Safety Wire!

[piscator]

I bought a safety wire tool and decided to try it out. I found this very handy 2 page PDF on the proper use of safety wire and cotter pins. I thought some of you might like to download a copy.

http://www.smittysrv.com/docs/safetywiring.pdf

I used 10.9 bolts from Belmetric when I installed my trailing arms today. Had to use a carbide bit to drill the holes for the wire. It's probably overkill since the bolts are torqued to 70 ft lbs. And I used a double strand of .032 wire. But I always have been a 'belt and suspenders' man!

This is the first time I've used safety wire and I did it mainly to learn how. I'd love to hear about other places on our cars that might benefit from greater fastener security. Or any other applications you might think pertinent. Please post your thoughts and pictures if ya got 'em.

Robert

[2jmotorsports]

Nice job. Any more photos of how you drilled them?

I safety wired bolts in an aluminum airbox here.

While the airbox is a stout unit with a built in pop-off valve I wasnt too happy about all the bolts in the intake path. I safety wired them so they wouldn't back out. It was a learning experience for me as well.

[2jmotorsports]

Also wired my thermostat after I rebuilt it and replaced the caps.

[OldSpool87]

I thought those thermostat nuts were impossible to remove baseline. A good application would be CV bolts.

[ClickClickBoom]

Originally Posted by OldSpool87

A good application would be CV bolts.

Not really, far more experienced mechanics have weighed in. I tried safety wiring my CV bolts, proper washers is far more important/effective.
Reconstructing Constant Velocity (CV) Joints

This will make your eyes bleed:
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf

The first time I safety wired the cylinder base nuts on a radial engine with .041 stainless, my fingers were punctured and raw, there is a reason they give the new mechanic that honor...

[Superman]

CV joint bolts. RoninLB used to wire them. Makes sense. Drill the hex heads. Whenever I am in triple digit speeds (not often) I think about CV joint bolts. Then I slow down. < wink >

[MBAtarga]

Originally Posted by ClickClickBoom

This will make your eyes bleed:
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf

I'm not trained and have never done any safety wiring, but found the doc interesting. (Section 7-19 for Safety Wire for those interested.) I never realized when chaining connectors, the twist direction of the wire needs to be reversed.

[froggert]

I've had to safety wire bolts for my motorcycles. Make sure you bend the end of the wire back around and down with needle nose pliers. Catching your hand on one is no fun.

[ClickClickBoom]

Originally Posted by MBAtarga

I'm not trained and have never done any safety wiring, but found the doc interesting. (Section 7-19 for Safety Wire for those interested.) I never realized when chaining connectors, the twist direction of the wire needs to be reversed.

Who knows why the FAA decides on stuff. That AC provides almost a hundred years of aviation knowledge/practices. Obviously portions are not applicable to cars, but the mechanical theory is universal.

[T77911S]

a bit over kill on some of that.

CV joints.
i have had 2 come off, 2 different cars.

[ClickClickBoom]

Originally Posted by T77911S

a bit over kill on some of that.

CV joints.
i have had 2 come off, 2 different cars.

Read the thread I posted on CV Reconstruction, long, but some great commentary by the late, great Grady Clay. Fasteners have been a study for me for a long time. 911 CV bolts are a high stress, critical application. I ended up using Nordlock NLX locking serrated washers, they are state of the art fastening technology. The 100MM CV with the small bolts is the most critical application. After having a conversation with the Nordlock Design Engineer, he commented that the torque required by the FSM at 33lbft was danger close to absolute torque for that size bolt. I have been using the Nordlock NLX washer for quite awhile, and when I removed the bolts to replace a torn boot, one actually sparked at bolt loosening.
The difference between loose and tight on these bolts is just a few degrees of rotation, safety wire is not the correct process to prevent loosening of the bolts. Proper process is the key to fastener success.

[LJ851]

[2jmotorsports]

Originally Posted by OldSpool87

I thought those thermostat nuts were impossible to remove baseline. A good application would be CV bolts.

Im not gonna lie I only wired the T-stat caps because the wire holes were already there.

[bkreigsr]

Most of the race cars I've seen wire the drain and fill plugs on the trans. That would be one of my firsts. Also, the drain plugs in the engine, and the oil tank are on my list.
Bill K

[chrisbalich]

I'm in the NordLock camp myself. They're great for CVs and headers where there's either high-stress or a lot of thermal expansion/contraction. They stay tight without over-tightening, yet aren't a terrible chore to remove (red loctite).

[Tippy]

Not to be a Debby Downer, but non of those posted would pass with me.

Used to be an aviation mechanic.

[RWebb]

Originally Posted by ClickClickBoom

... safety wire is not the correct process to prevent loosening of the bolts. Proper process is the key to fastener success.

Exactly! safety wire prevents fasteners from dropping out (and bouncing around on the track) - it does NOT maintain the correct torque

[sandiego]

But if the safety wire keeps the bolt from only backing out say 1/8th of a turn isnt this still better, in conjunction with the wrong procedures which most of us amateurs follow, than no safety wire?

[pmax]

Originally Posted by ClickClickBoom

...when I removed the bolts to replace a torn boot, one actually sparked at bolt loosening.

Yeah, noticed the pffft with a small puff of "smoke" when loosening.

I read in the CV thread, that the NL washers can be reused per the manufacturer but am not convinced yet due to the above.

[RWebb]

Originally Posted by sandiego

But if the safety wire keeps the bolt from only backing out say 1/8th of a turn isnt this still better, in conjunction with the wrong procedures which most of us amateurs follow, than no safety wire?

well, not for CVs - once the axial force from the bolt torque is lost, they will cut thru the bolts pretty quickly, and then use the shaft as a flail to trash anything nearby

the real use (as long as the bolt head is not damaged by somebody drilling them at home !!) is to prevent fasteners spewing out onto the track/road - you can read more in the small book commonly called "Screw to Win"


since somebody channeled Grady above, I'll add that the late great Jim Sims (of National Weapons lab fastener expertise & fame) convinced me on here that the heads have adequate 'meat' to hold up if the drilling is done very carefully

RIP to both, and to BA too