I've set up one Dana 44 and 10 to 15 or so Dana 60, never used a case spreader. I talk to one of the local Dodge dealer heavy line mechanic(before I did my first one) and he said you don't need them I pry the carrier out with two long pointed pry bars, remove the original carrier bearings(if that carrier is going back into the same housing)and install a set of honed carrier bearings I used for setting them up, get the back lash correct and reinstall the original bearings(if there good , if I am going to use new bearings I measure the inner race width and add or subtract the shims as needed to get the same preload as when removed)If I'm installing a new spool or carrier, like changing ratio that needs a different carrier, I use the set up bearings to get the backlash AND PRELOAD SET, measure the width diiffernces on the inner races and compensate on the shims on the new bearings. The Mopar service manuals I have(all 6 of them) say to use the spreader and use .012 to .018 (I think ) preload form zero on the carrier bearing preload, that has worked very well for me I have seen one Dana 60 3/4 ton truck center section where the axles tubes run against the carrier bearing destroyed by something or someone not getting the set up correct I had to take that housing to Summer Bros. to have it fixed, they machined it flat and gave us large, harden washer to use a shim bewtween the axle and the carrier bearings It must have worked okay , the customer never compalined or brought it back, it was in a 4 speed race car that ran in the high nines back in the mid 1970s Buy the case spreader and DO NOT over spread the housings I would buy the other tool also