Can be several things:
1) runout bearingslots (bearings are loose in the slots)
2) wrong size spacer (eagles use standard 10,3mm spacers, same as each inline wheel)
Space on the bearingslots isnt a big problem as long you use the right size spacers and/or axles.
To test the spacer, put the spacers and bearings in your wheel, exactly where they suppost to be, take the wheel at the bearings between your tumb and pointing finger and feel with your other hand if the wheel have axial movement. In that case your spacer is to big.
If you put the wheel in your fork, tighten the bolt and feel is the wheel has axial movement. If so then your axle is to long.
Both of above reasons will make your bearings rattle also.
If the bearingslots are to "big" then yo only would hear a Click, still with all parts on the right size that wouldnt happen really..
The option to put tape arround the bearing is the last option for a to wide bearingslot.
Marcel