My 1999 Malibu (V6) has a slight hum when I drive down the highway - it
sounds similar to the hum you get when you have agressive tread on your
tires. You can hear it at almost any speed above 20 or 30 MPH, but it is
more obvious as you speed up. I thought it was the tires because I noticed
it about a week after putting on the winter tires, but when I stopped at a
tire dealership, they took it for a test drive and told me they thought it
was the wheel bearing (probably on the driver's side). Given that my winter
tires have only 6000 miles on them, I am inclined to believe it is a wheel
bearing. a tire dealership - they test drove it, and told me they thought
it was a wheel bearing on the driver's side.

I started calling around to find out what a wheel bearing would cost. The
GM dealership wants $501 CND for parts, Kal Tire wants $300 CND for parts,
and Napa wants $235 CND. A fourth place told me that the rotors can be
integral to some of the hub assemblies, and consequently prices can be high
(and they won't know until they get it apart). Are there different hub
assemblies available for this car, or do the prices just vary that much?
Given the spectrum of the prices I have been quoted, I am very leary to take
my car to anyone - I'd rather do it myself.

Is there any method a "do it yourselfer" can employ to ensure that the
problem is the hub assembly - the parts are so expensive I don't want to be
wrong. Will a garage have better tools for diagnosing the problem, or is it
basically a trial and error process based on an educated guess? In the
past, I have been fooled by where sounds appear to be coming from. In this
case, it really sounds like the front, driver's side wheel.

I bought the factory manuals for this car off EBay a while back. The
manuals indicate that you need a "Front Hub Spindle Remover" to pull the hub
off the axle. Is there a do it yourselfer method for removing the Hub
without this tool? Does the new hub come with the wheel studs in place?

Does anyone know the size of the drive axle nut - it looks bigger than
anything I have in my socket kit, so I need to go buy a deep socket.

My ABS light came on this summer (about 2 weeks after spending $300 to get
it fixed). This seems to be a common problem in this newsgroup. Is it
futile to try to keep the ABS working on these cars? I assume I will have
easy access to the ABS sensor when replacing the hub - I am curious how much
these sensors cost, and how you test them to see if they are working? My
rotors are warped and I get vibration when braking - could this cause the
sensor to go bad? I have been reluctant to replace the rotors because they
don't last very long. Is one rotor better than another?

Thank you,
Chris

Lots of questions...

Rubbish! While some rotors are part of a bearing assembly (mostly light
trucks) this is NOT the case with the Malibu. Ignore this fourth place and
never buy from them again.

The prices vary that much, shocking isn't it? There are different
manufacturers, but they all do the trick. I changed out two sets on my old
Cavalier (10 years apart!) and the "el cheapo" white box assembly turned out
to be the very same SKF bearing found in the fancy box. Hmmmmm.

Very wise!

Unfortunately, you may be fooled again. A wise and experienced mechanic once
told me that I should listen until I was sure what side the bad bearing was
on. Then get a friend to listen until he was sure what side it was on. Have
the car test driven by a third person and when we all agreed what side had
the bad bearing... pick the other side. Y'know, he was right! Sorry, that's
my best advice.

Other than the Torx driver to unbolt it, I'm not sure what tool they could
be talking about. Once the axle nut is off and the hub unbolted from the
car, it should drop off with a light tap. If it was stuck on the axle (?),
any old bearing puller should do the trick to pop it off. Anybody else know
about this "Front Hub Spindle Remover"?

Yes, the hub, or "wheel bearing assembly", is the full meal deal. Bearing,
hub, studs all in one. On the up side, it makes repair a simple and quick
job. On the down side, it costs a lot more than a standard $25 bearing.

I think it's a 36mm, but you can't use a standard deep socket anyway. It has
to be thin-wall to fit in the recessed hole - you can thank the GM engineers
for that one. The good news is that they are readily available at the any
auto supply shop for $10 - 15. The dealer has them as well, if you have too
much money in your pocket and are looking to lighten the load.

I'm not sure about the ABS sensors, I haven't had any trouble with mine
(knock on wood!). As for rotors, I bought the absolute cheapest rotors and
pads that I could find. I made sure all the brake components were well
cleaned and lubricated and then followed the manual's instructions to the
letter (including torque specs for the wheel lugs - a first for me!). I
honestly have not had brake problems since then (last March). A coincidence?
Perhaps, but certainly worth a try.

If your rotors are severely warped, it seems to me that it could indeed have
an adverse effect on an ABS sensor... just a thought.

Good luck,
W

Thank you for all of the information. Is the hub and bearing assembly
identical for all 4 wheels? It appears that way in the manual. If I
install it on one wheel, and the problem doesn't go away, is there any
reason I can't try the assembly on a different wheel?

Does a shop have more tools at their disposal than the back yard mechanic to
make a CORRECT diagnosis of whether my "hum" is a wheel bearing, or some
other drive component? If so, I don't mind taking my car to a shop. But,
if their diagnosis is based solely on a test drive, then I will do the work
myself.

Chris

"Wes Whitlock" <wwwhitlock (AT) ns (DOT) sympatico.ca> wrote

The two front ones are the same and the two back ones are the same, but they
are not the same as each other. Technically you could install it on one side
(save the old one) and if you still hear the sound, re-install the old
(good) one on the other side. This would be a bit of work, but not
impossible.

A mechanic would do a road test, but would follow it up by putting the car
on a hoist and checking for noise and play. You could do the same with a set
of axle stands, but it does come down to the mechanic's experience and
skill. If the bearing is really bad, you would notice it right away when you
spin the wheel with the car in the air. If it's marginal, it might be
difficult. It only costs a little time and effort on your part to try to
pinpoint it yourself, give it a shot. If you're still stumped, try and find
a garage that would do an inexpensive diagnosis for you.

Good luck

"C. Bailey" <reply (AT) newsgroup (DOT) com> wrote

Thank you,

I may give this a try - hopefully it goes smoother than my last project
which was fixing the speedometer on my 91' Dynasty. Believe it or not, most
of the time the speedometer would only work with the high beams on. It
would do 0 to 60 MPH in about 1 second

Is Napa one of the cheaper places for parts? I'm in Canada.

Chris


"Wes Whitlock" <wwwhitlock (AT) ns (DOT) sympatico.ca> wrote

I'm in Canada, too - Nova Scotia. I find NAPA to be one of the more
expensive places (besides the dealer!). They're a large chain and always
seem to have the right parts in stock, but I find that the convenience of
not waiting for an order costs a few bucks more. I normally call around to a
short list of local suppliers for my parts. Different places are cheaper for
different things and I have half a dozen favourite spots that I try. The
grungiest, most run-down places often turn out to be the best.

0 to 60 in 1 second in a '91 Dynasty... wow! You should have raced her. :-)

Let me know how you make out,
Wes


"C. Bailey" <reply (AT) newsgroup (DOT) com> wrote

Chris,

We has been giving you good advice. My Malibu is also making noises that
sound very much like bearings. I haven't tackled this job on the Malibu
yet, but I just did it on my other GM car, and I'm assuming that the process
is very similar. One of the steps in the installation was to ensure
tightening of the spindle nut to the proper torque value. Failure to do
this could result in premature wear. It's very difficult to get this right
without a torque wrench. It's not a hard job - any shade-tree mechanic
could do it in their driveway.

Steve


"C. Bailey" <reply (AT) newsgroup (DOT) com> wrote

Changing the wheel bearing has proven to be quite the task. I bought one
from Canadian Tire for $172 CND. They also will lend you the socket for the
axle (when you put a deposit on it). The 36 mm fits loosely, but I was able
to get it off with this tool. I removed the bolts that attach the caliper
(were they ever tight!), and I wired this to the spring. I then removed the
rotor. And then I had a bit of a surprise. There are no torx head bolts
looking at me! The hub assembly is held in place by three, hex head bolts
that you must get from the back side. Of course, the CV boot is in the way,
and you can't get a socket or wrench on these bolts squarely. Thus, it
appears to me that the whole thing has to come apart. I had no trouble
removing the two bolts that attach the strut. I had a little difficulty
removing the bolt that attaches the tie-rod. The last piece of the puzzle
is to remove the nut on the ball and knuckles joint immediately below the
strut. The cotter pin and nut are removed, however, I am unable to separate
the ball and knuckle joint. I am told there is a tool for this. Is there a
do-it-yourself way of separating this knuckle? There's almost no way to get
a swing at it, and it is on the suspension arm, so even if I could hit it
from the top, it is sitting on an arm that isn't solid. Am I going about
this the hard way? Any thoughts?

Chris


"Steve Raft" <sraft (AT) cybernex (DOT) net> wrote

According to the Haynes a pickle type ball joint separator will work but
should be used only as a last resort because it will destroy the boot..
I am sure Canadian Tire also rents a ball joint separator. The Alldata
manual suggests you use the correct Gm tool. However I think this is
very expensive- or you could put it back together. The haynes manual
(available on special order from CT for $20) suggest that you can remove
the three bolts from the back by using a a swivel socket and a short
extension without have having to remove the drive axle.

C. Bailey wrote:

I have a bit more information for anyone that wants to try replacing the hub
assembly on a 99 Malibu.

I managed to separate the knuckle joint (the primary pivot for steering), by
using a gooseneck to pry the joint apart, and by hitting it with a hammer
(on the side) at the same time. The hammer was primarily for vibration
effect - it didn't take much of a "rap" to make it part. I also put some
penetrating oil on the joint several hours prior, and I believe this
helped - the joint was fully penetrated when I managed to pry it apart.

Once this was apart, I used a spindle puller (it's part of the loaner tools
you can get at Canadian Tire) to pull the hub off the axle. It didn't take
too much effort to pull it apart with the spindle puller. But I suspect it
may have been a little troublesome without it.

Then I was finally able to remove the hub assembly. I called the bolts "hex
head bolts." This was the incorrect term. They are a standard bolt head.

I was going to put it all together tonight, but the nut from the tie-rod was
a nylock nut, and I want to replace it with a new nut before assembly.

Thank you to the group for all of the help. Hopefully at the end of this
process I will have fixed the hum. If not, I will replace the opposite
wheel bearing.

Chris