On the premise that no question is dumb, here goes - I want to replace my OEM valve stem covers with some that have a logo on them. Am I correct that all the TPMS sensing gizmos are in the stem and there's nothing in the screw-on cover/cap and therefore by switching out the covers I won't upset the electronic gods and have to live with alarms & warning lights. Thanks, aloha.

 

The actual sensor is in side the rim attached to the stem where the stem meets the rim.

SO to answer you question. You can change the stem covers with no problem.

The only thing i recommend is that you make sure that they have a plastic thread. You do not want to have a metal on metal thread situation that can corrode and then not be able to get them off. If youput to much pressure on the stem trying to take a metal to metal stem cover off you can destroy the sensor.

 

I got my wife some nice "S" caps for Christmas. The TPMS works just fine with them.

 

Hey, guys - thanks so much for your input and, schatzy62, especially for your comments re plastic thread - excellent point and indeed the ones I'm going to use are plastic. Thanks again.

 

schatzy62 is exactly right.

I put these

on my wheels last Fall and when I had to find out which tire was flat after the tire alarm went on, I had to use a crescent wrench to remove the caps. One twisted off with the end of the valve stem inside, causing the insert to shoot out, giving me an instant tire pressure of 0. Of course it wasn't the tire with the nail in it and I had two tires to deal with. I ended up having to get the entire valve stem replaced.

 

couldn't you just put some lubricant on the thread to prevent it from seizing up and prevent rusting and dirt? ..that's what I'd do.

 

That is what I would do also if the metals were chemically compatible. But in this instance, the aluminum is actually being consumed by the metal of the cap through a galvanic reaction(same principle as electroplating - you have one metal being broken down and molecularly attached to the other metal). The grease may temporarily break the bond and interrupt the current, but eventually there will be a connection and the process will begin.

 

I've got metal caps on mine. Not a problem. I you are worried put a litte anti seize compound on them.

 

NOT bull hockey, what karst said is a provable scientific fact.

I learned the hard way many years ago even using anti-seize compound will only last a short while.

Hopefully you do not loose the caps and stems that you have on your car to this problem. It will be expensive if you have TMPS sensors.

 

Its interesting to see how a chemical process that several entire industries revolve around, namely electroplating and cathodic protection, can be put on a rink with a heifer or two dropping meadow muffins.

Anti-seize compound works great; as good as almost anything else that separates two incompatible metals... until it doesn't; and then you're effed. Just like Balmex on a baby's butt, you've got to keep applying it to make sure its still providing coverage.

Mix two different metals with a dash of road salt, add a splash of H2O, and sooner or later, you can kiss your valve stems sayonara, along with a few benjamins.