Suspension retorque

[Danny15l]

Keep in mind that every joint is going to have a torque-to value, and then a residual torque value, typically about 30% lower than the applied torque. That initial torque is with a brand new fastener, and if the fastener is selected correctly, is going to stretch when you hit that final torque number, holding everything tightly together. It takes more energy to stretch it that first time, thus why residual torque numbers are lower than torque values. Also, the torque spec is typically +/- 15%, so a 41ft-lbs nominal is actually 34.85-47.15ft-lbs. And taking a 30% reduction for residual, and you'd expect the fastener to be 24.4-33ft-lbs.

Yes you could have not explained it any clearer.

Few years back I had Mavis do a tire rotation on a Subaru I was driving. Pulled into my garage, slammed the door and a lug nut fell off onto the garage floor. Now I do my own rotations and if I take any vehicle anywhere where they need to take my wheels off for any reason I retorque immediately when I get home.

Im sorry to hear about that! yeah I’ve been the same since ever since les Schwab forgot to forgot to install Cam bolts with my new upper control arms. Driving in the winter at that time was crazy.. No issue in checking the work of other people. Especially when the mechanics/technicians are only 20 yos. I deal all kinds of quality assurance stuff at work. I work in manufacturing that deals with products going into peoples bodies. You could think of the safety measures that come with the job… quality control issues as well.

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[Marpater]

I have to ask, when retorqueing your suspension where you using an extension or a flex knuckle?

 

[Danny15l]

I have to ask, when retorqueing your suspension where you using an extension or a flex knuckle?

Each bolt was tightened using a 1/2” torque wrench with a 1/2” to 3/8” adapter and 3/8” socket size. The adaptor is maybe 1” long.

 

[navsnipe]

Few years back I had Mavis do a tire rotation on a Subaru I was driving. Pulled into my garage, slammed the door and a lug nut fell off onto the garage floor. Now I do my own rotations and if I take any vehicle anywhere where they need to take my wheels off for any reason I retorque immediately when I get home.

I stay far away from Mavis. My last visit to them was in 2008. Their balancer machine and tech made my new tires feel like old tires.

While I was there getting new tires on my car I saw them trying to do an oil change on a Subaru Legacy. They drained the transfer case oil instead of the engine oil and then put five more quarts in the engine. Luckily the tech checked the dipstick before starting the car and was very surprised. Needless to say the manager was on the phone with the local Subaru dealer trying to figure out which drain plug goes to what.

 

[JDG]

That’s a little concerning. Imagine being an older gentlemen and not being able to crawl under as easily to check things out. How much off roading have you done, in a percentage? I have done maybe 5 miles of off roading total in this truck.

I agree, was very concerned. And honestly; I only happened to notice it while airing back up my tires after spending the day on the beach in Hatteras, NC. I doubt I would have noticed it until the bolt came out which could have been catastrophic. At this point, I think the truck had maybe 3,500 miles on it (this was back in December 2021) with maybe 5% being offroad (mainly beach and fire roads).

The truck is getting this suspension work done this week since my windshield decided to spontaneously crack along the full width which I am trying to get covered under warranty. I asked them to check torque on every suspension bolt so will be interesting to see if anything else is loose/not torqued to spec.

 

[Aonarch]

Where did you find these torque values for the front suspension?

Post up the link or a screenshot...

As posted, the service manuals have the values, but here are a few for the front.

Upper ball joint 46 ft lbs OEM
Aftermarket UCA upper ball joint 60-66 ft lbs
sway end link knuckle side 85 ft lbs
axle nut 221 ft lbs
coilover upper nuts 41 ft lbs
coilover lower nuts 66 ft lbs
brake hose 18nm or 159 inch lbs
tie rod nut 35 ft lbs
UCA long bolt 122 ft lbs (With suspension under load, place a jack under LCA)

 

[JDG]

As someone who had this happen on my Tremor with just a few thousand miles on it, the fact that bolts were loose does not surprise me one bit.

Note that this is my driver side leaf spring bolt. The nut completely fell off. I had to tap the bolt back in and drive about 50 miles back to civilization, pulling over every few miles to check that the bolt hadn't backed out. I am running a nylon lock nut from an Ace Hardware with plans to go to dealership to have nut and bolt replaced (since bolt is torque to yield) as well as have them check every suspension bolt on the truck.

Definitely caused me to lose some confidence in the build of this truck..

Update to my situation (similar to OP): Nut, bolt and bushing replaced in rear leaf spring @ dealer. Dealer checked every suspension bolt via factory torque spec and everything else was correctly tightened. Spoke with tech and none of the bolts/nuts moved.

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