Since Ive lowered my truck I've been trying to get rid of this steering wheel shake/vibration. I did 4/5 drop mcg spindle/belltech struts and flip kit. I also put wheels on at the same time (retainer clips are gone). So I thought maybe tire balancing, got them balanced same result steering shake around 60mph. So rotated tires just to see if there was a difference, none rode the same. So I thought maybe its coming from the rear. So i crawled under and notice diff pinion is down maybe a little So i added 6 degree pinion shims now its up just a little I also have the tranny spacer. Any body that has experienced this I would really appreciate any tips.

2007 GMC sierra ecsb

 

Maybe an alignment would help?
Or raise and lower tire pressures. Change the front more or less than back as well

 

Yes ,sorry I didn't mention that I did have it aligned

 

Problem solved! It was my front wheel/ tires out of balance Ive had them balanced before and told the tech doing the balancing about my troubles. He did the road force balancing and rotated both tires 180 degrees on the rims and that did the trick! now it rides like a new truck again.