Who likes their 8 Speed?

powerhaulic · November 2, 2016

Hello all this is my first post here. I found and joined this site due to my ongoing issues with my 8 speed. It's been bad since the ride home from dealer. I had the converter replaced at 700 miles. That took care of the shuddering but I'm still left with awful shifts up and down. Only occurs when driving smoothly. Truck has 3700 miles on now and seams to be getting worse. Fuel milage is down too. Truck is 100%stock. Towing and leaning into it is awesome. Truck is a rocket ship. Dealers have been no help. "OPERATING AS DESIGNED" is what I get. No updates as of yet. Gm customer service sas bring it to dealer. Well after 10 new gm cars and trucks in past 15 years between me and my wife im little disappointed. Please help gm. I know it's in the programming. I myself am an nissan dealer mechanic. Nissan has similar issues that are usually repaired timely and simply with reprograms. Seams this issue spans years of production. What's going on,???

Where in ny are you?

silver sled 16 · November 3, 2016

Suffolk county long island

Snoringbear · November 3, 2016

Hello all this is my first post here. I found and joined this site due to my ongoing issues with my 8 speed. It's been bad since the ride home from dealer. I had the converter replaced at 700 miles. That took care of the shuddering but I'm still left with awful shifts up and down. Only occurs when driving smoothly. Truck has 3700 miles on now and seams to be getting worse. Fuel milage is down too. Truck is 100%stock. Towing and leaning into it is awesome. Truck is a rocket ship. Dealers have been no help. "OPERATING AS DESIGNED" is what I get. No updates as of yet. Gm customer service sas bring it to dealer. Well after 10 new gm cars and trucks in past 15 years between me and my wife im little disappointed. Please help gm. I know it's in the programming. I myself am an nissan dealer mechanic. Nissan has similar issues that are usually repaired timely and simply with reprograms. Seams this issue spans years of production. What's going on,???

I've got the 6.2/8 spd combo. I was having problems with tranny making a hard shift when up shifting from 1st to 2nd when taking off from a stop sign and such. And, the same thing when down shifting when slowing down to stop. Didn't happen very often but enough to be irritating. So, when I took it in for an oil change brought it up with the service rep. When I picked it up GE said they ran all the codes and nothing showed. But, he also said that they reset the tranny back to factory settings so it would go through the relearn procedure. That helped a bunch. Problem now shows only occasionally, usually when it's cold during the first start up for the day. But, as you, this rig shows its stuff when under a load such as towing and I'm as you put it, leaning into it. Pulls my 6,000 lb TT as though it wasn't even hooked up. When towing, open my bag of pig skins, pop a soda, set the cruise, then sit back and enjoy the ride

RobDarden · November 3, 2016

I have a 2016 Camaro with the 6.2 and 8 speed. It's awesome. Fastest,smoothest shifting tranny I've experienced.

Edited November 3, 2016 by CamaroLegend

silver sled 16 · November 4, 2016

When i had it in at 700 miles they replaced converter and reset self learn values. It was outstanding for first 1000 miles. Since then it has been getting progressively worse. Maybe delete self learn? I tried the whole disable the grade braking thing today. A little better. Ive Called gm to see if there's any updates. They said to bring it in for diag. I have appointment with dealer Monday. I will post all results. I know there are a lot of people that read and move on. I myself have been one of them. I've been reading this site for quite some time soaking up experience and knowledge. I figured it was time to give back. I'm happy to see that a lot of people here love their trucks/transmissions. Gives me hope for mine. I wish I had some cool trick or update to share rather than this transmission problem. Thanks to all who have posted. It's been a enlightening experience.

Edited November 4, 2016 by silver sled 16

LiveToRide · November 4, 2016

2016 Sierra SLT All Terrain with a 5.3 and 8 speed. Bought in September, now has 2200 miles and shifts great. Towed a couple of four wheelers in tow mode twice with no issues. Don't know that the Sierra is quite as smooth as my old Tundra, but it's close.

SkiDooNick700 · November 6, 2016

I was just in a 80 mile trip of city and highway in a Ecodiesel with the 8spd. That trans didn't have a single hiccup.

Im just not totally satisfied with my 8spd. After 20k miles I still have jerky shifts especially gears 1, 2, 3, and 4 both up shifting and even downshifting such as braking for a red light. Sometimes the jerk overpowers the amount of brake Im applying.

Id like to drive another GM 8spd truck to compare it to mine.

Croak · November 6, 2016

That is converter shudder

Occurs light throttle light load.

I'm thinking the additive package in the new spec Dexron HP is greatly at fault, combined with software....JMHO

Is there any documentation out there regarding converter shudder that I could point out to the dealer? Cause when we went for the test drive it had stopped shuddering but was still slipping and the guy didn't think it was a trans issue. Said I would have seen it before now - all the problems they've seen with 8 speeds have been "clutch packs, other internals, and they all happen early. No converter issues, especially not after 26,000 trouble free kilometres". Recommended a few things to check (he seems to be under the impression it's 'normal behaviour with variable load from things coming on and off like the a/c compressor') and said if that didn't fix it then to come back since I have plenty of powertrain warranty left. I didn't push the issue too hard since my truck is lowered and straight-piped and I don't want to get into a warranty pissing-match unless I have to.

flasch192 · November 6, 2016

I gave it and gm a shot, the 2nd Trans got so bad with hard shifts late shifts and shift flares plus fuel mileage was down alot , just hated driving it , traded it in and back in a f150 .........

Dmf10e · November 7, 2016

I have the 6 speed 4.3L V6 and have the same shifting issue, so it's not just with the 8 speeds. It's extremely annoying more than anything else. Love the truck though. When I first bought it, it did not have this issue. Was probably because it was still "learning." Hoping it eventually will get better. Dealer says it's normal.

silver sled 16 · November 8, 2016

Had my truck in yesterday for trans issue. At write up in was told it was normal and that they would probably not find anything. Well after 24 hours you guessed it. They didn't find anything wrong. However they did supposedly reprogrammed the tcm.. when I asked for a cal i.d. number or bulletin number they told me that was private gm info. Long story short truck was clunking on the way home. They put zero miles on the truck while they had It. Pretty sure they just moved it from one parking spot to another.

powerhaulic · November 8, 2016

Had my truck in yesterday for trans issue. At write up in was told it was normal and that they would probably not find anything. Well after 24 hours you guessed it. They didn't find anything wrong. However they did supposedly reprogrammed the tcm.. when I asked for a cal i.d. number or bulletin number they told me that was private gm info. Long story short truck was clunking on the way home. They put zero miles on the truck while they had It. Pretty sure they just moved it from one parking spot to another.

You need a new dealer........

silver sled 16 · November 8, 2016

This truck has been to 2 of the 3 local gmc dealers in my area. It seams they don't want to admit there's an issue and get involved with a buy back. Technicians all admit they experience an issue with the truck but there's no fix and throwing transmissions and releans at it does nothing. The 3rd dealer flat out refuses to take it in due to the fact I didn't buy it there. I love this truck. It's such a shame with this transmission. Guess I gotta seek legal help.

Snoringbear · November 9, 2016

Well, sitting here reading my latest Truck Trend magazine and came across the below article. The TT testers raved about how fantastic the truck is, smooth (no Chevy Shake mentioned) and flawless the truck performs "except" for a occasional hard ka-chunk when shifting. Thought I would share their comments about it.

http://www.trucktrend.com/truck-reviews/1609-2016-gmc-sierra-1500-denali-long-term-report-1-of-4/

silver sled 16 · November 9, 2016

Wow snoringbear. Thank you. I will be forwarding this article to gm and bbb. They keep telling me there's nothing wrong. As designed. Well if that's the case I can't understand why they would design it to clunk and bang. Seams like it wouldn't last very long or the u joints or rear axle for that matter.