I'm in the process of swapping the motor in my truck. After it was removed I noticed some fresh oil in the bell-housing, any idea as to where it could be coming from? Easy fix?



Thanks (:

 

Rear main engine seal or trans input shaft seal.

 

This.

These are the only two seals that would allow oil to flow directly in to the bellhousing.

Since you have the engine out, yes its an easy fix. Replace both seals. The input seal will require you to remove the input shaft collar.