Transmission slips when hot

Hey Guy’s

I have a 2000 DTS that decides it want’s to work intermittently (perhaps there is some wiper motor confusion here). It slips and catches once the transmission warms up. Perhaps it wants to be a kind fisherman? It’s got 56k for mileage and I have replaced the fluid and filter. All the forward gears do this (1st is more just extremely sluggish (Uncle Fred?..are you in my tranny?). Any help offered would be very appreciated.

Thank You Gentlemen

Were the problems there before you changed the filter and fluid? If not then you need to recheck your work.

Did you get the filter installed correctly? Is the fluid level low or overfull?

It probably needs a rebuild.