2.5L ('98-'01) whirring noise

[youngbuckwithapickuptruck]

yr2000 4cyl mt 340kmi ranger recently started making a "whurrrrrrrrr" whining noise when driving 1st and 2nd gear and also while in third gear when loaded with 500lb in the bed.
noise stops and then starts again between shifts.
"WHRRRrrr *shift* WHRRRrrrrrrrr *shift* WHRRRrrrrrrrrrrrrrrrrrrrrrrrrr...."
the noise started about a week ago. perhaps higher speeds drown out the noise. any idea whats going on?

additional notes:
-iirc the noise also came for about 2weeks and then stopped a few months back.
-i do a lot of irregular driving, some
weeks ill drive maybe one short 5-30mile
trip, other weeks i may lay down 1000miles.
-also i have p0442 fuel evaporate "gas cap" code, could it be related?
-my belt started squealing in the past 6weeks or so. i changed serpentine belt in 2018. the belt was barely squeaking during todays 200mi drive.
-also for past 2years ive been taking a few 500mile trips with a 1500lb trailer. and recently i did the drive with a 200lb buddy with about 800lb in the bed (no trailer). we had to take turns driving through hilly highways and whenever i would wake up, i would look at the computer and he would be at like 90-100% load. fkkkk i hate when other people drive my truck

....iirc ive heard a transmission with no oil before and its a similar noise. when my truck was last making noise, i checked trans fluid and it look clean and purple... i think.
iirc i changed trans fluid about 2-3years ago.

google search query for "whurrring noise" didnt bring up much.

 

[scotts90ranger]

does it sound like it's coming from the transmission area? If so either the throwout bearing is going out (loading them like having the clutch disengaged sometimes quiets them down) or the pocket bearing bearing between the input and output shaft in the transmission or maybe the front bearing on the counter shaft... unless you got a mouse nest in the bellhousing or something dumb...

 

[youngbuckwithapickuptruck]

i cant really tell where the vehicle noises are coming from inside the single cab, how do i differentiate between engine noise and transmission noise?