Alignment Bolts and You
 

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:

http://i.imgur.com/ft4ALbh.png

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)
http://i.imgur.com/z1BXW0D.jpg

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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.

Excellent post. We need more info in this section like this.

generally speaking, since the rears for toe (mainly looking at) are TTY bolts, the BMR adjustable toe arms just started looking more economical.

same as the arms up top to adjust camber for that matter.

So anytime we adjust alignment we need to replace those two rear bolts?

yes

thats what GM says, two per side so 4 total.

Bringing this thread back from a few months ago. I have a 2018 ZL1 1LE. I assume the torque and replacement specs apply too it as well. But that is just an assumption...

Anyone know for sure or can point me at a source?

Great post.
:popcorn:

Excellent info... I think I am going to print this out and put in the glove box for reference. Thanks!!

Should be sticky.

However I'll add that TTY is asinine for alignment bolts. To me it is just as dumb as specifying TTY for lug studs. Something that's meant to be adjusted or otherwise regularly serviced shouldn't be TTY.

+1 this should be a Sticky

So this would of been useful info to have before I completed my BMR install?? I know every veh definitely needs an alignment post lowering etc, but I tightened the crap out of the bolts I loosened. Neither of the installs I saw prior mentioned anything about torque specs or reuse or replacement of bolts. So, when I do bring it for an alignment, should I bring it to the dealer?? :iono:

This info should also be over in the "Suspension | Brakes | Chassis" forum as well, right?? :gossip:

it could be, but its def great being here. since it kinda touches on maintainence, and wouldn't get lost among some of the "cosmetic suspension" threads...

:thumb::word: agreed X 10

amen