2016 6 speed transmission downshifting.

[nluchau]

Update:  Sorry for the delay in writing this.  

Last month I had the valve body and TCM replaced.  It's still doing the same thing.  It's been a couple thousand miles now.  Is this just the nature of the beast?  

[adamj2121]

5 hours ago, nluchau said:

Update:  Sorry for the delay in writing this.  

Last month I had the valve body and TCM replaced.  It's still doing the same thing.  It's been a couple thousand miles now.  Is this just the nature of the beast?  

Similar issues with my truck, I had the same replacements, I can guarantee it is not normal. I have driven too many other 6 speed Silverados in the past year that have zero shifting issues and are seamless and smooth.

[nluchau]

On 4/10/2018 at 5:03 PM, adamj2121 said:

Similar issues with my truck, I had the same replacements, I can guarantee it is not normal. I have driven too many other 6 speed Silverados in the past year that have zero shifting issues and are seamless and smooth.

What is your next plan of attack? How many miles do you have? I'm at 20k now.  One thing I tried was this:  I put it in M5, accelerated until it hit 5th gear and coasted to a stop manually downshifting on the shifter and all I noticed was a blip of the RPM's, never once did I feel the harshness of the downshift like I normally feel.  What does this explain???

[vfm2010]

Need a third option... I manually downshift just to hear the exhaust cackle.

[Loco-diablo]

Very rarely (2 or 3 times in 15,000 miles) I've noticed the downshift, but it only happened when coming to an abrupt stop.

2017 - 5.3 - 6-speed - DC - 4X4

[FIREBLADE74]

Are you saying the tranny bangs into gear downshifting or rpms raising and slowing the truck. My 17 does the throttle blipping majority of the time and I’m not braking hard. I think it’s a nice feature saves the brake pads and less brake dust and with an exhaust it sounds like you mean business!

[adamj2121]

15 hours ago, nluchau said:

What is your next plan of attack? How many miles do you have? I'm at 20k now.  One thing I tried was this:  I put it in M5, accelerated until it hit 5th gear and coasted to a stop manually downshifting on the shifter and all I noticed was a blip of the RPM's, never once did I feel the harshness of the downshift like I normally feel.  What does this explain???

I have a major issue with the 1-2 shift, where it takes a second or two before the truck engages second, almost like if you were in a manual and miss second, ending up in neutral, then slammed into second once you realized. A field engineer is supposed to look at the truck for that issue, the flair shifts, and the clunky downshifts. This will be the second engineer to look at the truck, and I don't have much confidence they will be able to fix it. If I was not having the 1-2 shift issue I would go ahead and get a black bear tune. I have heard many great things about their tunes, and I do believe the downshift clunk is in the tuning, like you said manually shifting gears doesn't produce the clunk. 

[nluchau]

3 hours ago, adamj2121 said:

I have a major issue with the 1-2 shift, where it takes a second or two before the truck engages second, almost like if you were in a manual and miss second, ending up in neutral, then slammed into second once you realized. A field engineer is supposed to look at the truck for that issue, the flair shifts, and the clunky downshifts. This will be the second engineer to look at the truck, and I don't have much confidence they will be able to fix it. If I was not having the 1-2 shift issue I would go ahead and get a black bear tune. I have heard many great things about their tunes, and I do believe the downshift clunk is in the tuning, like you said manually shifting gears doesn't produce the clunk. 

Do you actually hear a clunk while the downshift occurs coasting?  I don't actually hear a clunk but I have a firm bump when mine happen.  My first 1-2 shift of the morning is somewhat harsh but that is the only time I notice anything odd with the 1-2 on mine.  Hope you get things figured out.  Keep me posted.  

[adamj2121]

1 hour ago, nluchau said:

Do you actually hear a clunk while the downshift occurs coasting?  I don't actually hear a clunk but I have a firm bump when mine happen.  My first 1-2 shift of the morning is somewhat harsh but that is the only time I notice anything odd with the 1-2 on mine.  Hope you get things figured out.  Keep me posted.  

Sometimes there is an audible clunk, I believe it is the leaf springs shifting from the abruptness of the shift. I will let you know if anything is discovered on my truck, it is currently in the shop and they are pulling data for the engineer.

[nluchau]

What do you guys think my next plan of attack should be with the dealer?  Would you have any reason to believe its the torque converter causing it?  I am not feeling a shudder while cruising at all, in fact I prefer driving it on interstate but stop and go its terrible.  The best way I can describe the feeling I get when it downshifts is obviously the RPM's rise a couple hundred and there is a brief hang up switching between gears and there is a sudden little jerk.  It happens like clock work on the 5-4, 4-3, 3-2, 2-1 shifting while coasting to a stop.  If I am heavy on the breaks I really dont notice it too terribly much.  

 

Ugh

[nluchau]

Has anyone had these downshift jerks fixed by the dealer?  If so what did they do?  Please advise. 

[Bob2C]

When I turn my a/c off it downshifts soo smooth. Then when I turn it back on it’s harsh again. So something is going on with the programming. Give it a try and turn the a/c off and see for yourselves.