zdriven28

Tranny has been shifting HARD out of 1st gear lately when I run it cold, it feels like it doesnt wanna shift but when it gets warmed up it runs fine. Well today I went out for a drive and it did it again, only this time I had been driving for about 20 min. and it didnt shift this time! It would rev to about 2grand at 10mph and the whole car felt like I had just slammed on the brake so I would throw it in neutral to prevent any possible damage. I ran it at 10mph all the way bak home cuz it didnt wanna shift. Anyone know what can possibly be causing this, I also hear and feel a little bang SOMETIMES under the car as well when driving at low speeds and when its struggling to shift. Any info would be greatly appreciated. O yea, its an auto 4l60e.

usd2sing

iTrader: (15)

subscribed

performabuilt

iTrader: (25)

Have you checked codes or looked at the data stream to see what gears are being comanded, When I say that I do not mean looking at for instance a tuner where you comand the shift and see if it happens, I mean looking at the data stream passivley not interactivly and see if the PCM is comanding the shifts on its own ?
However the braking affect under throttle I assume would concern me . I would do the scan first, Not sure about the banding sounds cant realy think of anything inside the trans that would cause that and the trans still work well warm.