weird noise in 4th at highway speed before lockup

[stonny9]

i have a 93 3.4 auto w 144000 miles. when on the highway and in fourth before lockup like when u give it gas to accelerate but it is only enough to unlock the tranny and not downshift to third it makes a weird noise that kinda sounds like grinding/fluid pumping. the tranny stills shifts like it has always donw and yes it has the right amount of fluid in it. what could this noise be and does it sound like it could be something that make soon break

[Turbo V6 Camaro]

kinda sounds like it might be to TC going out, but im not a expert in autos, maybe someone else can give you more info