Driveshaft replacement cost

[Volvo8873]

Question, so thanks the horribly shitty winter and not doing my proper full pre trip for sometime I came across my seal on mid driveshaft (photo in above post) had popped off allowing whatever to get into it.

I took the drive shaft off to clean the inside of dirt, gunk, grime and with that being said I have everything cleaned up and ready to put back together and I am curious on how much grease that I need to put into the splined shaft tube? I figured enough to where the grease pushes out the splines when the two units are put back together with the seal not popped on?

FYI this is a Meritor permalube RPL style shaft. The service manual for Meritor does not explain anything on lubing this style.

These are not greaseable driveshafts.

Thanks for any suggestions.