Transmission shifting issue

Alright this has gone on long enough without posing a question.

Back story: Got my transmission serviced and clutches replaced because they were slipping bad so those have been replaced and he warrantied the valve body as well. The guy before me towed and seems to have generally abused the vehicle.

The issue I'm having is a really hard shift from second into 3rd, then 5th into 6th. Like it's almost as if I'm getting rear ended it thuds so hard. Had him take a look at the valve body and he just replaced it even though it checked out because it sounded like that was the issue but no luck. It seems to be holding onto gears longer then it should then releasing a bunch of pressure and applying that into the shift.

On top of that I had my rear wheel bearings replaced by a different shop (by doubting the first) and had em service my differentials and they said they look great.

Now I can make the truck not shift hard by letting off the gas right before I know it's going to shift, i can also force it to clunk by a medium 3k-4k acceleration. I thought it was an ECU issue, or something to do with the shift points, possibly related to a warn out gas pedal? Or bad range sensor?

Anyone ever have an issue like this and fix it?

 

150k. I'll try the ECU reset, but i'm pretty sure they did that at the tranny shop already.

It's still there in S mode.

Thought about grabbing a tuner to see if that'd help, it'd probably be cheaper than a dealership inspection...

 

Might be a silly question, but do your reverse lights work?

I’ve fixed a similar issue with a different vehicle with an Aisin transmission, main problem was a physically broken range sensor and a misplaced reverse light fuse (owner pulled it to check, reinstalled it in the unused slot beside) You should have transmission fault codes for that though.

I’m also having trouble understanding why this “transmission shop” isn’t able to give a diagnosis based on reading live data with their scan tool on a test drive.

 

Did you have your torque converter replaced when they did the clutch disks?