870 spindle shaft/front drive wear

[yandeereguy]

doing some service on a new to me 870 mfwd and noticed some play in the front drives (spindle shaft) the up and down movement is significant and willl need to be addressed soon, whats the usual culprit on this bearings? spindle shaft?

Just want to get an Idea of what I might be looking at before I start tearing this apart..