rear drive shaft phasing.. slip yoke, rear joint

is the slip/slide yoke/joint splined in a way that can be indexed differently? It looks to me like the u joint at the slip joint is not quite matched with the joint at the rear diff, as if to be like 1 spline off. (I'm chasing vibrations) So can it be changed, or is it master splined or whatever to only go together one way?

 

If I remember correctly there is an indexing tooth on the slip yoke that makes it to where it can only be put together one way.

Real easy way would be to run a string between the front and rear most u joint (zerk fittings are perfect for tying the string to) the you can see if they line up.

 

Same here. I marked the fuck out of my driveshaft pieces only to find out it will only go one way. Should have save the paint-oh well.

Note that I only took that apart to add a grease fitting.

 

Rather be safe than sorry. Also you could mess up the phase by 180 if you replaced u joints. Which would fuck up balancing.