapatalk

[muhsfink07]

Wow that is total BS... would you consider getting a custom tune to smooth it out and void the warranty?

[wetcoaster]

I have HP tuners and have tuned my caddy but my caddy is a manual and I've not done any auto trans tuning before. I would be interested in getting a custom TCM tune because the warranty obviously means nothing anyways when it doesn't cover this issue.

 

Sent from my SM-G903W using Tapatalk

Edited March 4, 2017 by wetcoaster

[jdnjo]

Took my truck in overnight with all the TSB's for hard shift to local dealer. They spent the day with it and called GM. GM told them it was normal. They dropped the pan to check for anything and refilled with 8 qts tranny fluid. Seems a little smoother but still a little harsh when cold. Will try again if no improvement.

[muhsfink07]

Ugh this is so frustrating. I kind of want to make huge stink and make them address this. At least the two time tranny flush. That seems to help a lot. Although I am not sure why flushing it would help...

[Srode1]

So after driving both which do you prefer and why? Thanks-Mook

There's nothing wrong with the 2017 LT Z71 5.3 6speed combo, it's a nice truck, but the total package on the 2015 LTZ NHT 6.2 8 speed is just nicer. The Z71 just rides like a truck compared to the LTZ NHT which rides like a car (surprisingly) and the 5.3 6speed combo feels sluggish compared to the 6.2 8speed. Towing (which is the primary reason I have the truck) performance would be less than I want I'm sure, and it's just not peppy. I would rather have an occasional abrupt shift than deal with being under powered vs what I want. The shifting on it is marginally better, I did feel some of the same harsh shifts just not as extreme as with the 8 speed, but the Z71 only has 3200 miles on it also so don't know if it will improve or get worse with time.

Edited March 4, 2017 by Srode1

[Srode1]

I have HP tuners and have tuned my caddy but my caddy is a manual and I've not done any auto trans turn ingredients before. I would be interested in getting a custom TCM tune because the warranty obviously means nothing anyways when it doesn't cover this issue.

 

Sent from my SM-G903W using Tapatalk

The warranty will mean something if you need the tranny rebuilt down the road.

[wetcoaster]

The warranty will mean something if you need the tranny rebuilt down the road.

That would be a miracle considering the fact that both the dealer and GM care has issued and presented bulletins indicating that harsh shifting will not affect the longevity of the driveline.

 

Sent from my SM-G903W using Tapatalk

Edited March 4, 2017 by wetcoaster

[Srode1]

That would be a miracle considering the fact that both the dealer and GM care has issued and presented bulletins indicating that harsh shifting will not affect the longevity of the driveline.

 

Sent from my SM-G903W using Tapatalk

That doesn't mean something else won't lunch the tranny - things break, even transmissions that shift normally go out during the warranty period.

[wetcoaster]

That doesn't mean something else won't lunch the tranny - things break, even transmissions that shift normally go out during the warranty period.

If you drive an 8 speed and think it's normal and acceptable then you're lucky. My truck doesn't drive like a $55k truck should