Originally Posted by pebbles1472
They are def not rubber. I thought they were metal but quite possibly a hard plastic. They have cracked & the the valve & tpm fall into the tire causing it to go flat. So while I don't necessarily use them to make sure my tires are inflated-they kinda have to be attached to the tire to make sure it doesn't go flat. The repair kit is only $1.99 @ my work so the price isn't the issue. The issue is going down the road & all of a sudden I have a flat tire. Kind of a PITA!
The stock valve stems on a JK are black and made of a hard rubber like poly material. They will move basically as a standard valve stem, not totally rigid. You don't have to have the tpms if you don't want it. You can have a standard valve stem installed, but your tpms light will go on. An AEV Procal can be used to set the pressure to zero and the light will go out. Or, you can use the repair kit or replace the entire unit(s) and you'll probably get another 3-5 years out of them. You can get them for less on e-bay if you want the tpms to work and you'll have a new set up.