Front Bearing Problems

[CMS07]

For the 3rd time in approximately 40k miles my front left bearing has went out. When I replace them I get the whole hub assembly which costs around $280 from NAPA. My front right bearing also went out about a month ago (first time). Could this be just bad hub assembly's that I'm getting or could there be another problem that I'm not aware of. Thanks for the help. The car is a 2000 SLE with 127k.

[crash93ssei]

I would say just bad luck with the hub assemblies. What brand are you using and what warranty do they have?

[00Beast]

How is it $280? When I had them look it up, it was $170 at NAPA in New Ulm for the expensive one. Try the Timken's from RockAuto, and use the site discount that's posted in General Chat. $110 shipped to your door. I have about 10k on the one on my car and it's perfect.

[CMS07]

Well apparently they took advantage of me when I bought the first bearing. They did warranty when the second bearing went out. But the third one went around 1500 miles after I replaced it. I'm not sure what brand the bearings are.

[redbaron05]

What happened that led you to believe the wheel bearing was bad or going bad?

[Archon]

There generally will be a moaning or groaning sound coming from that part of the car that starts around 25-30 mph. It may, or may not change pitch with an increase in speed.

[CMS07]

I found out that it was the bearing from a mechanic that I used to live next to when I lived back up in MN.
Whenever I take a curve and turn to the right, the sound would get louder. The moaning sound starts at 20 mph and increases in speed also. I drive the car around 10 miles a week so its not something that I need to get fixed right away.

[Oldman]

Have you changed the suspension in any way? Changing to a wider rim that stands out from the car more puts an incredible stress on the hubs and bearings.

[Ken_W]

[ Note: I learned what I'm about to write while doing research for my Pontiac Montana. Since the 00-05 Bonnevilles use the same parts, I am assuming that the history is the same. If anyone can confirm/deny this, please do. ]

The cause of these repeat failures could very likely be related to your axle spindle nut. This was a common problem on many GM models in the late 90's/early 2000's. In the original design there was a black spindle nut with a couple other parts (washers I guess). GM eventually realized that people were burning through bearings too quickly, and found the cause to be too much torque, unevenly distributed, on the spindle nuts.

More info (this is not new, it came out several years ago):

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TECH SERVICE BULLETIN # 03-04-18-001
General Motors has released a new style drive axle nut for many 97-03 models. This new and improved nut is a torque prevailing style nut (basically it distributes the torque properly) for more consistent clamp load on the wheel bearing. The new nut is silver in color and the old nut is usually black in color. They have also lowered the torque on most all of the models. The original torque for many of these vehicles was 284 Ft/Lbs. THey have dropped this torque to 173 Ft/Lbs, then they dropped it again down to 118 Ft/Lbs. It is very important to check each vehicle specifically to get the correct torque. Anyone who has to replace this hub on the front of their vehicle should get the latest style axle nut. Replacing this nut and torqueing it to the correct lower torque should get you more life out of these hubs.

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If your spindle nut is black, try replacing it with the silver one (I believe the GM part number is 10289657). I checked AutoZone, and they no longer sell the black one (only the silver one shows up for my 2000 Bonneville). The black one apparently required some additional parts (washers?) was was sold as a "spindle nut kit." The newer silver nut is used by itself.

Also; bear in mind that someone using old documentation might still be torquing your spindle nut to 284 ft-lbs. Or, worse yet, if they are using an impact gun to secure your nut then who knows what the torque might be. In several sources that I read it is STRONGLY RECOMMENDED to use a torque wrench on this nut instead of an impact wrench, to ensure that you get the correct torque of 118 ft-lbs. Otherwise, you can expect to keep burning through bearings.

If this information does not solve the problem, you can get low-cost bearings from a place on eBay that offers free shipping and a lifetime guarantee. Most bearings are under $60. I have not tried these, but they seem legit and the lifetime guarantee is there if they have a short life. You can see what they have at this link: http://stores.ebay.com/Auto-Parts-Direc ... 3aSTQQtZkm. (If anybody here has tried these bearings, please let us know how they worked out for you.)

Ken_W

[Archon]

I could find no information on that TSB for the Bonnevilles - at least for the 2000 MY. The torque setting is 118 ft lbs, and the original nuts are silver colored. However, GM says to install a new axle nut any time that it is removed. I'd guess that most people and shops don't.

[00Beast]

I was not aware you are supposed to replace the nuts. Mine were silver, and were flared towards the bottom, eliminating the need for washers.

[Ken_W]

If none of this spindle nut info applies to 2000 Bonnevilles, then I guess the only thing to be gleaned from this is to make sure to torque your spindle nuts correctly, as over-torquing has been known to burn out wheel bearings.

Any other theories regarding the original poster's issue?

Ken_W

[dpnewfie]

I didn't replace my spindle nuts. All is fine so far. Well, its only been a few weeks. However, I did torque the spindle nut to 118 ft/lbs.