I look my andis dog grooming three piece blade apart and now cannot figure out where the plastic white bar piece goes.

SOURCE: Hi I bought Oster golden

it's seem that your clipper blade are out of adjustment and also dull, The Lever from what you stated your Lever is worn out also. The only way I can help is to send your clipper and blades to us so we can make all the necessary adjustment, replace the worn out part and sharpen your clipper blades.
I don't know how many blade you have, but we can work some thing out to help you solve your problem. You can e-mail at [email protected]
We have been in sharpening business since 1990 You can check out my rating on Yahoo.com Manny's Sharpening

SOURCE: Brand new blades #10 in perticular leave stripes

hi, new blades are not the answer try replacing the blade drive assembly which is located at the drive end of the clipper and goes from side to side, as the clippers are used this part will gradually wear in width thus not moving the cutter far enough to complete a cut this will produce snagging in smaller blades and tram lines in larger blades like 7, 5, 4 and 3's. All Clipper Parts are available for these clipper repairs.

SOURCE: Putting blade back on my Andis dog clipper

It sounds like you may have a bent hinge which is what the blade slides onto. Please call Andis customer service at 1-800-558-9441 to speak with a customer service rep. They can give you instructions on where to purchase a new hinge or send or clippers in for repair.

Thank you,

SOURCE: How to reassemble blades on Wahl rechargeable unit

I had the same problem and I eventually figured it out. The blade assembly has to be reassembled first then snapped back into place.

1. the bottom part has a little "nub" that the screws attach to
2. the second part is the thin piece of metal with a ridge
3. the white plastic thing, make sure the ridges are sandwiched together
4. the small blade, the blades must face each other
5. the large blade

use the 2 screws to hold the assembly together, once assembled it snaps into place on the clipper. See attached picture for how it should look once assembled.

It's STUPID that this is missing from the instruction guide that comes with the clippers.