2015 Silverado Body Mount Torque Spec

[ic3man5]

Found this for 2014: http://www.gm-trucks.com/forums/topic/168483-2014-silverado-torque-spec/

 

Anyone know if its the same for 2015? Trying to put step bars on.

[Jsdirt]

Couldn't tell you ... but the body shop that did the insurance repairs on my truck obviously got mine wrong. Truck sounds like it's 50 years old, squeaking and squawking over every road imperfection. Off road it's horrendous - everyone stares ...

[ic3man5]

Yea I'm trying to avoid that plus I guess the nut for the bolts is a pain if it breaks free from over torquing it.

[Jsdirt]

Yeah, definitely want to avoid doing that at all cost. That will ruin your day ...

[Doug_Scott]

Typically bolt torque is based on size of bolt. The torque is designed to stretch the bolt just enough to prevent it from backing off from vibration. You can get metric bolt torque on this site. http://www.cncexpo.com/MetricBoltTorque.aspx

Keep in mind that bolt size is not the head size, a bolt that uses a 13mm wrench is an 8mm bolt (or 1/2 inch wrench is for a 5/16 inch bolt) for example. You are also free to use some blue loctite on the threads as well. Do not use red loctite unless you are happy never getting that bolt out again.

[ic3man5]

That is cool, I didn't know that but makes sense. Assuming since there is a bushing the torque would be lower than what is specified in the chart?

[Doug_Scott]

The bushing likely has a metal sleeve inside it to prevent the bushing from being crushed or compressed to a point that it is no longer a rubber bushing. The metal sleeve ends up taking the space up and becoming solid. So torque stays the same.

[Jsdirt]

Those are grade 10.9 bolts with what I believe is a 8mm or even a 10mm shank - pretty stout ... but the threads up in the body ... I believe that would be the weak link in that equation. Just my opinion, but I think 60 ft.lbs. would be more than enough.

[tbarn]

The nuts near the radiator support are torqued to 52 lb ft. The rest of the body bolts are torqued to 122 lb ft.

[craigerst]

"The nuts near the radiator support are torqued to 52 lb ft. The rest of the body bolts are torqued to 122 lb ft."

 

 

@ tbarn, where did you get this? From the service manual? 122 lb/ft seems high. At least higher than every other thread on his forum.

 

 

[craigerst]

Typically bolt torque is based on size of bolt. The torque is designed to stretch the bolt just enough to prevent it from backing off from vibration. You can get metric bolt torque on this site. http://www.cncexpo.com/MetricBoltTorque.aspx

Keep in mind that bolt size is not the head size, a bolt that uses a 13mm wrench is an 8mm bolt (or 1/2 inch wrench is for a 5/16 inch bolt) for example. You are also free to use some blue loctite on the threads as well. Do not use red loctite unless you are happy never getting that bolt out again.

If I read this correctly, than the body bolt is a 21MM head, 14MM bolt - which according to the chart is up over a 100 lb torque for a 10.9??

[Doug_Scott]

If I read this correctly, than the body bolt is a 21MM head, 14MM bolt - which according to the chart is up over a 100 lb torque for a 10.9??

 

Your wheel studs are 14mm as well. Torque for wheels are something like 140 lb/ft, and they use a cone taper and seat to aid in keeping the nuts tight(the cone when forced into the taper compresses the end of the lug nut making it squeeze the stud). In the body mount I agree with Jsdirt, the nut is the weak link.

 

If you want to see what the bolt is torqued to already, borrow one of those old school torque wrenches with the scale on the handle and the needle on the shaft. The one that basically bends to show you the torque. Use it to loosen the bolts. If you watch closely you will see what it reads just as the bolts breaks free. I have not looked at torque wrenches for a long time, the new digital ones may have a live readout that will do the same thing. Mine is the click kind, no good for checking current torque value.

[tbarn]

"The nuts near the radiator support are torqued to 52 lb ft. The rest of the body bolts are torqued to 122 lb ft."

 

 

@ tbarn, where did you get this? From the service manual? 122 lb/ft seems high. At least higher than every other thread on his forum.

 

 

Yes. GM service Info.

[ic3man5]

"The nuts near the radiator support are torqued to 52 lb ft. The rest of the body bolts are torqued to 122 lb ft."

 

 

@ tbarn, where did you get this? From the service manual? 122 lb/ft seems high. At least higher than every other thread on his forum.

 

I torqued mine to 122 and that seemed correct. Left rear bolt was a bit striped after removing it so be careful when removing them.