e53 Transmission???

[undef.e53]

Hey all I've creeped these forums long enough and have found plenty of help within the posts but I've found an issue in my 01 3.0 that i just can't figure out. Maybe i didn't search well enough? Maybe i'm blind? who knows.

My X5 has been lunging from drive to park park to reverse etc. and around 55-60 mph the transmission light comes on (cute little orange gear with the exclamation point in middle). it does have other issues i'll be repairing when the parts come in such as Disa, Intake gasket, cam and o2 sensors but those offer legitimate codes so i can repair them but the transmission is out of my league and i'd like to know if anyone knows what could be the underlying issue. I purchased the vehicle not 3 week ago as a project but i get a feeling i might be over my head on this.

If anyone has any input on this a similar issue a solution anything would help. Thanks