HDJ80 making a whistling sound in 1st gear (1 Viewer)

[tonytone]

(Video link below).
Gonna check the transmission fluid levels, but I'm curious if anyone has run into this issue and what else you recommend I look for. Car is at about 130k kilometers. Whistling / whirring sound when i'm accelerating in first gear. After first the sound goes away.

 

[jellis]

Sounds exactly like a loose belt to me, and they also normally catch and stop squealing at speed--are you sure it's not coming from the engine bay and is in fact coming from the tranny?