Oster® brand clipper blades often require adjustment as the result of blade assembly misalignment or damage caused by heat, general wear or misuse that loosens or bends blade assembly pieces. Recognizing this type of problem isn't difficult, as distinguishable shaking and rattling occur when the clippers are turned on, resulting in an uneven haircut. You can usually adjust your Oster clipper blades with basic tools to fix this problem.
Place your Oster clippers on a towel to protect your work area from loose hair or debris as you pull the blade assembly apart.
Remove the blade assembly from the clippers. To unlatch a latch-style detachable blade assembly from the clippers, push the black button on the ledge slightly below the back edge of the assembly in a "forward and up" motion until you feel a click. Carefully lift the assembly and slide it from the metal bar portion of the latch. To remove an attached assembly that screws onto the clippers, remove the screws from the back of the assembly and pull the stationary and movable blades from the clipper.
Clean and oil your blades. On a latch-style detachable blade assembly, slide the back blade half-way out of the assembly to the left and brush away any dirt and debris with your cleaning brush. Repeat on the right side and then wipe the entire assembly with a lint-free microfiber cloth. On an attached assembly, brush and wipe the pieces. To oil the blades on a detachable assembly, turn the assembly over, slide the back blade to the left half-way, oil the rails on that side and then repeat on the right side. Wipe away excess oil with a cloth. To oil blades on an attached assembly, place two to three drops of oil along the teeth on each piece and wipe away the excess.
Adjust the blade assembly. If working with an attached assembly, go to Step 7. If working with a detachable assembly, turn it over to the back rails and look for two metal tabs sticking up from the back connected to the "socket" part of the latch that slides onto the metal bar. These tabs serve as tiny walls holding the assembly in place when you slide it back onto your clippers. If the tabs have moved too far apart—if they bend outward—the clippers shake or rattle because of an improper fit.
Position the jaws of your pliers around the exterior sides of the tabs and slowly apply slight pressure on the pliers' handles to straighten the tabs. Once straightened, re-latch the assembly to the clippers and plug in/turn on the clippers. If the blades still shake or rattle, remove the assembly, bend the tabs inward slightly with the pliers, and check again. If you have the opposite problem—the blade assembly doesn't fit on the clippers—carefully bend the tabs "outward" slightly with your pliers for a looser fit.
Check the flat ledge on your detachable blade assembly socket for an upward bend if your assembly no longer slides easily onto the metal bar portion of the latch. If bent, align the jaws of your pliers above the ledge and below the front of the assembly and slowly apply pressure to straighten the ledge.
Align the stationary and movable blades on the clippers and firmly tighten the screws into place. The attached blade assembly design and the screws control blade movement, and loose or stripped screws or bent blades cause shaking or rattling. Plug in/turn on the clippers. If the blades still rattle or shake and the screws appear stripped, replace the screws or take your clippers to a professional clippers or Oster-brand repair technician. If the blades appear bent or damaged, attempt to unbend with your pliers, replace the assembly or take your clippers to a technician.