How smoothly does your 6 speed accelerate?

[MichLakes]

I have a 2020 with the 5.3 6 speed 38k miles..  It’s always felt like it pulses in certain gears under moderate acceleration.  
 

I’ve wondered if this is normal?  It’s mild but I notice it.  
 

 

[diyer2]

Change the fluid is what I would try. 

I would recommend Amsoil. 

[Grumpy Bear]

13 hours ago, MichLakes said:

I have a 2020 with the 5.3 6 speed 38k miles..  It’s always felt like it pulses in certain gears under moderate acceleration.  
 

I’ve wondered if this is normal?  It’s mild but I notice it.  
 

 

 

Okay since the day you bought it. It still under warranty then. Have the dealer check it out with the scanner and make sure pressures and timing are correct. He'd be looking of internal leaks. Also, and If he will let you ride along ask when and it repeats to look at TIR. They feel soft if the timing is being pulled under increased torque situations. If it checks out then as @diyer2 notes. Your close anyway for a fluid change. AMSOIL ATF is a great product as is Red Line D6. 

 

[Rail Boss]

2019 Custom TB 5.3 6spd 27,000mi same problem especially when getting on the interstate, more noticeable with 500lbs or so in the bed. My experience as an auto mechanic makes me think its a fuel supply or pressure problem rather than a transmission problem, but guessing gets ya nowhere.  Keep me posted if you find anything. I am out of warranty by 8weeks, under by 9k mi, but seeing the dealer said no to covering my rear window leak under warranty, sure i'm on my own here too. Not a new problem, just never took it in for service because its a lease I had planned on trading in. Now i'm buying it so live and learn.

Edited August 15, 2022 by Rail Boss

[MichLakes]

On 7/18/2022 at 11:07 AM, Grumpy Bear said:

 

Okay since the day you bought it. It still under warranty then. Have the dealer check it out with the scanner and make sure pressures and timing are correct. He'd be looking of internal leaks. Also, and If he will let you ride along ask when and it repeats to look at TIR. They feel soft if the timing is being pulled under increased torque situations. If it checks out then as @diyer2 notes. Your close anyway for a fluid change. AMSOIL ATF is a great product as is Red Line D6. 

 

https://static.nhtsa.gov/odi/tsbs/2022/MC-10213032-0001.pdf
 

I wonder if that’s the issue.  

[Grumpy Bear]

4 hours ago, MichLakes said:

https://static.nhtsa.gov/odi/tsbs/2022/MC-10213032-0001.pdf
 

I wonder if that’s the issue.  

 

Worth a look. 

[MichLakes]

Dealer said everything is normal.  It may be a "shift flare" which is not an issue to be fixed.  The dealer also said a trans fluid replacement is not due until 70k miles.  My concern is I am at 58k.  Hopefully they documented my issue.

[s10dragracer888]

On 7/17/2022 at 9:24 PM, MichLakes said:

I have a 2020 with the 5.3 6 speed 38k miles..  It’s always felt like it pulses in certain gears under moderate acceleration.  
 

I’ve wondered if this is normal?  It’s mild but I notice it.  
 

 

I thought I was the only one. When I let off the pedal, and then get back on it, it acts like it has to shift back up into overdrive. It’s very odd to me. The old 4L60 didn’t have this issue. Also, the 6 speed shifts -lazily- for a lack of better words. I don’t even have 43,000 miles on it.

 

2020, 4.3, 6-speed

[s10dragracer888]

On 5/15/2023 at 11:40 AM, MichLakes said:

Dealer said everything is normal.  It may be a "shift flare" which is not an issue to be fixed.  The dealer also said a trans fluid replacement is not due until 70k miles.  My concern is I am at 58k.  Hopefully they documented my issue.

That’s odd. In the older manuals (before 2020), I recall every 35,000 miles. I had mine flushed after the second thermal bypass valve and the torque converter was replaced. Right at 30k.

[Grumpy Bear]

5 hours ago, s10dragracer888 said:

I thought I was the only one. When I let off the pedal, and then get back on it, it acts like it has to shift back up into overdrive. It’s very odd to me. The old 4L60 didn’t have this issue. Also, the 6 speed shifts -lazily- for a lack of better words. I don’t even have 43,000 miles on it.

 

2020, 4.3, 6-speed

 

That "Lazy" feeling it torque management. Ment to keep guy from fragging the box. It's not a failure issue, it's a factory state of tune issue. 2015 4.3, 6-speed. I find mine is always in the right gear at the right time. Converter is always on the money and in lock step with the AFM. Much of what you feel is the converter lockup and not a 5-6 gear hunt. It does that to prevent that hunt like the old T700-R used to. 

[s10dragracer888]

31 minutes ago, Grumpy Bear said:

 

That "Lazy" feeling it torque management. Ment to keep guy from fragging the box. It's not a failure issue, it's a factory state of tune issue. 2015 4.3, 6-speed. I find mine is always in the right gear at the right time. Converter is always on the money and in lock step with the AFM. Much of what you feel is the converter lockup and not a 5-6 gear hunt. It does that to prevent that hunt like the old T700-R used to. 

Thanks for the info! I appreciate that. The first thermal bypass valve went bad because it was plugged from TCC shards. The second was a manufacturer fault.

 

At one point, just before the second thermostat change, the trans was reading a temp of 252°. Not pulling or hauling anything. Empty bed. I was frantic.

Edited June 5, 2023 by s10dragracer888