2001 Grand Prix GT ABS TRAC OFF Problem?

bigjim_h · #1 03-25-2006, 07:52 AM

I have a 2001 Grand Prix GT 3800SeriesII the ABS and Trac Off came on at the same time. I have seen the posts about bad wheel bearings and sensors. I have replaced both front wheel bearing one left at 65K and right at 85K. Now have 96K and these lights came on. How can I determine the problem. When the front bearing went you could tell it hummed like a SOB. Car does not make any noise, it runs good. This is the only issues (hubs/bearing) I have had with this so far. Any help would be appreciated. Thank You

BNaylor · #2 03-25-2006, 08:18 AM

The best thing to do is get it scanned with an ABS capable scanner to see which particular wheel sensor is causing the problem. Another thing is check the wiring going to each wheel sensor at the the hub. Sometimes you can detect a defective wheel sensor by checking the resistance. It should read around 1K ohms. All you need is a multimeter (digital) in the ohms position. Go across the two contacts of the sensor after removing the electrical connector. Of course if you find another bad wheel sensor you'll need to replace the hub/bearing again.

bigjim_h · #3 03-25-2006, 08:24 AM

Thanks Man I have a buddy that opened a garage recently I think he has all of the Diagnostic tools, this car has been great outside of the problem with the wheel bearings/ hubs going bad.

richtazz · #4 03-25-2006, 09:05 AM

Don't bother with the cheapo white box Chinese hubs. Spend the extra money on the Delco or other US made hubs.

BNaylor · #5 03-25-2006, 09:26 AM

Quote:

Originally Posted by richtazz

Don't bother with the cheapo white box Chinese hubs. Spend the extra money on the Delco or other US made hubs.

Hopefully he didn't use the cheapy white box (generic) hubs because that would explain the re-occurring failure.

bigjim_h · #6 03-25-2006, 05:09 PM

I hear ya guys but to be honest it's time for a new vehicle so and not to impressed with the delco hubs they only lasted 65,000 and 85,000 miles. This is the only car or truck I have owned that has had 2 or maybe more hubs go before 100K. As a matter of fact my 99 Denali has 189K and never had any problems. Maybe just fwd cars?

maxwedge · #7 03-25-2006, 07:43 PM

Improper torqueing of the axle nut leads to chronic failures, not an impact gun job.

richtazz · #8 03-26-2006, 10:15 AM

Like max said, the number one problem (90% or more) with replacement hub failure is improper installation. If the mechanic is lazy and uses an impact wrench on the hub nut, the hub is toast. The hammering action of the impact wrench does three things. First, it can damage the ABS sensor components, causing them to short out and trigger the ABS light. The second, it puts minute dings in the bearing race, causing a rough surface for the bearing rollers to ride on, thus causing a vibration that steadily worsens until you feel it and/or hear it. Third, an impact wrench doesn't tighten the axle nut to the proper spec, which pre-loads the bearing holding it together. Without the proper nut torque, the bearing will pull apart and start to howl or vibrate, and it can mis-align the ABS sensor causing the ABS light to come on. Replacement hubs often require a different torque value than the OEM spec, and mechanics rarely read the instructions in the box. If you torque an aftermarket hub to the OEM spec of 150 ft/lbs from the repair manual/All-Data instructions, instead of the 180ft/lbs the bearing manufacture specifies, it's only a matter of time before the new hub is toast.

BNaylor · #9 03-26-2006, 10:47 AM

There are other factors too. There is a discrepancy in the GM service manuals. Two axle nut specs are floating around. 151 ft-lbs and 184 ft-lbs. Of course, this pertains to the OEM/GM hubs and not aftermarket.

Next GM specifies always use a new axle nut, never re-use the old.

And the most overlooked part of proper torque are the three hub mounting bolts/nuts which must be torqued to 60 ft-lbs. A lot of DIY people and mechanics overlook that part.

But on the cheapy hubs I believe that it is a quality issue. You get what you pay for.

xeroinfinity · #10 03-26-2006, 12:40 PM

Also I hav found that replacing one at a time is a waste of my time. You usually get the other hub/bearing failer very soon after the replacment of the first..
Just get them both and save time and patients. Just my

wlkjr · #11 03-26-2006, 07:01 PM

Quote:

Originally Posted by bigjim_h

I hear ya guys but to be honest it's time for a new vehicle so and not to impressed with the delco hubs they only lasted 65,000 and 85,000 miles. This is the only car or truck I have owned that has had 2 or maybe more hubs go before 100K. As a matter of fact my 99 Denali has 189K and never had any problems. Maybe just fwd cars?

So what do you want for this worn out old steed? Maybe there's some parts off of it I could use on my '97 with 305,000 miles to keep it running for another year. I just replaced the hubs for the first time about three weeks ago and I know what you mean about that humming noise. I certainly can tell a difference in the way it rides and handles since putting the new ones on. Apparently I'm one of the few who hasn't had much trouble with mine. I wish I had a brand new one just the one I have now. I'm going to see how many miles I can get on it until it starts costing me an arm and leg to keep it going.

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