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Tail shaft Vibration

Posted: Sun Jul 08, 2018 8:53 pm
by saeb
I found this short video interesting. I'm looking into it further as I'm over it and every change is not a proper fix.

Yes, it is not a 2 piece shaft and no I do not have speakers on the PC but from what I saw it's not just a matter of getting out pinions angle correct but a phasing should also be taken into account.

If both are done and not just one then all vibrations should be gone.

The centre bearing drop kits are bullshit in my opinion and do not resolve the issue entirely. It's a cheap fix that help to make it better and not eliminate it.

As far as I'm concerned the first part of the shaft should be parallel with the output shaft of the gear box so a centre bearing spacer messes with this straight away and changing the phase with a re balance would probably end in tears as it was not balanced that way in the first place.

I have seen other people use a double cardan joint but is this a be all end all fix? I'm unsure and it may be a better solution when the center bearing is lower than the output shaft.

So tomorrow I will measure my pinion and tail shaft angles again as I have already installed 2 degree caster wedges then go and have a chat with a tail shaft specialist.

I believe if the centre bearing is left parallel with the output shaft and the correct cater wedges and phasing is done then it should resolve the issue completely.

Found a cool calculator also. https://spicerparts.com/calculators/dri ... calculatorClick show diagrams.

https://www.youtube.com/watch?v=Idk3BVDVHq4

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Re: Tail shaft Vibration

Posted: Sun Jul 08, 2018 11:46 pm
by saeb
So looking at my below diagram you will the desired angles for either using a double cardan ( CV joint ) or our current setup being all universal joints. I will look into both options and give feedback. although I'm still set on the idea that lifting the vehicle 2 inches is going to have a dramatic effect on the actual phasing of the universal joints also.

Current research has suggested that a double cardan is still more sensitive to load in the vehicle hence why I'm looking at different options.

I'm trying to visualise any axle rotation due to the use of leaf springs and the 3 pivot point in play if any, front pivot and the 2 pivots on the rear hanger.
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Re: Tail shaft Vibration

Posted: Mon Jul 09, 2018 10:25 am
by RossPat
All too much for my brain :roll:

Re: Tail shaft Vibration

Posted: Mon Jul 09, 2018 12:11 pm
by GerryP
I had done some earlier research on this (even though I don't seem to have a problem with mine) and found some good You Tube videos. They explain everything really well.




Re: Tail shaft Vibration

Posted: Tue Jul 10, 2018 12:57 pm
by hoges
Gerry I brought the subject up in February in driveline. please check it out thanks as it sorted my tail shaft issues.

Re: Tail shaft Vibration

Posted: Tue Jul 10, 2018 1:02 pm
by hoges
Sorry Gerry its in Drivetrain