2007 Hummer H3 Horrible metal crunching sound

While driving, regardless of speed, have this horrible metal crunching noise coming from underneath on front end passengar side. It's not a constant but occurs each time I drive. Numerous times. I had mechanic look at- and please forgive me- can't remember exact wording- but something to the affect that there's a"rod" going from tire location to another rod running lengthwise - here is where a "joint" is located. He said that there is suppose to be a rubber "ring" by bearing and mine has worn away. So this is causing metal on metal. So, next day I see same type vehicle as mine at coffee shop. I go and look at this "joint" in this vehicle. Looks same as mine- no rubber ring visible- unless I'm missing something. I would just like to educate myself a bit before going to another mechanic so any input would be deeply appreciated. I'm terrified to drive but currently don't have choice til repaired. Thank you!