My u-joint nuts go on by hand... If I remember correctly, they were sorta squished when I first took them off, so they wouldn't come undone while driving. When I put everything back together, I was careful to mark the shaft-to-differential with white paint, and tried not to overtighten the nuts. But when I drove the car, it wanted to rattle to death at around 45 mph, and just got worse with a rhythmic pulsing/wavering sound and vibration. I got home, loosened the nuts DANGEROUSLY loose (maybe hand tight then 1/2-1 turn, and drove it and made it to 80 without any vibration (before I chickened out...probably SHOULD have chickened out way sooner ). I don't want to leave them on at approx 4 ft/lbs. Can I put them in a vise and gently squish them and then tighten them up to torque specs, or should I buy new nuts (CAN I buy new nuts?) that already have that squish to them?
Buy the pre-crimped nuts that are fresh. Yours sound like they've lost their temper. Yeah, that's it...they are angry! Anyhow, if you can't find those (Ace Hardware has them) and you have enough length on the bolts you can use a lock washer on them. Many stock ones have lock washers and even my Moroso ones did. Hope this helps!
I found them at O'Reilly in the help section, bought the 2 straps and 4 nuts, came with lock washers. About $6 all together. Also bought a 3/8" drive torque wrench so I can get them the right torque, and not guestimate... NAFORD, you at work today?