do i have a bad throwout bearing?...

with the help of some good friends, i am able to formulate an intelligent question now.
when i am sitting at a stop light, with the car not in gear, i hear a faint, almost whining noise, it's not consistent or constant either. when i depress the clutch, the sound goes away.

also, every now and again, when i shift gears, there is a brief noise that sounds similar but it's not the same noise. this one happens just as i am putting the car into the gears.

i think i have it narrowed down to a bad throwout bearing, but before i go droppping the transmission, is there anything else i should be on the lookout for? could it be something more significant than just a throwout bearing?

thank you.

 

sounds like a throw out bearing to me,my truck does the same damb thing

 

how long can i let it go before it trashes something important?

this car is not a daily driver.

 

I'd drive it until it whines so bad you can not stand it, or you already have the tranny out. If its faint, it may not get louder for another 20,000 miles. I have never heard of one completely seizing. and as far as doing damage to anything. The only parts it comes into contact with are the clutch/pressure plate assembly, and the tranny input shaft. I suppose if it seized, it "could" damage the shaft. But you have to remember that the shaft is hardened and the bearing is not, so which do you think will take the damage?

 

not to shore,mines been making noise for a few months,

 

so when i do drop the transmission, can i replace the bearing and just do a visual inspection of the pressure plate and the shaft?
will that be sufficient?

 

May or may not be the throwout bearing. There is another possibility.

Possibly the clutch needs to be adjusted just a tad tighter. Just enough to bring the throwout bearing a little tighter to the pressure plate fingers, but not so much as to start disengaging the clutch.
Possibly the input shaft bearing is starting to go bad.

Usually if the throwout bearing is going bad it will make noise when you depress the clutch. If the input shaft bearing is going bad the noise would go away when you depress the clutch.(the input shaft doesn't turn with the clutch depressed)

 

depending on how old your clutch is ,wht not replace it since the trans is out???

 

ok, so if i adjust the clutch and the noise is still present, can i assume that the problem is the input shaft bearing?
...i'm trying to not take the transmission out if i absolutely don't have to.

 

i have seen throwout bearings seize up and wear a hole through the pressure plate.

 

I don't mean to change the subject, but I'm also having tranny trouble with my '50 Plymouth, basically I need to replace the clutch and bearings, pretty much an overhaul. Is it a pretty easy job for a home garage? Is it just taking apart and putting back together? Are the clutch adjustments pretty easy? Keep in mind I've never overhauled or replaced components of a manual tranny myself before...

 

with trans in nuetral and clutch pedal out,the throw out bearing IS spinning,when you depress the clutch pedal the throw out bearing will also stop spinning-id drive it till the noise gets louder,if the front bearing in trans was bad,noise would also be heard when driving,

 

With the trans in neutral and the clutch out the throwout bearing should not be spinning. When you push the clutch in the throwout bearing starts spinning as it engages the clutch fingers. I think you might have a bearing problem in the trans it's self.

 

The only thing you can do without pulling the trans is try the adjustment. Otherwise you will have to pull the tranny for the other solutions.
Changing the throwout bearing would probably be the fastest, cheapest, and easiest to try, unless you are comfortable and able to go into the trans yourself.
I would change the disc and pressure plate while its apart unless they are fairly new already. If it works out that the noise is still present then all you are really out is pulling the trans twice, since you should replace the clutch components while the trans is out for repair anyway.

 

I'm with flathead4D. The bearing does not touch and spin unless you engage the clutch or the clutch is adjusted too close. BTW, when if you replace the bearing look at the fork real good for extra wear or cracks. When I was younger and dumber I replaced the throwout in my '67 Corvette 4 times in one week. As soon as I put it back together and pushed in the clutch it ruined the bearing because my fork was worn so bad. I didn't know what it was supposed to loook like until I had someone smarter then me inspect things. Hard lessons are never forgotten.

 

Actually, it shouldn't touch the input shaft, but the front bearing retainer. If you make sure it's adjusted properly(does NOT contact clutch all the time), and have a good return spring (to pull it away from the pressure plate when your foot's off the pedal), it should be fine for quite some time i think. Also, don't "ride" the clutch pedal when you're not using it. It should get quite a bit noisier before it becomes a problem

 

From your description, it sounds like the trans input bearing is bad, not the throwout.

 

If it were the throwout bearing, the noise would begin when the clutch was depressed.

 

this is not correct information above. Listen to flathead4d. He is on the money.

 

I had a throwout bearing go out on me once. It was a brand new one too....one of those bearings with the plastic base that engages the clutch fork(this was on an S-10). The dang thing came seperated from the cheapo base and ate up the input shaft collar. Not sure of the term....but the sleeve that goes over the input shaft that the throwout bearing rides on....the throwout bearing ate that up.

It sounded kinda squealy and would go away. Finally it got real bad and I took it apart and found the throwout bearing mess.

It could possibly be the same thing you are dealing with. If so, you might be doing damage right now.

 

What transmissione' do you have? I have a T5 with a similar noise and I was told the aluminum bearing retainer is probably worn out and should be replaced with a steel one.

Thanks,
Kurt

 

it's a super T10

 

One of my initial thoughts too. But if the input bearing were going bad, he'd have noise in 1st, 2nd, & 3rd (if 4-spd) & 5th (if 5-spd) - there would be little/no noise in whichever gear is straight-through (1:1) - at least in the early stages of the bearing coming apart. This is because of the side loads put on the input bearing when it has to go through the cluster gear & countershaft - when going 1:1 straight through, there's little/no side load, just radial load.

I wouldn't rule it out completely, as it is a possibility (they can make noise sitting still in neutral, clutch out), but the T/O bearing is more likely.

When you have the trans out to do your T/O bearing, check the input shaft - most will be easy to pop the bearing retainer off & inspect the bearing - also, drain the gear oil & look for metal - a bad input bearing will show up as metal in the oil.

 

You're right, I don't remember if the original information was that specific. One additional thought, I had a situation where the pilot bushing was wiped out and caused the input bearing to go bad - that one was noisy in drive too.

Tredboy - replace or at least check your pilot bushing/bearing while it's apart. It's a little, cheap part that can cause big, expensive problems.

 

It's a bad pilot bearing, nothing else.

no clutch adjustment needed to solve that problem.

man up, pull the trans. replace the five dollar bearing. or go buy some ear plugs and wait until it ruins something major.

 

I've run into similar problems on a full size Chevy truck, and am having a groaning/screeching/whining problem with the throwout bearing now. Depending on my truck's mood, it will be louder sometimes, and quieter at others. Hell, it's even gone a day or two without making any noise at all. So, until I have to do it, I'm not going to screw with it at all.

I've also run into pilot bushings on this truck (sbc 350/5 speed) not so much going 'bad', but getting what I'd call 'dry.' What would happen is that when I would take off, especially under load, I'd hear a grumble for a second and then it'd go away. I put 30K miles on this truck with it doing that. When I tore it down, there was no real discernable damage or wear, and it was tight on the new bushing, so I put it back together and took off. About 15K miles later, the groan was back, but only on rare occasions.

Also, if you tear the trans out, and replace the pilot bushing, do yourself a favor and replace the clutch, pressure plate, throwout bearing, pilot bushing, AND have the flywheel ground. If you're already there, and unless you've replaced all of these parts recently, you'll save yourself some time and effort in the longrun.

 

Possibly O/T....but the SBC & BBC can benefit greatly from the installation of a roller pilot bearing....they offer them aftermarket now...but Chevy put them OE in the early '80s diesel (6.2), cost from a dealer or parts store, about $13.

 

Throwout bearing should NOT be contacting the clutch fingers until you depress the clutch. You have not have enough free play in the pedal. also make sure you have a good return spring on the clutch arm. The throw out bearing could be barely touching the fingers making the noise untill you push the clutch.

 

Finally someone with a clue.

 

Super t 10 are very well known for bad bearings.