[Joe Papa Sr]

Hi People,

Well, the Alfa's been behaving pretty reliably since shipping it to S Cal, but now the clutch, when you shift say, from 4th doing 40 mph or so, and slowing down to approach a red light, you shift from 4th to neutral and coast carefully with gentle brake- its right there, as you release clutch with pedal, you get a vibration on the clutch pedal. Also occurs when you take off, shift from 1st to 2nd and of course, the foot is on pedal shifting clutch. you feel an unusual "shake'/jitter in the clutch pedal.

No gear grind though (I initially thought- oh, clutch pivot joint going). Any idea what could be causing this clutch pedal vibration/shake/jitter?

Thanks, People.

 

[spiderserie4]

gearbox mount maybe decided to let go?
Prop flex joint cracked?
UJ's suddenly given up?

 

[Tifosi]

If you're actually feeling it in the pedal proper and not the chassis, steering wheel, or butt dyno, then its likely something that is directly associated/in contact with the hydraulic system.
Specifically working against/at/on the throwout bearing and fork which in turn will backfeed any strangeness back through to the pedal.

EG: Flywheel surface getting lumpy from riding the pedal in traffic or just really overheating it in general making a juddery feel during partial engagement, or pressure plate fixtures coming loose letting things get out of balance by spinning wompyjawed unless fully loaded or unloaded. Pilot bushing could be crapping out too and is allowing the TX shaft to get all wobbly.

There's other plausible things too of course, but that would be the area I'd begin spooking based on your description.

 

[Joe Papa Sr]

Thanks, guys. Helpful ideas. Not sure if I made it clear, or if it even matters, but it doesnt happen all the time. Im sure whatever causes it will cause it more and more frequently- this is just the warning to do something NOW.

Oh, Darren, we can rule out riding pedal as a cause- thats taboo in our family.

Geez, I replaced al those items you mentioned- pilot bushing, resurfaced flywheel, new clutch. But, you know- when I tightened that pressure plate (yes, years ago), I didnt use red loctite, like youre 'pose to. Maybe that could be it........

Looks like gotta take it into an Alfa shop in LA.

 

[jcslocum]

Maybe the slave or master seals kind of dragging and releasing not in a typical "smooth" manner??

 

[Tifosi]

That would be easy enough to test: work the pedal while the car is warmed up, but engine off and sitting static.

I don't see a seal doing it though onnaconna if it drags that hard then its likely about 3 seconds from failure and would most probably have been leaking by this point. Can't imagine one would suddenly start to fit stupid tight after being serviceable for X amount of time though. Usually its more a case of them wearing or degrading and not sealing as well.

Really can't even imagine it being a contaminant in one of the cylinders galling the piston either as that would prolly cause a freeze (bind, won't move at all) and/or fail (holds no pressure, may leak like sieve) in short order too.