View Single Post
      03-17-2010, 12:27 PM   #27
Cisitalia
No fast lane bandits allowed
Cisitalia's Avatar
United_States
6
Rep
338
Posts

Drives: 2009 135i TiAg 6mt M-Sport
Join Date: Sep 2009
Location: Charlotte, NC

iTrader: (1)

Quote:
Originally Posted by dg1719 View Post
I have been using anti-seize compound on my wheel bolts and brake caliper bolts. I install with a torque wrench. About a year ago, I had a blow-out and it was a relief to be able to remove the wheel with the lug wrench in the trunk.
You really should not be using anti-seize on the wheel lug bolts or caliper bolts. The design torque specification is always with dry fasteners. If you use the dry value torque specification with anti-seize applied, it acts like a lubricant and results in over torqueing of the fastener. Because of this it is possible to exceed the yield strength of the fastener or as a minimum stretch the fastener prematurely or excessively.

If you must use anti-seize, then you need to back down the applied torque by about 20-40% of the dry fastener torque specification.

I don’t use anti-seize on these types of bolts and torque them to the manufacturers recommendation (which defaults to dry values when not specified). I wire brush the bolts if looking a little bad and if really bad you can run an ez-out through the bolt holes to clean them up as well.

Keep in mind wheel lugs that are used on/off many times over the years should be replaced periodically. Also note worthy is, some manufacturers recommend replacing the brake caliper bolts every time they are taken off. Yeah but not many of us do that, but it is certainly a good idea to replace them every once in awhile. That is another good reason not to put anti-seize on brake caliper bolts.

In some applications when it is allowed to use wet or dry conditions, the manufacturer will provide both torque specification values. When the manufacturer designs a fastener application they typically pick a torque value about 80% of the ultimate yield strength of the fastener. That value is typically a dry value with no lubricant or anti-seize. So the wet value will be typically about 20-40% less torque. So you can see it is entirely possible to exceed the yield strength of the fastener with anti-seize, unless you reduce the torque.

OBTW, I used to be a Mechanical Engineer until I stayed in a Holiday Inn Express. Now I am a rock star.
Appreciate 0