[rickfly]

accessory drive seal under the p, main front seal, and the cam thrust block are the normal places, but sometimes it can be the cover to block assly,

 

[rickfly]

use an h bar puller, the nut is rh thread, locking it into a higher gear and blocks is a good way, there is only a shell type bearing in the housing, and it sees little wear, use the speedi sleeve and seal from cummins with the plastic seal guide and DO NOT oil or grease the seal as it is a special type that does not need lubrication. installing the pulley can be a *****, clean the inner bore with emery cloth real nice, heat the pulley in the oven to around 300f and install it with noting there is a lineup dowel to align, slam it as far as you can while using heat resistant gloves, and then install the washer and flanged nut to pull it home, i believe the torque is around 200 ft lbs. replaced a hundred or so of them, and it is a fairly reasonable job, but sometimes the fan and shroud are problematic and need to be removed...