The bearings on the front passenger side keep going out. What could cause this?

If the bearings are not set in correctly or they are damaged by the pressing on the inner race when fitting they will fail, they must be pressed in square only by the outer race and the drive shaft must be torqued up correctly as well.

Jack up the front the car with both front tires off the ground put the car on jack stands. Then put the transmission in neutral then put one hand on the front coil spring then spin the tire as fast as you can with the other hand. If the front bearing is bad you will be able to feel it in the coil spring. Compare the left to the right. Let me know what you find.

STUPID QUESTIONS

ARE YOU LUBRICATING THE NEW BEARINGS?---DO YOU KNOW THE BEST TECHNIQUES?

I KNOW LITTLE ABOUT YOUR CAR,

DO YOU HAVE A REFERENCE TO GO BY?

WHAT PROCEDURE ARE YOU USING TO PRE-LOAD THE BEARINGS?

THE MEDIC

First, if you dont use a QUALITY bearing, the chances are it will fail early! And I actually prefer a scrap yard (OEM) bearing in spindel tested by me(spin it, is it silky smooth without even a HINT of imperfection) to new cause it's easier to install and no chance of screwing up install and making it fail early! Bad install can cause early fail also.

Inspect the driveaxle CV Joints and Boots