Shackle bolts

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Feb 19, 2021 | 08:24 PM

triple9jos

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Shackle bolts

I’m not much of a gearhead so this might be a dumb question. Recently installed a Borla exhaust on a 2020 F150 with a friend. Part of the install required hangers to be placed on the rear shackle bolts.

The problem is the Borla instructions were **** and I could only find torque specs for the rear shackle bolt from a Ford lowering kit which called for 173 lbft. We were using a work garage and only had certain tools, including a torque wrench that only went up to 100.

My friend and I cranked the shackle bolts down as hard as we could by hand and I’ve checked the shackle bolts daily for the past week because I’m paranoid. They haven’t budged and nothing is loose.

I guess my question is how important are those torque specs on the shackle bolt? Should I loosen them up and tighten them to spec or should they be good? Is it possible we overtightened them?

Any advice is appreciated. Thank you

Feb 20, 2021 | 08:08 PM

muhford

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From: Missouri

It's very unlikely you overtightened such a large bolt. I wouldn't worry about it. Rust will permanently secure the bolt sooner than later.

In all my years of not owing a torque wrench (I own one now) I've only had one bolt come loose. It was a caliper bracket bolt and I forgot to even tighten it. It was hand threaded and fell off after 2 days.

Feb 21, 2021 | 07:24 AM

SpencerPJ

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If you are really worried, go to a local Autostore, most have a loaner program for tools, and borrow the torque wrench and socket you need. They will want a deposit on a credit card, and return it once you do.
Edit: For reference, you should have been using a decent size bar, think about the lug nuts, 150# for reference.

Feb 21, 2021 | 10:46 AM

triple9jos

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Thanks for the help guys.

We had to use a breaker bar to loosen them and we used the same breaker bar to tighten them.

We are both pretty strong, I haven’t had much of a thought of them loosening, I was more concerned with them being over tight and possibly snapping or something. I’ve checked them daily and they haven’t budged and I don’t see any deformities.

I’ve never touched suspension components before and was kind of nervous to mess with those bolts as I don’t know how important shackle bolts are.

I watched videos of the exhaust being installed and mechanics were just retightening them with impact wrenches

Feb 24, 2021 | 10:13 AM

smokewagun

Cargo Master

Joined: Feb 2004

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From: N. Illinois

I did the same type of install on my 2007 Supercrew when I added a Roush Off Road system. I put the rear spring bolts back in, and cranked them in with a 1/2 drive socket wrench, not a breaker. Never had an issue.

Feb 24, 2021 | 10:35 AM

Robbgt

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From: FL

I have the same exact question on my last gen truck when installing Borla S type. Can't imagine the 15-20s would be much different.

Thread here: https://www.ford-trucks.com/forums/1...rque-spec.html

Bottom line is I went to about 140lbft and called it a day. Never had any problems

Feb 24, 2021 | 11:44 AM

PupnDuck

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From: Staten Island, NY

Just as information, the Ford shop manual calls for the spring to shackle and spring to frame bolts to be discarded if loosened. The re-tightening torque figures are 173 ft/lbs for the spring to shackle bolt and 258 ft/lbs for the spring to frame bolt.

I'm not saying you can't reuse those bolts but Ford's instruction that they should be discarded and replaced with new seems to indicate that the factory torques them at specs that are close to torque-to-yield numbers.

Even if you reuse them, you should invest in or rent an accurate torque wrench.