I bought this as-is at Ikea (whirlpool makes it for them) and was told all the parts were there...of course not. So I have found the mounting plate on-line and now need to figure out what the two 1/4x20x3"+/- screws go into on the top of the box (cabinet wrapper W10269453 or W10210836). These screws hold the front half of the unit up in combination with the wall mounting bracket that holds the back half up. Simple enough concept but when I put the screws down in the two square punched holes in the wrapper there is nothing there, ie: no female threads for the screws to mate with.

So what is supposed to be there? The boneheads at Whirlpool and Ikea can't tell me. All they say is what is needed comes with the attachment hardware package (1/4x20 screws, 1/4x20 toggles. washers, sheet metal screws, power supply cord bushing). It certainly can not be the toggle nuts as a 1/4x20 toggle is much larger than the ~11/32" square hole in the top of the wrapper, and everything else is obviously not for this purpose. The installation instructions do not indicate anything either, just the 1/4x20 screws going down through the bottom of the cabinet box above and magically mating with something in the top of the microwave. From my research I am thinking it might be missing some cage nut inserts. Any info/guidance would be appreciated.

So I am correct in that there should be something like a cage nut pressed into that hole from the factory. I can't use washers and a nut at this point as the inside of the wrapper is not accessible without disassembling the unit, and even then, what will keep the nut and washer in place?

Thanks

I got some 1/4x20 cage nuts and they don't come close to fitting in the holes so now what? Attached are some pictures that I hope further explain my predicament.[/ATTACH][/ATTACH]

If I can't figure out what kind of nut or threaded insert is supposed to be there and put that in then I will be forced to do something along the lines you suggest. Thanks again.