2-3 "Flare" When shifting

[McBuck]

My 04' Z71 has 170K and runs great. But my 2-3 shift has an RPM "flare" of about 300-500 rpms tha almost feels like a slip. If I am driving fairly "by the book"
I barely notice, but if I an om the gas then the flare is more noticeable. If I am in 3rd already and I get on it and it down shifts, the rpms really jack up...3000+ revs. The truck NEVER loses and pull through any of these events. My son owned this truck before and there were NO upgrades of any type; however the truck was put on its side ( drive side) in an accident, and he said after the roll is when this started. It was a pretty soft roll and only caused a bunch of wrinkles.

 

[BlackedOutHoe]

I can't help, but mine has done this for years so I'll be watching to see what others say. I can also add for mine, that it becomes more pronounced as the trans fluid warms up.

 

[McBuck]

I can't help, but mine has done this for years so I'll be watching to see what others say. I can also add for mine, that it becomes more pronounced as the trans fluid warms up.

I added some Marvel Mystery oil to the trans fluid, and it seemed to help some.

 

[PNWYukon]

A defective solenoid can cause the transmission to slip.

What’s a transmission solenoid?

A transmission solenoid is an electro-magnetic component used to control the flow of transmission fluid in the transmission.

Every time a gear is shifted, the car’s computer – Engine Control Module (ECM) or Transmission Control Module (TCM) – actuates a transmission solenoid, which pushes transmission fluid into the valve body to engage the right gear.

Through this process the transmission solenoid regulates how much fluid is passed through the transmission. If the solenoid malfunctions, not enough fluid is pumped into the transmission, which will result in the transmission overheating and slipping.