Out of phase prop shaft
 

How would this manifest itself. Would it cause noise or vibration? I ask because when I refitted mine i got so exasperated trying to line it up whilst lying on my back under car that when the splined shaft finally after many attempts,entered a bit out of line I let it go at that. Now I am experiencing a slight vibration and slight rasping noise under acceleration, difficult to explain. i have driven about 2000km with it like that and think that i might need to investigate it fully.

You could indeed get drive line vibration from a misaligned propshaft.

The splines on my PV's propshaft have an arrow and a raised dot which you are meant to align. (Tis Hardy Spicer)

If you remove the propshaft it is worth while feeling the universal joints (UJ) for either looseness or stiffness - either can also cause strange vibration. If you are not planning to remove the propshaft you might be able to feel slack in a well worn system by holding one end and trying to twist the other end. Not the best way but might give an idea where problems might be.

The resilient centre bearing mount is also a possible problem if it is worn.

When was the last time you greased the UJs?

10cc
 

On these 2 section props the yokes at the end of each section should match. As a result the front and rear of the whole prop end up 90 degrees out of phase.
Yes sometimes props that have been shortened end up slightly out of line and this can lead to vibrations.
That's what I understand anyway....

Looks like I will need to crawl underneath again. Any chance of a photo of the marks? I like to know what i am looking for.

Arcturus;

Observe relative position of UJ yokes when reassembling...UJ yoke of Driveshaft front section should be in-line with yoke of rear section front UJ, as a function of Spline Joint insertion (relative position can be adjusted to allow this by leaving gearbox in neutral such that Gearbox output shaft [and front Driveshaft section] can be easily turned, OR lifting rear tires from ground to allow turning Diff input Flange, OR some combination of both, to bring the Spline Joint into the preferred angular position).

Final assembled position should be as shown here at green.
http://www.sw-em.com/Drives1.jpg
Source: http://www.sw-em.com/Driveshaft_and_U-Joint_Notes.htm

Note also that misalignment can be at angles other than 90 because of the multiple angles (teeth) spline joint can be inserted.

Good Hunting!

Yes, it was only one spline out of phase and I was hoping it would be OK at that but I guess not. Back under! I'm getting too old for this.

3 degrees seems to be the magic allowance before phasing vibrations become an issue so even one spline out is a problem which should be corrected.

3 degrees is not very much and presumably could be the result of a twisted propshaft, rather than one which has been "mis-splined". I don't know how you spot that though!

Correcting the phasing on my Amazon certainly eradicated an unwanted vibration - I hope it does the same for you!