JoesFC

Its been doing it since I got the car about a year (9k miles) ago, and the car has 72000 miles on it with an original clutch. The common throwout bearing whirring has always annoyed me, not to mention that it worries me as well, and makes me wonder if maybe I should get a new clutch and be done with it. Should I just wait until the clutch is toast or is it sensible to get it done now?

invinciblejets

I'd go ahead and replace it if you can....
get a clutch kit with pilot bearing and make sure you get a pilot bearing SEALl!

GrossPolluter

iTrader: (1)

And the special pilot bearing removal tool

s70simon

iTrader: (7)

Also make sure the kit has an alligning tool for the clutch and pressure plate. Some don't include them.

AGreen

iTrader: (11)

I thought my 88 convertible had a throw out bearing noise too. I replaced the clutch, throwout bearing, and pilot bearing. It ended up being the transmission input shaft bearing.

Just giving you a heads up. Hopefully it is the TOB.

sp0ngebob

iTrader: (1)

its most likely the TOB.

if its whurring, that means its still engaged on the fingers of the pressure plate (slightly) when not in use.

a little adjusting might be in order. Also if you can see the TOB, maybe a little grease on the q-tip ti libe the trans input shaft could help. you might be able to get at it through the throwout fork hole or the starter hole.

AGreen

iTrader: (11)

The input shaft bearing will also make noise under the same conditions. I'm most certainly not saying it is definitely that, just something to keep in mind.

Turbonut

iTrader: (1)

^If it were the trans, would the noise not stop when the clutch is depressed as the input shaft ceases to turn?
Make certain play in fork so that the TOB is off the cover and go from there.

AGreen

iTrader: (11)

Right, which is the same indication as the throwout bearing. The noise on the TOB is when it's unloaded, then goes away when the clutch pedal is pressed. I've seen it happen on 2 separate NA transmissions. After replacing the clutch, TOB, and pilot bearing, the issue persisted. I then swapped the transmission out and the noise went away. For about a year. I took the old transmission apart and rebuilt it with new bearings and blocking rings. That one ran great for another 12k miles (maybe more, since I sold that drive train back in 08).

Turbonut

iTrader: (1)

Sorry, but can't see how it can be the same as the T/O brg as this brg isn't turning when unloaded, but the trans input shaft/brg is, then when clutch engaged the T/O brg turns and the trans shaft stops. For any looking for the exception, yes, the trans shaft will continue to turn if the pilot brg is frozen.

AGreen

iTrader: (11)

Man, I really didn't want to make this into an argument.

Let's first discuss the indications of a throwout bearing going bad. Clutch engaged, car in neutral, foot off the clutch pedal. It will make noise. Disengage the clutch, it should stop making noise.
Now consider the input shaft bearing. Clutch engaged, car in neutral. The input shaft, countershaft, and the gears on the main shaft are all spinning, unloaded. Disengage the clutch, the input shaft will come to a stop. Not instantly, but it will.
So the indications are so very similar, it can be easily confused. I don't know how common it is for FCs, but it happened to mine twice. I have diagnosed and rebuilt several manual transmissions, and have not seen too many cases like the one I saw on the FC.

Turbonut

iTrader: (1)

Really not an argrument, just trying to get the OP the correct info, but with foot off the pedal, the T/O bearing should make no noise as the bearing shouldn't be turning as free-play keeps it off the fingers of the plate/cover. Now if there is no clearance, free-play, then the T/O bearing will constantly spin, not a good situation. Actually if the T/O bearing is making the noise when foot off pedal, no clearance, the sound shouldn't change when clutch disengaged as the bearing will continue to spin, but trans stops.

This is why the free-play should be investigated to make certain the T/O bearing isn't riding on the cover then one would know better where the noise is located.

invinciblejets

This was the case with my old trans.....Pedal out, noise...clutch in and it went away
Replaced trans and clutch kit and it quite as could be now but my old pressure plate fingers were gouged so I tend to think throw out bearing was part of the noise...but my trans was trash anyway.

P_Lav

Is it worth pulling the trans just to replace the TOB and pilot bearing/seal? Mines starting to annoy me, but my clutch has been replaced previously. Or do I wait till I need a clutch as well?

monty11ez

How long ago was it replaced? Also do you sit at traffic lights with your foot on the clutch?

P_Lav

Not sure, previous owner replaced it, the car only has 108k. Noise started last summer. And usually no, I put it in neutral. I also don't want to damage my input shaft or bearing either though.