Learn me throwout bearings and strange noises that accompany them

Yes, I'm dumb. Even though I've seen the insides of an M5OD clutch 3 times, I would still like some explanation of the throwout bearing and when it moves. Chasing a driveline related noise in my ranger, brakes, u joints, and wheel bearings have been checked already.

What I know - throwout and slave cylinder are 1 unit, bolted to the inside of the tranny around the input shaft. Bearing rests on pressure plate fingers. I have strange squeaking noises at different speeds, neutral or in gear, seems to be inconsistent and thus hard to track down.

When does the throwout spin? I'd assume always? When do they usually make noises? Is this my rear end, since the rest of the drive train components check out?

The throwout bearing probably does spin constantly in your application, but it only works hard when you step on the clutch. If your noise changes when you take up the slack in the pedal, it probably is your noise, but it may not be critical. A little chirp with foot off, that fades when you put pressure on probably just means its dancing around, and short of lube somewhere. If it gets more intense with pressure, the bearing is probably dying. If its ok until you get the pedal down and put the trans in gear, truck not moving, the pilot bearing might be bad, but it can't make noise when your foot is off the pedal. No change with foot, makes noise all the time, its something attached to the motor. Makes noises only when you start moving, and changes with speed, wheel bearings, diff bearings, driveshaft support bearing, stiff ujoint. If the noise fades away when you depress the pedal all the way to the floor, vehicle not moving, you likely have an internal transmission issue.

My ceramic TOB on my '91 kinda has a chattering noise to it. Seems to be normal. LoL

Streetwiseguy, I need to bookmark that. One of the best diagnostic descriptions I have seen for strange driveline noises.

In reply to Streetwiseguy:

That is a damn good list! Unfortunately, not sure it narrows it down enough for me. Not engine related, must be moving.

Makes noise when slowing down, in gear or in neutral, clutch in or clutch out. not at all speeds, and not all the time. Changes with speed, ie if you're going slower its less frequent but still there. Definitely sounds like a bearing or something rubbing on the driveshaft, but i've checked driveshaft for stuff rubbing already.

already did U joints, since they were old and i hoped that might be the problem. Based on my tests, that could be transmission bearing? (though doesn't do when parked) or rear differential. no 4x4 so only 1 piece driveshaft. sound rightish? any way to narrow it down further?

In reply to Brokeback:

Maybe just wait til something falls off...

A bad bearing is likely to be pretty consistent, wherever it might be.

Doe the noise change if you ride the brake a bit?

In reply to Streetwiseguy:

Haha! Thats my current plan, since I've tested most of the things I can think of. Hopefully it isn't anything too catastrophic

Slowing down would by letting off on the gas would change the driveshaft a little bit right? i'm guessing it might be the differential pinion bearing but thats just a guess.

Brakes don't make a difference, they were the first thing i checked but they check out fine.

Pinion bearing doesn't care about load. If it changes noise based on load/coast, its probably gear related.

In reply to Streetwiseguy: That sucks, since the transmission in there has less than 80k on it :-( it replaced the original cause the PO learned to drive manual on it and burnt up the 1-2 synchro. Maybe sitting in a junkyard for a few years didn't do good things to this transmission lol.

Could be a rear end gear too.....I killed a few of those in s-10's. Granted they just grenaded one day instead of making any warning noises.

In reply to yamaha:

Not sure which one I would prefer haha. I'm currently trying to decide if i should just let it keep getting worse/more obvious, or try to preemptively fix something.

If its a gear, either trans or diff, they are way too expensive to repair, so just let it deteriorate until you can't hear the radio anymore. Then head to the pic'n'pull for whichever part you need.