Fasteners, Locktite and Re-Tourqing
 

Last year I went a little nuts (no pun intended) after reading Carrol Smith's Nuts, Bolts and Fasteners. I subsequently replaced all critical suspensension joint fasteners with AN Air Frame bolts using Locktite and Nylocks. Since I open track the car 5 - 6 time a year, I want to do a nut and bolt on the car this summer. My question is: Can I re-tourque bolts with locktite on them or will it permanently ruin the bond thus requiring additional locktite? Thanks for the responses.

Curt

You will need to remove the fastener, clean it off, re-apply the locktite, then reinstall and torque if you want it locktited (is that a word??)
It is unnecessary to use locktite on nylocks.
Steve

I often use the RED Permatex High Strength, which says on the bottle it's for "permanent" installation. I've found the removing or retightening the nuts after installation did not affect the Permatex ability to hold the nut in place "that much".

In fact the "red stuff" is SO brutal it's difficult to remove the nut even after it is totally free of the plastic nylock compound. That red stuff IS "permanent", bonding to the threads very tightly. Instructions say: "Heat or special tools required for Disassembly", BELIEVE IT! This is mean stuff!

Will it weaken the bond if you retorque? Sure. Will it still hold the nut from loosening up? I believe it will! I have found no need to re-torque after using it. But having removed some nuts or retorque some is how I found it. The other colors and compounds of various locktite stuff I'm not sure about. So it may depend on what brand and formulation your using.

My 2¢:
You run a genuine race car, with that much exposure. i would not use loctite on susp bolts. With such nice bolts you must certainly be using proper washers, lock washers and lock nuts as may be necessary. Perhaps you even use bolt stretch length to set the clamping forces, rather than torque. If so, just record and measure the bolt length to prove the force is with you. Easy and non-destructive.

If you try and retorque, you will not get a sensible reading until the loctite breaks and even then it will be grainey, perhaps.

i would regularly re-torque the bolts before each event and begin to document which are getting looser, if any. Take special care to check them very carefully. Some, even, will get tighter, though not often for no good reason. Make sure you are looking at the drive-line, transmission and linkage bolts, also. And don't forget engine mounts, both manifold sets, side-exhaust bits and the entire engine compartment. And your seat bolts, wind-wings (if any), fuel pump brackets, fuel tank brackets...

You get the idea.

F1 cars do not have loctite on their susp bolts.

On the other hand, some few insist on using it. If so, just test enough to ensure that the loctite hasn't loosened, not enough to test the actual bolt torque and crack the loctite joint. If you figure out how to do that, let me know.

We just use nylon lock nuts on the sprint car and have never had a problem with them working loose. Loctite is a great product but can be a @itch to loosen & clean.

I agree with every thing that What'saCobra said except the cartoon.

We are in the logging industry and with the heavy equiptment we have loose bolts are a big problem. Loctite "Red" is a great product, we torque only one time and then we throw the anvil away.

Scott S

There are certainly some excellent applications for loctite, where the issue isn't clamping force, but permanent or semi-permanent nut retention.

Attaching a loose chain link to another loose chain link, where the clamping force and stretch aren't important, but just the retention of the nut and thereby the chains and thereby the load, would seem an excellent application.

Though mind you, i would've thought the strong correlation of tree-hugger behavior, spiking, tree-camping, mother-earthers, endless harassing court suits, refusals to clean the forest floor and flag-burners might've been more logical on this holiday.

But, wisdom comes from experience, not in the university of self gratification. Some say a conservative is just a liberal that's been mugged. Could be, but i've seen spiking damage, up close. Not pretty. Same crowd, IMHO. Along with current PETA leadership.

Flag burning is the proper way to dispose of an old flag. But, it depends on the animus. Private and with reverence/respect for dads, brothers. grandfathers and uncles that paid the price.

Happy Fourth of July.

Curt,
Also remember some hardware applications do not require much torque.... such as shear loaded clevis type bolts. Also painting the nut and threads with a "witness mark/ stripe" makes it pretty easy to keep an eye on areas of concern.
Steve

Some good points to consider. I guess I kinda went a little nutty. Some joints have locktite, nylocks, and lock washers - hehe. I will try re-torquing the locktite joints at 80%. That should not disrupt the bond unless something has backed off. I usually nut and bolt the car at least once a year. This will be the first since installing the air frame bolts. The witness mark and journal of loosened fasteners are great ideas. FYI, I also use safety wire on the brake and hub pieces as well as some other ancillary items. I think I enjoy working on this car more than driving it :)