yea now it wont make the same sound, but I think I know what you mean about the throwout bearing, when I push in the clutch it gets quieter and sometimes no noise but at idle its like a low hum.. is that right?

Yea ive rebuild transmission if you can imagine but I never had to diagnose the issues

 

Not exactly... thats the opposite of a bad throwout bearing.

The throwout bearing sits on the fork that the slave cylinder pushes in to the pressure plate to release the clutch. The throwout bearing sits idly until you push the clutch pedal down... where it is thrust into the pressure plate. It spins with the pressure plate on one side and sits still on the fork on the other side... hence the bearing. So basically, it would make no noise unless you had the clutch pedal depressed.

The pilot bearing sits in the end of the engine's crankshaft, and the transmission's input shaft slides into it. When the engine is turning at a different rate than the transmission's input shaft, it spins that bearing. When the engine and transmission are spinning at the same rate, the pilot bearing does nothing but hold the shafts together. But now that I think about it, the two shafts only spin different rates when the clutch is dissengaged (pedal depressed).

So now that I've thought about it and typed that all out, I think I've talked myself out of it being the pilot bearing after all. It doesn't really fit your description anymore.

 

Well I've been trying to think about what else it can be, but I'm at a loss right now. I was really set on those bearings until I gave it a second thought! Could you be a little more specific about the noise? More information might help.

Also, when was the last time you changed the fluid in that transmission and what did you put in? (manual transmission fluid should be changed every 30,000 miles or so).

 

Hm.. now that you say that it does make sense that it would be something else..


Its like when i press the gas (sometimes) it makes this whining noise that sounds like when your breaks squeel or something... when im in gear its happened also but after i let it sit and turned it back on tonite it didnt make any noise but i didnt drive it. If im idleing i can hear it sometimes but not all the time. When i was driving i heard it when i was needing to change gears from 2-3 3-4 but nothing in 5... (low rpm)

I just swapped the oil, 3qts of 75-90 and 1 qt of Lucas oil stabalizer (.7qt)

and just changed the oil, pcv valve, breather hose/filter, fuel pump, thermostat.. i noticed it right before i changed my fuel pump but i swapped that and it didnt make that noise for about 2 weeks. But its back... hm

If I can record it ill post that, that is if it comes back

 

I have a couple things for you to try to rule things out...

1) Depress the clutch, crank the engine, and listen for the noise, but don't let up off the clutch... keep it depressed. If you don't hear the noise, rev the engine while still keeping your foot on the clutch. If you hear the noise, its not anything in the transmission (although it could still be the pilot or throwout bearing... just not likely)

2) If you don't hear it, release the clutch in neutral and rev the engine. If you hear the noise after that, its likely a bad bearing somewhere in the transmission... probably an input or intermediate shaft bearing gone bad.

3) If you still haven't heard the noise, take it for a drive and see if it comes back.

 

Well the hard thing is that i cant rev the engine to have the noise get louder, its a quiet but noticable when driving noise (becuase it quiet in the cab) but i reved it.. i heard it slightly at idle with the clutch released, i dont know if i heard it when the clutch was pressed, i may have but it didnt sound like it.

I drove it around for a little bit and noticed it did come back when I was in 2/3 with a high rev, but at low rev there was no sound.. and its not really bad..

I dunno... sorry I really apriciate your help!

But its not 24/7 that I hear it, if that helps like I said it went away for a while than came back.

 

Lol, this noise just won't fit completely into any of the ideas I have!

Whining/screeching noises are typically related to bearings, but I just can't think of which bearing it would be. It sounds like a very sporadic problem... which doesn't help at all!

Maybe you should eliminate a vacuum leak causing the noise by standing by the engine and revving it up with the throttle lever on the throttle body.

 

I was able to do that on two occasions so far, once before the fuel pump a few weeks ago and than today I did that again, it sounded like it was coming from behing the engine, I dont see too many vacuums lol just the EGR stuff and the pcv is there anything on the top of the crankshaft? or behind the exhaust manifold? I would assume that a major issue would be really loud at high rpm (eg. metal on metal) but i was thinking if you pressureized one of those kazoo's it might make this sound lol but its more metalic i dunno

 

Yeah... I was just trying to rule something out!

I still think it is a bearing somewhere.

Is your truck 4 wheel drive or 2 wheel drive?

 

just 2... I wish it was 4