Question: My 99 chevy blazer eats wheel hub bearings on a yearly basis. I also have replaced ball joints more than once. Why is this happening and why am I replacing my hub bearings so often?? Please help
Answer:
Possible causes:
1. Improper Torque on installation (see below)
2. Oversize wheels and tires
3. Other worn front end parts putting undue stress on the wheel bearings.
4. Adverse road and weather conditions (see below)
5. Average life span 80,000 to 100,000 miles at most**
Cheaper inexpensive parts usually fail much more often then brand name premium quality parts. Also installing used parts is strongly discouraged.
1. If your vehicle is 4WD, one of the most overlooked and most common causes of wheel bearing failure is incorrect torque of the axle shaft nut. If you have a 2WD vehicle, then this is irrelevant. We are ASE techs who own a repair shop and we have also noticed that GM has changed some of the torques specs since factory. This has resulted in us concluding that GM may have realized the factory torque specs may have been incorrect or they have dialed them in closer to a more reliable setting. Most do-it-yourselfers do not have access to these updated specs or many time install them with an impact gun and this is a big no-no. Also you would be surprised how many techs actually install these with an impact gun and disregard the torque completely. Anyway I hope this helps reduce the number of hub bearings you replace. Other factors include oversize wheels and tires; other worn parts like ball joints can put excessive stress on bearings and other components, and improper maintenance. Thanks again and I hope this helps.
4. Many people would be surprised to learn what chemicals are used on roads to clear ice/snow etc. Many of these chemicals used in northern states are highly corrosive and can affect all undercar components. Parts such as wheel bearings, U-joints, Ball Joints, Tie Rods, other suspension and steering components, Exhaust systems, etc, etc, all can be affected. The customers first thought, when dealing with the same problem over and over again, is usually think that the mechanic did something wrong or is incompetent because they can't figure out the problem. We have seen this happen over and over again, however with a little bit of though and really thinking about the problem, many times you can figure out the root cause of continuous problems. We are in Florida and do not have road checmicals, however every year we get numerous tourist and snowbird vehicles coming down and they come in with some type of problem. Since we do not usually see that type of heavy corrosion on the underside of vehicles very often, we begin to think what could have caused it?? Well it does not take long to put 2 & 2 together and come up with the root problem. One other instance we ran into was a customer always had the bearings and brakes failing on the passenger side of the vehicle only. About every 6 months they would come in with a bearing or brake problem. After they paid us to fix the problem once, they obviously are not very happy with getting the same problem over and over again. We warranted out the parts a few times all along wondering what could have caused this. The right side of the vehicle only. The last time we serviced the vehicle we drove the customer home and dropped them off and to repair their vehicle yet again. Upon pulling into the driveway we noticed the sprinklers on. They were spraying on the right side of the driveway. Well a large light bulb exploded in our head and we asked the customer where do they park their car?? Sure enough the right side of the vehicle was in direct contact with the sprinkler system every single day. Well we didn't have to do anymore free brake jobs after that. They understood the problem and have remedied the problem. We don't have to deal with the problem again because the root cause was removed. The point of the story is please don’t always assume the mechanic, shop, or parts are always to blame. They try hard to fix problems and numerous things out of their control can contribute to such situations. Something to think about anyway with repeat problems. sales@AutoPartsDirectToYou.com Copyright 2007 AutoPartsDIrectToYou.com
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