Using never-seize on lug nuts

[Stan]

I can see why the paint problem came as a surprise. Urethane paint tends to set up almost as hard as metal and one would not expect about 80 ft/lb  of torque on five studs would crush the paint under an aluminum wheel.

It is curious why re-torgueing  didn't work when the trailer was new but worked later on. Presumably the crush occured on the initial torqueing.

[kyle4501]

My guess is that the movement between the rim % hub was scraping the paint away. You may be surprised at how much trouble a few .000001" of movement can cause in clamped parts. BTDT

[Stan]

Kyle: I don't think ten millionths will have much effect on wheels with tapered holes. That would be less than the stretch in the studs. Trailer wheels are not like drive wheels, there is nothing trying to rotate the wheel on the hub

[kyle4501]

Good point Stan, but I'm not talking movement in the direction of the studs. I'm talking about movement perpendicular to the studs (the rim sliding against the hub).

The weight of the trailer puts a shear load on the assembly. For a ~24" dia tire, that is ~840 cycles per mile. It doesn't take long for those cycles to add up & the movement of the high spots to work their way thru a few thousandths of paint.

My steel budd wheels are 3/8" thick, If the nuts are tightened to 2% yeild of the stud, the stud will stretch .0075". But, since nuts are softer than the studs, you will strip the nut before you get that much stretch. (I gotta figgure those people who are having to replace the studs frequently are over tightening them, but that is just my guess.) So, If the paint is .004 thick, that is a significant reduction in stud stretch. That's one reason why the lugs need checked after being returned to service.

There is a lot more going on in this type of joint than most realize. We haven't even mentioned loss of preload due to the torsional relaxation of the stud (applying torque to the nut twists the stud a little. In use this twist can relax & reduce the clamping force. - But this is usually a very small issue that doesn't make much difference when compared to other issues.)

[Barn Owl]

More about bolts than we would probably ever need:

http://www.boltscience.com/pages/info.htm

Home page for Bolt Science (This site could keep you busy for a while):

http://www.boltscience.com/index.htm

[Tony LEE]

"Trailer wheels are not like drive wheels, there is nothing trying to rotate the wheel on the hub"

Brakes?

[gus]

happycamper,

I use anti-seize so I CAN get the lug nuts off, not to make it easier. I though I made that pretty clear.

You wrote a lot of interesting stuff, some of it a bit off the wall, but didn't say anything about anti-seize actually causing wheels to fall off.

Barn Owl,

The Aeronca 7AC is not a lot different from a Piper J-3 Cub except it is soloed from the front or rear and the Cub only from the rear. I started instructing in Cubs many years ago and really like them but think the 7AC is a bit better and it is quite a bit faster.

I've done quite a bit of flying in the east, got my multi-engine, instrument and CFI ratings at Zahns airport on Long Island and flew around CT quite a bit. The airways there weren't quite so congested then, it is really a mess now.

Don't just think about flying, do it. It is never too late!! If you're ever down in Ark drop me an email and we'll go flying and talk about buses.

I almost forgot to tell you, I got my 4104 from a guy just SE of Roanoke last Aug.

[NJT 5573]

Well, the paint on the wheels is a good story. My steel wheels are painted on both sides, go figure. Only a jam nut holds the wheels and hubs on at the bearings and it runs in gear oil. You set the bearing by pulling it until the wheel won't turn and then back it off about 30 degrees. Wonder what percentage of that .03% was not lug nut related but jam nut problems, releasing drum and all? I'd be afraid of legal BS if I didn't have a large ins. policy in my pocket. THATS what the attorneys are after and everyone should have a million $ policy out there for them to chase. Your ins. co. will take care of the rest. I don't scare easy but i'm not stupid either. Trucks normally run 1-5 million liability. As a group, I understand we are somewhat elite with our outstanding safety record. Insurance is cheap. Buy the uninsured motorist in case you are badly injured and your damages go over the $25,000 lots of people are driving with. Don't forget to help the engineers merge!