which bearing spins

[OLDGIT ST]

hi guys

im replacing my gearbox BUT now more out of curiosity than anything, what when the clutch is fully engaged (ie pedal fully up) spins constantly in the gearbox all gears and neutral ?
and why placing pressure on the clutch pedal to the point of resistance is felt would either stop spinning or start to tighten up ?

The needle roller bearing on the end of the crankshaft - does that ever produce problems ?

cheers
og

 

[Happystamps]

hi guys

im replacing my gearbox BUT now more out of curiosity than anything, what when the clutch is fully engaged (ie pedal fully up) spins constantly in the gearbox all gears and neutral ?
and why placing pressure on the clutch pedal to the point of resistance is felt would either stop spinning or start to tighten up ?

The needle roller bearing on the end of the crankshaft - does that ever produce problems ?

cheers
og

Clutch pedal up- crankshaft, flywheel, clutch pressure plate, clutch friction plate, gearbox input shaft all spinning. if it's in gear, you'll also have your output shaft spinning.

Clutch pedal down- crankshaft, flywheel, clutch pressure plate spinning. clutch friction plate is (relatively) still- the pressure plate is being prevented from clamping down onto the friction plate (which is splined onto the gearbox input shaft).

I've never heard of the needle bearings going myself, all I've heard is that it's worth changing them when you take a flywheel off...

 

[OLDGIT ST]

cheers for that....

on advice so far, think its input shaft bearing

gravelly noise all gears clutch pedal up
gravelly noise at tickover clutch pedal up
pedal pushed down 25mm onwards to floor - no noise

thing is, there was a tiny bit of debris in the bellhousing... small amount of metal shavings and what looks like some gasket material...
release bearing and mount perfect

input shaft seal perfect / no leak
input shaft has approx. 5-7mm of play if rocked about
not sure if this would show anything at all but placed friction plate on input shaft and spun as fast as I could - all smooth barely no noise.
would I be correct that clutch pedal down if it was engine related the noise would still be there ?

cheers
og

 

[ozziedog]

Yes and no, :shock: So not neccesarily. <<< I can never spell that bloody word It does sound most likely apart from a loose flywheel, or off centred during rebuild (orbitally). If it was more of a chatter, you might think about a damaged pressure plate possibly.

Ozziedog,,,,,,,,,,,,, Just thinking out loud and sharing thoughts :mrgreen:

 

[aircoolsteve]

I've just completed a job on a split bus running a 2.0 type4 engine. It had a problem with the input shaft bearing which had disintegrated big time! The needles had come out and wrecked the friction plate and were laying on the bottom of the bellhousing. To get the input shaft some support on these conversions the bearing has to be pressed into the actual flywheel but it is the proper bearing.
It is a rare occurrence for a bearing to fail and it can be a problem getting the engine and gearbox apart if the bearing has dried out, but in this case, you wouldn't be able to select a gear with the engine running.
I have to say that even though the bearing had totally failed, it still made the most horrendous noise and it came out just as you see it here. I didn't damage it getting it out.