Well now wait a minute.... I replaced my rear springs 6 months ago, the drivers rear, if memory serves, had a plate just like that described inbetween the spring and axle. I asked about it on here and got a few suggestions. One was that this plate is to distribute the load from the additional weight of the spare tire. Right now I don't have that plate installed, cause my spring guy never gave it back, and the truck seems to lean to the drivers side abit. So there might be a reason for it, don't throw it away just yet.