Crunching Noise When I Take Foot off Gas

There is a chance the replacement axle is not a good part. The strut probably would not make this noise.

 

Sounds like it's something to do with rotation so axle shaft end axle shaft nut not not being tight The joint itself failing the hub being cheap junk it is possible usually that takes a couple of weeks usually the rear it's ugly head but I guess it could happen out of the box Jack the car up and put the stands under the jacking points right there where the door seem meets the rocker panels and then put the car in gear or have somebody sit in the car and gently step on the gas they don't have to try and kill it and then left their foot off while you're outside the car listening and watching You may be able to pin it down real good fashion that way by the times that's the fastest way to pin it down of course if you have a lift or a frame table you can do this with the car lifted and all of that but if not then jack stands and all that are the way to go some people are afraid of these antics oh well.

 

I wouldn't be so quick to rule out the struts. There are bearing at the top of those strut towers that allow smooth pivot when steering geometry changes. I've seen many shade-tree mechanics miss those and wonder why they are intermittently getting creeks and pops while driving down the road. They sometimes get stuck to the body side of the strut assembly and nobody looks up there to check; since the strut assembly fell out when you removed the screws.

Hope this helps

 

No the KYB quick struts are complete from upper strut mount all the way to the connection ears for the hub assembly so that's all new so I wouldn't think that would be any kind of a noise maker yet . I mean unless from the factory the upper nut holding the upper strut bearing plate onto the assembly is not all the way cranked down but that would be a stretch.