OK not a Yukon but my 98 express work van is having an issue with the starter. So I bought the van about 8 months ago with a sheared flex plate, I had a shop change the flex plate and got truck back. It started well since but always with kind of a funny noise from starter. Friday the starter started acting up again and sheared the flex plate. After removing the flex plate I noticed that it's slightly bent. We put a new flex plate and starter on and now there not lining up together. As you start to tighten the bolts to starter (staggered pattern) it tilts the starter down in front and up in back causing the starter gear to not reach flex plate when engaged