What is a (transaxle) shaft bearing?

Yesterday I took in our '97 Saturn SL (5 spd. manual, 1.9L) because it was making a whistling/squeaking noise while in motion. The best description we've come up with is like a boiling tea kettle. As you go faster, the noise speeds up and becomes more continuous. It gets quieter in 4th gear and seems to be absent in 5th. Hadn't noticed it in reverse. The local Saturn dealer claims the shaft bearing was bad and its replacement was recommended. The tech had not heard a sound like that before.

The part (a kit of parts) is $400. Total parts, labor, tax estimate is $560. I couldn't find much on what a shaft bearing is or does. When I called for clarification, they said transaxle shaft bearing. I still couldn't find out much on what it does or get any idea of how much it should cost.

For $400 in parts, are they wanting to replace more than the bearings?
Is this a favorite repair of Saturn dealerships?

To make things even more confusing, driving home from the dealer, and today, the sound has completely disappeared. I'm taking it to another shop for a second opinion and now there's no sound for them to hear.

hi there...
this sounds a little similar to the problem i had last week.. when it was
very very cold here ( southern Ontario). my right front wheel started
squeaking after the car had been in motion for about 10 min..
using the brakes had no impact on the squeak.. no worse, no better..
i had 'Speedy' check out the brakes and they are fine.. I took the car to
a Saturn dealer, and they gave me a estimate, replacing the right
front axle.. or as the wreckers call it. a jack shaft.. Saturn was going to charge me $1200. for the job.. 2 1/2 hrs labor, and $725 for the 'jackshaft.. i got one from the wreckers for $50 !!! .. but now.
weather has warmed up,, the squeak is gone !!!
I went to the mechanic at Saturn and he said,, 'Oh..maybe it was from the coldness, and expansion and contraction . of the bearing.. '
Why didnt they say that before !!! sure glad i didnt have the work done..
good luck
Gary

i can't go into detail now but i think they are talking about the Input shaft bearing or the "quill" bearing.

UPDATE: The car continues to run without the noise. Shop #2 would not look at the car if there was no symptom. Even the manager was not quite clear what the Saturn dealer meant by "shaft bearing." I notified the dealer I would not be having the work done as long as there was no noise.

in the meantime, keep a eye on the fluid levels, incase a seal has a slow leak.

There is no such thing as input shaft bearing! one end runs into a a snap ring inside the trans. The other end runs to the nut between the rotor. If they are talking about the wheel bearing they should specify that! Which any tire shop can change for 1/3 of the price of dealer