So there is a lot of talk about the bolts related to alignment being reusable or not. Also Ive seen improper torque specs flying around, so this post is to clear things up, basically what does GM officially say?
Why are torque specifications important?
Torque is the only thing holding your alignment if you do not have proper preload on the joint then your alignment can then drift (fall out of spec)
What is a a TTY/TAY(Torque Plus Angle to Yield) Fastener?
Front:
For further clarification I submitted a question to GM though SI (Service Information) department about the front bolts here is there reply.
Rear:
So what about the rear? No one talks about the rear!
Picture from my 2017 1SS 1LE of the rear alignment bolts (Drivers side rear looking inward)
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Conclusion:
Front: The front shock bolts are not TTY/TAY(Torque Plus Angle to Yield) these are TA(Torque + Angle) fasteners and
can be reused.
Rear: The two bolts that adjust the rear alignment are TTL/TAY bolts and
need to be replaced anytime they are loosened. Nuts can be reused
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Torque Specs
Front Strut to Knuckle Bolts (Lower Shock Bolts)
110 ft/lb + 80-95 degrees
Rear LCA TTY/TAY Bolt
85 ft/lb + 75-90 degrees
Rear Toe Link TTY/TAY Bolt
52 ft/lb + 105 degrees
Part Numbers:
Front Shock Bolts: 11547494
Rear Camber Bolt: 11547215
Rear Toe Bolt: 11611276
*Part numbers from "That GM Parts Guy"
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Disclaimer: All torque and bolt information in this post has been provided by GM though GM SERVICE INFORMATION (GMSi) as of 07/20/2017 unless otherwise stated. This post may or may not be updated if changes are made to the specifications shown above after the posting date.