How do I prevent my guitar's input jack from loosening?

"Try nailpolish?

I used nailpolish a lot inside computer cases, used special shades to show tampering, or just clear ro set strews in place. comes off easy enough even without nailpolish remover.

Just borrow some clear overcoat and give it a shot on the nut of the jack"

"There are different grades of Loc-tite™ Thread locker available. Red high strength, Blue medium etc. Normally you apply a small amount to each part before assembly. Also there is a penetrating grade that you apply after assembly. Be careful not to get any of the product on plastic parts or the finish of your axe as certain plastics will be damaged.

I have used teflon tape to prevent dart shafts from coming loose from the barrels and many players use small ""O"" rings which compress and work much like a lock washer does keeping tension between the shaft and barrel.

As a last solution you can try turning your amp down!! ; )

Rok n Roll!"

Lock-Tite thread locker. It's cheap and keeps the nuts in place.

"I wonder if the Gibson SG's have the same problem. It could be a matter of cheaper parts.

Another suggestion would be to stick a small piece of paper in the threads to engage the nut better."

Here is what I did. I took out the jack and stuffed (really hard) steel wool, the stuff you clean pots with, into the screw holes. Then the screws fastened real tight. Much better than glueing which is not very reversible!

try installing a lockwasher between the nut & flat washer. They are fairly flat (not like the split type used on mechanical machines etc) and are radially serrated either along the outside or inside.