Expert: Skip Bollinger - 12/9/2006

Question
the car is front wheel drive and the humming was there before i changed the tires i was told maybe the beaqrings in the hub? what do you think?
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-----Question-----
have a 95 lincoln with new pads and rotors all the way around, I also put new tires all the way around as well on the car. between say around 40-60 mph there is a constant humming in the car and a very slight vibration i can feel it in my feet as i drive!! the humming does go away at around 60 mph!! i am not sure what this could be!! the alignmaent is fine and all the tires were all static balanced.

Thanks

Gary
-----Answer-----
Gary,
  I'm a Parts Professional, NOT a Tech but I will offer these thoughts for your consideration..
  It seems as you could have a couple of problems. You didn't state if the condition existed before you had the brakes replaced and new tires put on. Here are my thoughts on this...
  The "hum", if present before you had the tires installed, could be an axle bearing going out OR a universal joint. It could be low grease in the differential also. IF it has started since you had the tires installed, it could be the tread design on the tires. Have you ever been passed by a Semi and listened to how noisy their tires are? It is caused by the tread design on the tire.
  The vibration could be caused by the axle bearing OR a universal joint getting ready to go South. If your U-joints are greasable, I'd grease them and see what happens. Check the grease in the rear end to make sure it is full. You could have a U-joing going out causing the vibration and low grease causing the bearing to hum.  
  That is all I can think of given the information I have. Again, I'm a Parts Specialist, NOT a Tech but I hope this gives you some direction. Good luck..
   Skip
   HARD TO FIND AUTO PARTS

Answer
Gary,
  If you can find a shop that has a "spin on the car" balancer, you can do the following.
  Have them raise the car about 2" in the air and spin each wheel with the balancing machine. Have them listen, with a mechanic's stethoscope to see if they hear a difference in the sound of the bearings. If they hear nothing unusual, start the car and, on the front, have them listen to the output shaft bearings from the transaxle.
  If you can't find anything with what I have offered above, I have NO IDEA!! I'm sorry. I'm a Parts Specialist, NOT a Tech. Good luck...
  Skip
  HARD TO FIND AUTO PARTS