Vibration 1800 Giulietta

[Zenaga]

Hi there

I have had the propshaft on my 1983 1800 Giulietta removed and replaced for gearbox repairs. Now I notice a vibration. It's not the classic gearlever vibration type of propshaft imbalance, which normally would occur also at idle, but only occurs around 4000 rpm, felt more like a "roughness".

What might have gone wrong? Comments will be appreciated

[116_Veloce]

That assembly is a delicate thing balance-wise, it's enough to miss one notch when you put it back together to cause vibration. When dismantling always mark where the two shafts join, otherwise you never get it right. I suppose you'll have to re-balance if vibration persists. Vibration due to bad rubber donuts is more evident when taking off from stand-still.

[beatle_bayly]

It could be from the R&R of the exhaust. Check the exhaust isn't touching anything and that it's still nice and loose on the rubbers.

Also check that the flange at the front of the gearbox it TIGHT (the one connected to the rear donut). If this item was removed, it may have worked loose. If it lets go there will be much unhappiness

Could also be from a binding locator in the propshaft. It's been ryears since I had one apart, but there is a spring loaded spigot which I think is inside the front end of the shaft. The thing should slide freely but if it kicked off on installation it might cause a vibe.