• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

throw out bearing noise?

19_again

Jedi Warrior
Offline
Engine tranny all in, starts up and purrs but still no clutch. Bleed the lines and plenty of pressure-feels great. start the car and when even the slightest bit of pressure is applied to the clutch pedal there is a whining sort of sound that increases in volume as the clutch is depressed further and also seems to create a drag on the engine the further in the clutch pedal goes. I haven't done it, but it feels as if I could stall the engine if I were to depress it all the way and hold it there. tell me anything except that I need to pull the engine again.
 
Possibly the throwout bearing but that normally whirrs when the car is in neutral and the clutch out and goes silent when the clutch is depressed.

More likely I think to be the pilot / spigot bush in the crankshaft being dry or an incorrect fit.
As you depress the clutch the thrust is taken by the pilot bush and that is what is causing the noise. The fact it increases with load is a fairly good sign as well.

Now the news you really don't want to hear and I'm sorry but there is no other way to put it:
A fix for either is an engine / gearbox apart job.

Before you do anything though get more opinions and advice. I might not be right and it may be something you don't need to haul the engine out to resolve.

Good luck in any case ,
Cheers , Pete.
 
Pete is probably correct. The pilot bush (grabbing) may not let the trans input shaft stop turning. Or you could have something like the clutch disc in backwards?? Just a guess on that one but the metal center of the disc would be in direct contact with the flywheel. Get the wrenches ready and pull it back out! Bob
 
Yup. No choice. Gotta R&R the unit.

I go with Bob's "plate theory". The T/O bearing is graphite on your car, not likely to make noise whether engaged or not. I've seen 'em worn to the point the face of the plate was eating into the steel housing and there was no noise. Just a diminished engagement point at the pedal. If the disk is in backwards tho, it would act in the way you describe.
 
I didn't touch the clutch other than to rebuild the slave cylinder, left everything intact on the engine as the clutch was in fine shape prior to new tranny. Just spoke to John Esposito and he suggested the old hose may be blocking the back pressure from the slave, not allowing the clutch to disengage. We'll try throwing her in gear and seeing if I can push her. Then I'll pray to the Hawaiian clutch gods, then I'll up my BCF membership to double secret gold platinum and if that don't work, I'll pull that lovely unit once again.
 
19_again said:
I didn't touch the clutch other than to rebuild the slave cylinder, left everything intact on the engine as the clutch was in fine shape prior to new tranny. Just spoke to John Esposito and he suggested the old hose may be blocking the back pressure from the slave, not allowing the clutch to disengage. We'll try throwing her in gear and seeing if I can push her. Then I'll pray to the Hawaiian clutch gods, then I'll up my BCF membership to double secret gold platinum and if that don't work, I'll pull that lovely unit once again.

Joe could be right. I had a front brake hose go bad internally and after applying the brakes, the loose rubber in side the hose acted like a valve and wouldn't let it release. This could work both ways if conditions were right. If it's an old hose, I'd replace it anyway. Who knows. Just another thought.
 
Ah. I thought it had been given a new clutch. The hose (or other flex lines in the brake system) can deteriorate and do exactly what Paul says. Replace it if it's old, yes. But it wouldn't make noises. After it has sat for a few hours, have someone depress the clutch as you watch. Measure the distance from "rest" to fully depressed, release and be sure it returns all the way (if not, the flex hose is suspect). Pump and see if the stroke gets any longer on second and/or third stroke (if so, there may still be air in the line or the hose is "valving").

Some other thoughts:

I've seen throw-out "fork" pivot bolts so worn they resembled crankshafts, clutch would not completely disengage with that and there were some rattly noises associated.

The steel spring clips holding the T/O bearing in place not turned to clip correctly can "jangle".

A loose or broken "finger" spring on the P/Plate could be making the noises AND causing the resistance to pushing the clutch.
 
erm ... yeah... check that out... you don't wanna be like me and my clutch.... Steve_S saw the reminants of my throw out bearing. Needless to say, I ~never~ hold the clutch in for more than a few seconds anymore.
 
well the answer is I put the fork in back wards, not only that but I didn't know about the retainer as there weren't any in position when I removed the old bearing.We found one of them balanced on the edge of the starter hole and that opened our eyes. Fortunately the damage is minimal, except to my pride. Thanks to you all for the tips.
Mike
 

Attachments

  • 16876.jpg
    16876.jpg
    57.3 KB · Views: 218
  • 16877.jpg
    16877.jpg
    67.7 KB · Views: 215
  • 16878.jpg
    16878.jpg
    65.2 KB · Views: 231
yikes.
 
That's not going to throw anything out except your new parts. Lucky that is was not worse.
 
Yikes indeed!! Can you believe that move?? It was pretty clear that it had to be something down in the bell housing, but we shut her down so quick that we had to guess and use all your advice, thanks again.
Mike
PS. I'll be wrapping up the installation this week and will file one final report telling you'all how great it runs.
 
Mike! How's it goin'?!?!
 
Funny you should ask!! I just pulled her into the garage, MY OWN!!!! Everything is great, Quantum's new rebuilt tranny is nice and tight- very happy with it. The new throw out bearing gives me a clutch action that is a delight. My throttle cable is kinda sticky, it's brand new. A little grease on it and it'll be fine. The mystery of the choke cable continues as I get a real funky feel at the dash end, but it's all pretty sloppy back there. I'll get to it next week.
Thanks to everyone for the input, it's a great feeling to have a backup team like this forum provides.
 
Back
Top