Silverado 2-3 Harsh Shift

alkaspeltzar · April 25, 2018

2014, 5.3L, 86000 miles, Silverado 4x4 with 3.42 gear

As title says it has a harsh shift from 2-3 in the morning when cold(30-60 degree in MN). Bulletin says it goes away with oil temp which is true. Notice once above 100F it is good. But mine is not so much a shift flair but a harsh shift, like dropping the clutch in manual

Anyone else experience this? Is this bulletin correct or do I have another problem before my 5 year/100000 runs out? Thank you

PIP5429: 2-3 Upshift Slip or Flare

Some customers may comment on a 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.
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 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.

curver900 · April 26, 2018

Just started or getting worse? does it go away per the "normal" operation bulletin? when did you have your fluid changed?

nluchau · April 27, 2018

My 2016 shifts a little hard from 1-2, 2-3 in the morning until it gets up to operating temp and then the upshifts feel fairly smooth.

adamj2121 · April 27, 2018

The characteristics of my 1-2 shift sound similar to what you are describing for your 2-3 shift. Mine happens most frequently under heavy acceleration, but does not seem to be affected by ambient temperature, trans temperature, inclines, declines, etc. It also does not go away after the first shift, the dealer actually printed out a bulletin similar to the one you posted here and said it was normal. I have had it back multiple times for the shifting issue, there is no way it is normal and it is completely unacceptable. My truck has been at the dealer for almost the entirety of 2018 so far to address the transmission issue. I have been told a ridiculous number of things that are not the case:

1. one tech explained the transmission shifts from 1 to 5 due to the speed it is running (blatant lie, and I called him on his BS)

2. one tech blamed it on my driving style (the other 15 loaners I have had over the past year don't do it and I drive them way harder than my truck, so again not the issue)

3. the dealership decided it was the adaptive parameters (the params were reset and the shifting remains unchanged)

4. a field engineer looked at the truck and determined all numbers were within spec and did nothing to the truck.

I didn't get to talk to the engineer, but I would've really liked to get his insight on why he thinks it is happening. So now it is back at the dealership, waiting for another engineer to look at it.

If your shifting concerns go away once the trans is up to operating temperature, then I believe you are okay. These trucks, well any vehicle really, will exhibit weird shifting behavior until the trans fluid is warmed up. And if it is truly something that is not right about the shifting characteristics but it doesn't throw a code and is hard to replicate consistently then you are going to have a long process ahead of you trying to get the truck fixed.

alkaspeltzar · July 31, 2018

Well I am going back in to see what the Tranny experts have to say. Yes it goes away as it warms up. Possibly the truck and clutch packs are getting worn after 90k of hard miles, stop and go and such. So maybe when it warms up, then things clam down.

I know that the fluid in these make a big difference esp. with temperature. I also know the transmission increase line pressure during startup to help warm themselves and engine and possibly I am feeling that more as the truck ages.

Regardless, I don't like it and will be following up with what I find.

Silverado-Hareek · July 31, 2018

My truck has done this ever since they did a software update sometime within the first year of ownership. In my opinion, it's a tune issue. I've had the fluid changed recently with BG synthetic fluid and that made no difference. It's the tune in my opinion, coupled with the AFM and all the "figuring" the truck is trying to do to control all of these different parameters. I'm just waiting for the warranty to be up and then I'm turning off AFM and I'll see about playing around with the transmission shift points at that time.

Edited July 31, 2018 by Silverado-Hareek