"turbo" whine?

[BerniniCaCO3]

Hey!

Someone else on a thread, months ago and long lost to me and to the search engine at least with my key word choices, described that their transmission made a sound like a turbo spooling up.
I used to be into model aircraft, not in a big way, and had a tiny 40,000rpm electric turbine for thrust. It sounds like that. Or remotely like a teapot whistle.

So anyway, rebuilt my transmission, end to end, and minus a couple blips --sticking governor and too-short OD servo piston-- it works great. Starting this afternoon, after 3 days of driving, it starts making this noise now. Intermittent.
In tune with engine rpm/throttle and more noticeable at low speeds (maybe just less road noise). Constant at first when I got into the car to leave work, and seeming to go away once warmed up; though maybe not for good, as I heard it once more on the way back home.

Hoping either the one guy who had this symptom, or others, will chime in with what it is, and, if it's a problem! Maybe it's a whine that just now passes into the audible range; and it's normal, not a worrying symptom, and I can just turn on the music to mask it?

[chitownvic]

AOD's do have a lil whine to em both of my cars did upon acceleration IDk if yours is worse than normal tho.. Cant hear mine anymore cause of my exhaust LOL

[miamibob]

My '95 has more of a "whine" than my '87!

[gadget73]

first and second whines in the entire AOD family. It has to do with the straight cut gears in the planetary set. It makes it stronger, but noisier. Nothing you can do about it, and nothing you should worry about. If it makes a noise when stopped in drive that sounds like the power steering pump, its something to do with a check ball thats in the TV pressure circuit buzzing around in it's bore. Usually happens when the pressure is towards the high side, and/or the bore it sits in has a smidge of excess play. Also not really a problem.

[BerniniCaCO3]

Funny, my old transmission didn't make this noise.
But the AODE planetary set that's in there was inspected, and has no chips, so what the hell. Probably OK.
Definitely not a power steering whine; I'm now well familiarized with that particular sound.
Doesn't make a sound when at a stop, so must be the planetaries.

Thanks for the assurance!
This being a new transmission and a risky project, I'm hyper sensitive to any little issue.

I remember asking the omniscient old dude in the shop about how an idler pulley on my sister's car could have gone from silent for the first week we owned and fixed it up, to suddenly noisy literally overnight. Got in the car, and there was a whine, that hadn't been there at all the very day before.
His theory, and it's sensible, is that it may have been whining all along but outside of the human hearing range, until it fell into a frequency that I could finally hear. Just like tube tv whine that, I understand, I'll lose the ability to hear some day (probably long after there are no tube tvs anyway) He gave the ..corollary? Is this the right use of the word? Gave the related example of some high-rpm device that would pass into and out of hearing range as it went up in rpms. You could hear it at every harmonic, and then it would go silent, and then become audible again at an octave higher pitch, then silent, then audible again, as it went faster and faster. I cannot recall what it was; not car related though.
So perhaps that's what's going on here.

[BerniniCaCO3]

What do bad thrust bearings in a transmission sound like, just for curiosity?
Though these, too, were all examined and approved of; so it seems unlikely.

[BerniniCaCO3]

unless thrust bearings rapidly go from noisy, to falling apart; so the only symptom of a thrust bearing is when it wraps itself around a gear set and you hear a horrible grinding sound and the gear locks up?

I think I remember my transmission guy telling me about a 4r70w that a lady was backing up, when all of a sudden it came to a stop; and it was a thrust bearing that had come apart. He said there was no negligence on her part; probably no warning that anything was going to go wrong.
So maybe thrust bearings don't make a whining or any other noise before failing, anyway.

[gadget73]

thats probably what happened with my S10. I backed out of the driveway and it made a chunking sort of feeling. Pulled it back forward and it did the same. Slowly drove down the road, it went Ping! and worked more or less normally. Dropped the pan and found a handful of metal and some little bits of rollers and shit. I drove it until it would not go any more, about 10k miles. When the trans was taken apart, it was full of metal shavings, the planetary gears needed dentures, and the only thing that could be salvaged was the case itself.