Any of you big truck guys know what these are for? Nut tight indicator? I'm seeing them more often on different vehicles buses,garbage trucks ect. Thanks Doug

always wondered what those did.

Waste Management has them on their trucks...... I assummed they were indicators of lug tightness, as in if they moved out of alignment they would be coming loose.......

If they fall of,,,the lug is gone . LOL

I'm not sure but think they prevent from turning counter clockwise if they are loose.

http://answers.yahoo.com/question/?q...1190609AAwbvxl

Keep lugnuts from backing off.....

by giving a quick glance at the green pointers you can tell if a lug has come loose. They should all point in the same direction, unless one points the other way which will tell the driver to check that lug

what are they called, or where would you buy them?

http://www.wheel-check.com/

Thanks Prangle, That answers that,even most truck drivers don't know what they are. They might be good on a boat trailer. Not only do they indicate nut position, but if the temp goes above 120 degrees they blister, ie bearing or brake problem. Their site says a 1000 truck wheels come off a year. I can't imagine driving along and having a 11.00-20 come though my windshield. Doug