It is important to get good serrated lock nuts (not sure what comes with the kit but the ones you get separate are what I use.
http://www.tlracing.com/Products/Def...odID=TLR336000
The kit ones are sometimes not the same cut serrations. If you use the ones I linked to above you should only need to tighten a couple "clicks". If you over tighten too much you will wear through and break the center out.