Transmission hard shift

[Phantom 4D]

Took an 860 mile round trip this past weekend. After about 4 hours of seven hours driving, started hard shift. Stop and go traffic made it worse. Got to our destination hotel and rested about an hour before going to see family. Fifteen minute drive, traffic lights and hard shift. Weather was cold. Next morning, got on the road to visit family, standard cold weather noise from the rear end, grinding, popping. And guess what, hard shift. Return trip, much the same. Did I mention the rumble at 40-45?

A few days prior to this trip, I was in a parking lot, I backed up a few feet, put the truck in drive, it hesitated and shift was so hard, I thought someone hit me. I've about had it. About eight months ago, the dealer changed the trans fluid. Even though it had the correct fluid. So I'm going to take it back. If they don't make it right, I may have to look into something else. 

Yeah, I know I've posted on this before. And there is a class action lawsuit. But dammit, something has to be done. 

[SilveradoRST]

When was your truck build date?  8 speed right?  Did the dealer use the TSB to exchange the ATF?

[Okievision]

Starting to notice a strange "rumble" at city speeds, kind of like a vibration and it goes away when letting off the gas and coasting. Harder shifting too at 28K miles. 2019 GMC SLT. My Neighbors 2019 Denali spent 3 months at the dealer for a new transmission under warranty. He traded it the day it came out of the shop. Both 8 speeds. Just got the truck paid off, hate to have to trade. 

Build date 1/18/2019

Edited December 23, 2022 by Okievision

[SilveradoRST]

42 minutes ago, Okievision said:

Starting to notice a strange "rumble" at city speeds, kind of like a vibration and it goes away when letting off the gas and coasting. Harder shifting too at 28K miles. 2019 GMC SLT. My Neighbors 2019 Denali spent 3 months at the dealer for a new transmission under warranty. He traded it the day it came out of the shop. Both 8 speeds. Just got the truck paid off, hate to have to trade. 

Build date 1/18/2019

You should take TSB 19-NA-121 to the dealer and have them do the ATF exchange if you haven’t already.  

MC-10174268-9999.pdf

[Okievision]

Will go next week, much appreciated

[Okievision]

Dealer did the TSB ATF change, no charge. Paperwork showed this to be a $371 fluid change to the Mobil fluid. 

Not enough miles yet to really tell but knowing it's done is priceless, lol. 

 

[BlancoSilverado]

20 hours ago, Okievision said:

Dealer did the TSB ATF change, no charge. Paperwork showed this to be a $371 fluid change to the Mobil fluid. 

Not enough miles yet to really tell but knowing it's done is priceless, lol. 

 

Love to hear after a few hundred miles if if made a difference.

[Okievision]

700 miles since the TSB Mobil trans service. Still have the slight vibration feeling around 40-60mph but the jerky shifting has diminished greatly. 

[Minnvmax]

Not really related but I didn't want to start a new post. I just changed fluid and filter on my 2019 10-speed at 85k miles and it seems so much smoother.