Is 8-speed transmission now good?

[SilveradoRST]

Sorry to harp on this, but you fellas with '19 New body -'22 LTD 8 speeds, none of you are experiencing the first shift of the day slip/clunk from 1 to 2?  

 

I know it is a known issue, GM says it is because the clutch is being filled after draining overnight.  But I'm starting to feel like I'm experiencing the slip/clunk more than anyone else here.   

[ESierra]

1 hour ago, SilveradoRST said:

Sorry to harp on this, but you fellas with '19 New body -'22 LTD 8 speeds, none of you are experiencing the first shift of the day slip/clunk from 1 to 2?  

 

I know it is a known issue, GM says it is because the clutch is being filled after draining overnight.  But I'm starting to feel like I'm experiencing the slip/clunk more than anyone else here.   

Sure sometimes it hard shifts from 1 to 2 but it doesn't bother me. Once it's warmed up it's solid. I've actually noticed it stop "hard" shifting when I got bigger heavier tires. Lol

[4banger]

no hard shift for me, 3000 kms now, 22 2.7

[mjr15197]

I had the hard shift in the morning but otherwise had no complaints until last night.  I was lucky to be able to drive it back to the dealer.  It started downshifting hard on its own and stayed in about 2nd gear.  It threw codes P0700, P0717, P0776, P0796.
'21 Silverado 2.7. 21k miles.  

Edited July 14, 2022 by mjr15197
added more codes

[winks79]

19' Sierra with 43k miles. Dealer did fluid flush and change around 5k miles. Been fine ever since. 

[SteveCZ]

On 7/11/2022 at 1:11 PM, SilveradoRST said:

Sorry to harp on this, but you fellas with '19 New body -'22 LTD 8 speeds, none of you are experiencing the first shift of the day slip/clunk from 1 to 2?  

 

I know it is a known issue, GM says it is because the clutch is being filled after draining overnight.  But I'm starting to feel like I'm experiencing the slip/clunk more than anyone else here.   

I can't comment on the 8 speed shifts, as I have a 10 speed, however, I'm curious on your morning start up.  Do you start the truck, let it come down from high idle, and settle in, then drive away, or do you start the truck cold, then immediately put it in reverse and drive away?

 

Wondering if the truck just needs a few seconds to get itself sorted.  Just brainstorming.....

[Silverado4x4]

1 hour ago, SteveCZ said:

I can't comment on the 8 speed shifts, as I have a 10 speed, however, I'm curious on your morning start up.  Do you start the truck, let it come down from high idle, and settle in, then drive away, or do you start the truck cold, then immediately put it in reverse and drive away?

 

Wondering if the truck just needs a few seconds to get itself sorted.  Just brainstorming.....

If I get in and start the truck without letting it idle down I will get the hard reverse bump but that goes with any trans, it high idles at about 1100 rpm then down to 600 rpm or so it is smooth but like I said earlier since they changed it to the updated fluid its smooth as butter on the 1st-8th shifts. When I first start the truck cold I will let it idle down which only takes about 20 seconds when cold. Yes the truck does need a few seconds to sort itself out on a start cold or warm.

Edited July 15, 2022 by Silverado4x4

[SilveradoRST]

1 hour ago, SteveCZ said:

I can't comment on the 8 speed shifts, as I have a 10 speed, however, I'm curious on your morning start up.  Do you start the truck, let it come down from high idle, and settle in, then drive away, or do you start the truck cold, then immediately put it in reverse and drive away?

 

Wondering if the truck just needs a few seconds to get itself sorted.  Just brainstorming.....

I let it come down from the high idle before I drive.  I even let it idle a little longer than I should sometimes when the family is being loaded in.  If I drive out of my neighborhood around 30-40km/h (speed limit on neighborhood street is 40) normal gradual acceleration, I’ll get a high rev and then jerk into 2nd but only the first 1st to 2nd.  However, if I drive extra slow, 10km/h or so? to ease/crawl into that first shift from 1st to 2nd , I can avoid the jerk.   And after that all shifts are fine.  Even the next 1 to 2 is fine.  
 

It’s summer here, we’re around 27C, sometimes 33C.  In the winter I do the same, high idle takes longer to come down but no difference in behavior after that.  
 

Had the new fluid exchanged, the shifts were tighter afterwards but that 1-2 is still there.  GM issued a TSB saying it was a “known issue”, but it seems like a “no issue” for most people here.  Lucky me.  

[Peter land]

On 7/7/2022 at 10:53 PM, Interleukin6 said:

My 2019 4.3L with 6-speed transmission was a total loss last week. I need a new (Custom trim). Now only see 2.7T paired with 8-speed transmission. As far as I know, GM 8-speed transmission has been infamous, facing class action lawsuit. Is this only affecting to ~2019 model year or current model too? 2.7T also reliable? Thank you. 

The latest 8 speeds is way better never heard any issues yet.  

[Texcl2]

I have an updated 2022 2.7ho trailboss I have 3500 miles on it. When it was new it would have a little clunk going into 1st from a hard stop. I took it in to the dealer and they checked it all out and said it would be learning for the first few thousand miles and not to worry about it as it would go away as it learned. Sure enough it did. Now it’s smooth as butter. Love the 2.7ho fyi. I drive 5.3’s at work and both feel about the same power wise.

[ESierra]

I drive a ton of miles in this truck (25k per year nowadays), I usually let the truck idle for about a minute before moving. I've done that with pretty much every car/truck I've ever owned. I do sometimes feel like the transmission is confused in first gear, when idle. I do feel a slight rumble in the cab, I think that is due to the truck trying to do cyl deactivation. I've never seen a CEL on, so there is no point in paying for the Dealership to look at it. (Ironically, turning it off and on again disappears that)

 

I've thought about doing a automatic transmission fluid flush when I see about 50k miles. Not sure the dealership costs, but if it's within reason I'll do it due to driving it so often. I keep referring to the manual, but it doesn't look like much needs to be done until the spark-plugs. 

[Black02Silverado]

1 hour ago, ESierra said:

I drive a ton of miles in this truck (25k per year nowadays), I usually let the truck idle for about a minute before moving. I've done that with pretty much every car/truck I've ever owned. I do sometimes feel like the transmission is confused in first gear, when idle. I do feel a slight rumble in the cab, I think that is due to the truck trying to do cyl deactivation. I've never seen a CEL on, so there is no point in paying for the Dealership to look at it. (Ironically, turning it off and on again disappears that)

 

I've thought about doing a automatic transmission fluid flush when I see about 50k miles. Not sure the dealership costs, but if it's within reason I'll do it due to driving it so often. I keep referring to the manual, but it doesn't look like much needs to be done until the spark-plugs. 

I highly suggest you have the transmission serviced at 50k  I do that to all my vehicles.  You of course will be doing more often then the average person since you put the miles on so fast, but if you plan on keeping the truck I would recommend it. 

[diyer2]

Service the trans every 50 K with Amsoil fluid, you'll be glad you did. 

[customboss]

Which fluid did you change to?   I was starting to get what I would call 1/2 cold notchy shifting with the Mobil1 HP after 12,000 miles. I am rough on it in 4WD on really rough roads at crawling speeds so driveline is really working. 

 

Had my 2022 LTD Trail Boss w/2.7T 8 spd changed out via BG machine at dealer for Amsoil ATL vs the Mobil1 HP @ 13741 miles on unit  and its noticeably better shift  up and down.   I climb and descent  10,000' msl mountains pass frequently I haven't seen ATF temp above 214F and yesterday it was 100F at start of pull at 10,000 peak it was 88F on truck temp sensor.  Thats smokin hot in thin air. No good heat dissipation. 

 

15000 almost now on it will keep you informed how its working.  

 

 

 

 

 

On 7/15/2022 at 10:02 AM, SilveradoRST said:

I let it come down from the high idle before I drive.  I even let it idle a little longer than I should sometimes when the family is being loaded in.  If I drive out of my neighborhood around 30-40km/h (speed limit on neighborhood street is 40) normal gradual acceleration, I’ll get a high rev and then jerk into 2nd but only the first 1st to 2nd.  However, if I drive extra slow, 10km/h or so? to ease/crawl into that first shift from 1st to 2nd , I can avoid the jerk.   And after that all shifts are fine.  Even the next 1 to 2 is fine.  
 

It’s summer here, we’re around 27C, sometimes 33C.  In the winter I do the same, high idle takes longer to come down but no difference in behavior after that.  
 

Had the new fluid exchanged, the shifts were tighter afterwards but that 1-2 is still there.  GM issued a TSB saying it was a “known issue”, but it seems like a “no issue” for most people here.  Lucky me.  

[customboss]

BTW my dealer charged me $87 for the BG trans fluid machine exchange. 13 qts Amsoil ATL and I will probably do it again around 50-60,000 miles to maintain that performance. 

 

 

Edited July 20, 2022 by customboss
add brand of ATF that is working better than OEM