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Discussion Starter · #1 · (Edited)
Ciao GTV6 Alfisti,

As per ‘pangolin’s’ pervious thread we’re also undergoing the process of aligning the crank shaft and rear gearbox input shaft to try and eliminate the current tail shaft vibration.

In the meantime, I’d like to clarify whether the position of the central spline has any contribution to the vibration! As per the photo below my rebuilt driveshaft has been assembled differently to an unmolested/original tail shaft and asking the question if any other unmolested, or properly working tail shafts have the same alignment or it’s just random?

Wood Gas Cylinder Machine Pipe


Note that the end spine has a fixed position, so that I’m comparing apples-with-apples
Wood Automotive tire Gas Machine Auto part


Look forward to the feedback. Thanks
 

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Discussion Starter · #11 ·
Ciao pangolin, thanks for clarifying and appreciated all your feedback :)

For the sake of the of the exercise we’ll firstly horizontally allign the crank and gearbox input shaft and reinstall the tail shaft as is and assess the vibration! If there’s still a vibration issue we’ll install the unmolested tail shaft and assess the difference.

Can you please confirm that your GTV6 has no tail shaft vibration issues?

Thanks in advance
Saluti
 

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Discussion Starter · #15 ·
Wouldn't it be best to start with an assessment of whether the driveshaft was balanced or not before taking it apart? My driveshaft is very smooth, so when I pull it apart, it's going back together exactly as it is - regardless of these orientations - doesn't this make sense?
With unknown driveshaft parts, I'd start with Richard's advice of even spacing.
Joe
Ciao Joe,
The drive shaft has been already been balance in it's current orientation by previous owner.
 

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Discussion Starter · #19 ·
I don’t have a pic of my mechanics alignment tool but believe it’s a specially lathed adaptor….I’m leaving this issue with a Pro ✅

As per my original post I’m interested to see if when it’s aligned, whether the configuration of the driveshaft assembly will still have a vibration!
 

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Discussion Starter · #21 ·
Just for the records, it appears that the position of the central spline doesn’t contribution to the vibration as long as the tail shaft has been balance correctly.

The main factor which contributed to my tail shaft vibration is the mis-alignment of the crank shaft and gearbox input shaft and at the same time keeping the central tail shaft mount in its correct position.

Good luck and trust the info helps 🍀
 

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Discussion Starter · #23 ·
Ciao Pangolin,
It's all in the position of the engine and it's mounts as gearbox is fixed. Loosen all the engine mounts and jiggle the engine until it's sitting in it's correct position, you might need to elongate some holes.
Also very important that all the mounts are in a relaxed state (not twisted or stressed) when secured as any tension in the mounts will transfer to the tail shaft!!
Saluti
 
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