I build on average 150 Dana rears a Year, I give a warranty on all on road rears. I rarely use a case spreader to take them out.. But.. I always use one when Installing the case to get proper pre load with out the bearing races digging in to the housing. The only time I dont use the spreader is When installing in the front of a 4x4. The leaf spring is in the way of using the spreader.Bottom Line
I would buy one, Mark, Greensburg Machine&Driveline