Starter not engaging.....

[AmandaW123]

hey everyone, we are having a bit of a problem, the starter on the van was just replaced and now its not engaging right away when we start the van....it just spins for a bit like its trying to catch the right gear then finally it starts....we tried putting a "shim" between the starter and the body that was originally there, but that didn't work...its a brand new starter....please help....