I went to install my new V6/5.29/Detroit All-Pro set up 3rd member into my stock '85 4Runner rear axle. The 3rd member will not slide into the axle. The gears contact the axle housing. Should I just grind a little of the axle housing to allow the 3rd member to slide in? Or did I miss something? Do I possibly have a wrong part? I've never heard anyone mention this.