Clutch release bearing knackered?

[Ivor Hawkins]

The clutch release bearing has made a whizzing noise for the past couple of thousand miles, so I pulled the engine and box.

Firstly, I found out why I have to double de clutch up and down between third and top…I hadn’t noticed before, it has a crash box, so I’ll have to search out a synchro box.

Secondly, and more mystifying is that the bearing has no play in it and is absolutely quiet when I spin it…could it still be worn out?

The learned council of experienced A7 friends will be grateful received and faithfully applied!
   

[Chris KC]

I wouldn't worry too much about a hiss from the release bearing when you depress the clutch pedal. But having got as far as you have, Jamie sells nice new ones.

As for the crash box, the ratios are slightly lower than in the synchro box - which you might view as a curse or a blessing depending on how you use the car; but it is also massively robust by comparison. Worth thinking about before you toss it aside.

[David Stepney]

I agree with Chris. I am so grateful that my own car has a crash box!

[Robert Foreman]

Ivor, 
    with the thrust race if you dismantle it, then check the condition of the balls and tracks. 
If the balls are pitted replace them and if the tracks are pitted you will need a new race. 
  Re the whizzing remove the clutch centre plate and check to see if the rivets holding the spline on are tight. My RP had the same issue and was traced to the spline rivets being loose.

[Reckless Rat]

+1 from me too as regards the 4 speed crash box. Very simple, but robust.

[Ivor Hawkins]

Thanks chaps you are all gentlemen and scholars!

I shall pull the bearing to bits and have a look, but is quite a loud whizzing sound so will check the clutch as well.

As to the box, I won’t change it, but should I have to double de clutch up from third to top? Never had to with crash boxes in the past, usually just a steady slow change was fine…

[David Stepney]

Ivor, I think the answer is probably ‘yes’. Third and top are actually engaged via a dog clutch, rather than by sliding pinions.

[Reckless Rat]

I always double the changes, both up & down. Slowly is the way. especially when the engine/gearbox is cold.

Something else to check while you've got it to bits - the oiler. Make sure that it isn't blocked, within the casting that holds the bearing. Mine was. Sorting the lubrication solved my whizzy release.

[Ivor Hawkins]

David and Bruce, I’m sold! I’ll put the crash box back in (despite the fact it should be a synchro) and double de clutch up and down it’s no real problem apart from losing speed between third and top going up hills.

I shall report back with progress!

[David Stepney]

Its actually a very cleverly designed box. Somewhere in these annals there is a cutaway view of its internals. Briefly, though, third gear cluster moves on both the layshaft and the mainshaft to engage third and fourth.