Clutch noise in neutral

[msoft]

My 635 from 79 with a 5-speed dogleg was sitting for 20+ years before I bought it and now when I start driving it again, I notice the following:

-First engine start of the day, everything sounds normal, i.e. no noises.
-Once I press and release the clutch once, I hear a rattling noise from the clutch/gearbox
-When the clutch is pressed, the noise goes away.
-When released, noise is back.
-It is a bit hard to put in first gear and maybe second, but otherwise when driving I hear no noise.

Could this be due to that the the grease on the splines has hardened so that the clutch disk doesn't go all the way back to engage fully with the flywheel but when sitting over night, the pressure plate slowly moves it into position?

[plip1953]

My 635 from 79 with a 5-speed dogleg was sitting for 20+ years before I bought it and now when I start driving it again, I notice the following:

-First engine start of the day, everything sounds normal, i.e. no noises.
-Once I press and release the clutch once, I hear a rattling noise from the clutch/gearbox
-When the clutch is pressed, the noise goes away.
-When released, noise is back.
-It is a bit hard to put in first gear and maybe second, but otherwise when driving I hear no noise.

Could this be due to that the the grease on the splines has hardened so that the clutch disk doesn't go all the way back to engage fully with the flywheel but when sitting over night, the pressure plate slowly moves it into position?

This kind of noise would be typical if you had a multi plate clutch, but in that instance the rattling noise occurs when the clutch is depressed. All I can think of in your case is that you have a failing clutch release bearing.

[bpoliakoff]

^^^

[GRNSHRK]

Plus 2, although I thought it was called the throw-out bearing

Bottom line, this is one of those "while you're in there" repairs that once the tranny is out, you are going to wind up replacing all of the clutch components

And don't forget the needle bearing in the end of the crankshaft

[Ralph in Socal]

Noise goes away when the clutch is depressed and returns when the pedal is released. The TOB is not in contact and therefore not moving/turning when the pedal is released so not likely the TOB.

Also not likely a stuck grease issue as the forces involved, along with the minimal length of travel, can overcome that scenario. If the input shaft and clutch disc hub mating surfaces were rusted together then you could possible have the slow movement

The clutch fork basically "floats" on the tube extension of the transmission. It moves to engage the TOB with the pressure plate when the pedal is depressed. The clutch fork pivots on a plastic pin that is opposite of the slave cylinder. The plastic pin is a known wear item and I suspect is your likely culprit. The tip of the plastic pivot wears down so that the fork will not move forward as much as necessary and makes shifting a little bit harder. The fork, though it is floating, has a spring retainer to maintain its proper location. A worn pivot can cause the fork the vibrate in place as the spring is not able to keep it tight against the pivot. Good luck

Ralph

[msoft]

Thank you for your input! Forgot to mention that the clutch slave cylinder is new.

I think I will drive the car for a while to see if the noise goes away but soon remove the transmission anyway and go through the clutch components. Is it complicated to replace the crankshaft needle bearing?

[Ralph in Socal]

Crankshaft needle bearing is more typically called the Pilot Bearing. Old style with felt, dust washer and separate needle type bearing has been superceded by a one piece sealed bearing. Much easier to install

I remember someone having difficulty as there's usually a removable spacer between the crank and the bearing shell that has to be removed to fit the new style sealed bearing

Replace the rear crank seal while it's accessible

Ralph

[Pod]

Deffo the release bearing.

[msoft]

Status update: The gearbox noise in my case was due to a bad bearing inside the gearbox. It is now completely renovated (all bearings replaced) and completely quiet.