Oster Classic clipper

Be sure to oil the blade and install it with the clipper running so that it seats correctly

normal for clippers if the hair is long or thick
oiling is done with the clipper running
Change over from steel clipper blades to ceramic blades as they run cooler and stay sharper for longer
just place a small drop on the blades and let it work down
AS for others
make sure that the filter in the handle is clear of hair and the same for the vent under the hand
Other than that you can take out the 4 screws and put a small amout of oster grease around the wheel and drive pinion as it can get out and run dry
go to the manufacturing web page and download the pdf version manual

Hope this helps, this is a tongue guide, you hopefully recognise it on your blade. If they are not paralell, then adjust them with pliers, both need to be perfectly vertical. When you put it on the clippers push the latch in as you close the hinge.
If it still wobbles then the next fe wthings need checking
1. The hinge screws on the clipper are tight, located either side of the hinge on the clipper.
2. The drive lever may be worn, thats the maroon peice of plastic sticking up at the top of the clippers, it moves from side to side when clippers are running.
3. If all seems fine up to now, your clipper should be fixed under warranty as it will involve changing parts covered by the warranty.
www.sheareaseltd.com

The part that holds the blades on came loose on my Classic 76 clipper. It turns out that the two holes for the inserts are too big. I fixed the problem by removing the inserts from the clipper body (easy since that is the problem), cleaned the inserts and holes in the clipper body and super glued the inserts back into the holes. Be careful not to use too much glue! It only takes a little.

if the problem arrears to be with one blade on several clippers it sounds like you need to send the clipper blades for sharpening.

Are you sure you have Andis A5 or did you mean Oster A5 Clipper, if this clipper is A5 Clipper, You need to check the Lever for wear, The front of the Lever show wear on both side, Like white color and is not squad this Lever is worn. Need to replace. This Lever moves the blade side to side fully. if the Lever is worn the blade will not move fully side to side and the cutter blade the smaller blade will stay in the middle with hardly no travel to side to side and will not cut the hair even if you purchase new blades. Also I would like to mention if the Oster Locking Hinge is worn out and don't have the require tension to hold the blade in place the blade will not cut. How do you test the Oster Hinge on a Oster A5 Clipper,
(1) first close the hinge, in close potion with your finger nail try to open the Hinge, if the hinge slightly open or opens loose the Hinge is worn. if the Hinge is good it will not open or move and your nail may just brake your nail.
Many of my customers run into this type of problem, and the problem can be solve easily by checking these parts first.
One more item I would mention here if replace the A5 Hinge make sure you get the A5 Hinge not the Oster 76 Hinge they are driferrent, The A5 Hinge has on the back two wire's sticking out that fit on the Oster Latch for the A5 Hinge, the Oster 76 Hinge would not have these wire's on the back. I recommend replacing the Latch when you replace the Hinge. I hope this helps any body that have a A5 Oster clipper or A Oster 76 Clipper.
I have over 20 years in the repair business of Sharpening & Clipper repair. Mannys Sharpening 323 263-4697

Oster Hinge

A5 Latch

Ok turn your clipper on and hold it still in one hand whilst with the other hold the cable near the end of the clipper and bend it, rotate and twist if your clipper cuts in and out you have a break in the cable which is tricky to fit but our web site Help section can help.

If possible try the blades on another clipper just to make sure the clippers are ok, otherwise it sounds like a sharpening problem.

Here is schematic and instructions for service and repair. The model in the picture is the A5 however it is the animal version of the classic 76.
http://www.peasridge.co.uk/clipper-advice/clippers-products-oster-a5.shtml

How do I do maintanience on my clipper to keep them running good