Not trying to dissuade you from sending the camera in, but, is the film pressure plate absolutely clean? Does it only squeak with some films?
Does the film takeup squeak if you turn it with your fingers?
I'm guessing that the wind motor, on the left side of the camera (looking at the camera back, with the back open), needs lubricating.
Good luck with it
35mm : Leica 1A, M4, M9, R6.2, Nikon F/F2, Xpan II
6x6cm: Hasselblad 501CM, 203FE, SWC, Rolleiflex 2.8F, Wide
6x9cm: Fuji 690II/III, Bessa II, Super Ikonta 531/2
4x5in : Technika Master, Crown Graphic