Originally Posted by yellow_focus_tim
ok so recently out of no where my car starting to make a weird knocking noise. it only happens in neutral when my foot in not on the clutch. i was told it might be a bad throw out bearing but i just replaced the whole clutch kit. it stops as soon as i put my foot on the clutch. i have no clue what it is unless defective throwout bearing.
If I had a dollar for every time I had to explain this....
First off- did you replace the slave cylinder when you did the clutch? I always recommend that people replace the slave cylinder when doing a clutch. 1) it's a plastic part, 2) the release bearing will be glued to it possibly preventing rattling for some time.
What you're hearing is the release bearing rattling between the pressure plate forks and the slave cylinder. That's why it goes away when you press the clutch in. There's nothing wrong with the release bearing or the rest of the clutch or even the slave cylinder. Bad release bearings make a screaming sound when you press the clutch. The distance it's moving to make the rattle is hundredths of inches. I would rather have a release bearing that isn't making constant contact with the pressure plate than one that is. Of course, I'd really like to have one that doesn't rattle or contact the pressure plate at rest
Mine has been rattling for about 100k miles now.
If the slave cylinder is replaced at the same time as the rest of the clutch, then you end up throwing away the release bearing that comes with the clutch because one will be glued to the slave. Sometimes the glue lasts for years, and sometimes it separates in a few hours. Who knows why it lasts longer or not. I wish I did know, maybe you could either remove the release bearing from a new slave cylinder, then glue on the one that comes with the kit, or simply add some glue to it.
Some day I'll be able to get a few thousand off the price of a used Focus because of this sound