RPMs when shifting

[05 1500HD]

I’ve got a ‘14 Silverado 1500 with 84,5xx miles on it. It doesn’t do this everyday or all the time but sometimes when it shifts from 1st to 2nd(I think) the rpm’s will go from 2,000 to 2,500 during the shift and then come back down once it shifts. It’s only on take offs and like I said it doesn’t do it every time or even everyday. 
 

Have any of you had this happen?

[newdude]

7 minutes ago, 05 1500HD said:

I’ve got a ‘14 Silverado 1500 with 84,5xx miles on it. It doesn’t do this everyday or all the time but sometimes when it shifts from 1st to 2nd(I think) the rpm’s will go from 2,000 to 2,500 during the shift and then come back down once it shifts. It’s only on take offs and like I said it doesn’t do it every time or even everyday. 
 

Have any of you had this happen?

 

 

1-2 or is it 2-3?  Does it most commonly do it say, you drive somewhere, get out and go to a store or say pump gas, and then when you get back in and drive away it does it?

 

2-3 shift flare is oddly enough a normal characteristic of the 6L50/80/90 transmissions.  No fix for that one.

 

If you are flaring the 1-2 shift, then I'd say you've got a possible issue in say the control valve body (delayed valve movement or engagement or shift solenoid) or something mechanical.  

Edited July 27, 2023 by newdude

[05 1500HD]

24 minutes ago, newdude said:

 

 

1-2 or is it 2-3?  Does it most commonly do it say, you drive somewhere, get out and go to a store or say pump gas, and then when you get back in and drive away it does it?

 

2-3 shift flare is oddly enough a normal characteristic of the 6L50/80/90 transmissions.  No fix for that one.

 

If you are flaring the 1-2 shift, then I'd say you've got a possible issue in say the control valve body (delayed valve movement or engagement or shift solenoid) or something mechanical.  

I was thinking about this driving back to work from lunch. It is actually 2nd-3rd.  So this is a pretty normal thing.  Seeing post on a group on Facebook has me worried or paranoid that the transmission or torque converter is going to go out. 

[05 1500HD]

It seems to do it when I leave for lunch or when I leave to go home from work. Normally that is when I notice it the most. 

[newdude]

10 minutes ago, 05 1500HD said:

I was thinking about this driving back to work from lunch. It is actually 2nd-3rd.  So this is a pretty normal thing.  Seeing post on a group on Facebook has me worried or paranoid that the transmission or torque converter is going to go out. 

 

9 minutes ago, 05 1500HD said:

It seems to do it when I leave for lunch or when I leave to go home from work. Normally that is when I notice it the most. 

 

 

I've had 4 trucks with a 6 speed, they all did the 2-3 flare.  If you had converter or pump failure, you'd notice shuddering during cruising and acceleration, if it was bad enough you'd possibly lose forward movement as its likely the converter is gone or its failure failed the fluid pump. 

 

6 speed converter failure is common on the 2014-2020 year range however.  If you haven't done so, I'd install either the lower temperature thermal bypass valve or do the pill flip or SureCool bypass kit to allow the transmission to operate at a lower temperature.  

 

Here's the GM bulletin on it:

 

22-NA-185: 2-3 Upshift Slip or Flare 

 

This condition is a NORMAL characteristic of the transmission, it will not cause durability concerns and no repair attempts should be made.

 

At this time this flare condition has been recognized in two different driving conditions:

During the first 2-3 upshift after the vehicle has been sitting, engine off for several hours.

This condition may be caused by air that is trapped in the 3-5-R clutch assembly.

When the first 2-3 upshift is made this trapped air is purged and the following 2-3 shifts will be normal with no flare.

When diagnosing this condition, a garage shift into reverse before drive will purge this air and prevent the 2-3 flare from occurring

This condition is a NORMAL characteristic of the transmission, it will not cause durability concerns and no repair attempts should be made.

Please communicate to the customer this will not impact the designed performance or reliability of the vehicle.

Please share this information with the customer, including a copy of this message.

 

When transmission ATF temperature is at or below 85 degrees F (30 degrees C).

This 2-3 upshift flare can occur until the ATF temperature warms.

If the 2-3 flare is determined to be ATF temperature sensitive use a Tech 2 or GDS2 to make note of the throttle position when the flare occurs

Drive the vehicle to get ATF temperature to at least 104 degrees F (40 degrees C) and then make several 2-3 shifts at the throttle position determined to be the most sensitive to the 2-3 flare.

This will allow the transmission adapts to tailor the shifts and may help to eliminate the cold 2-3 flare.

This condition is a NORMAL characteristic of the transmission, it will not cause durability concerns and no repair attempts should be made.

Please share this information with the customer, including a copy of this message.

Edited July 27, 2023 by newdude

[Grumpy Bear]

2 hours ago, newdude said:

When diagnosing this condition, a garage shift into reverse before drive will purge this air and prevent the 2-3 flare from occurring

 

That thar is GOLD! Thanks DUDE!!