06' AWD howl.. rear diff or wheel bearing?

[MikeInMaine]

Hi folks,

Need some advice diagnosing a "howl" that gets really noticeable above 40mph, Once it starts, you can hear it while slowing down till about 15mph.

Coasting in neutral over 40mph and the howl doesn't change pitch or volume.

Pretty sure its coming from back of car.. possibly passenger side.. not sure. Pretty sure its not the front passenger bearing as I did that one a little while ago and was very careful not to mess it up when pressing it in.

Jacking up the vehicle and rotating all the wheels reveals no noises or rumbles.

When negotiating curves at high speed, the howl stops on a right curve and stays the same on a left curve. As soon as I hit a straight after a right curve, the howl is back. From this I am concluding that its the passenger rear wheel bearing.

However, rear differential fluid was low. Could the howl instead be the rear differential?

I started to take the passenger rear suspension apart but could not get the lower support camber bolt out without destroying the rubber bushing in the knuckle. I was hoping to pull the passenger rear hub and bearing and test it for noise/feel.. but have to call the dealer first to make sure I can get the rubber bushing and bolt.

Any advice on whether this is likely to be wheel bearing or differential noise is appreciated!

Mike in Maine.
2006 Matrix XR AWD

[bluneon]

safely raise the vehicle, start the engine and place in drive. allow all 4 wheels to spin. take mechanics stethoscope and probe all knuckles. the one loudest is going bad.

[sideshowalan]

I agree that it's a passenger side wheel bearing. When you turn right it puts the weight on the drivers side which would quiet a bad passenger side bearing.

Determining front or back is a little trickier though. Best thing is to have someone else on the passenger side with the window down that can tell you for sure if it's front or back. A lot of people on here say it's very difficult to install new front bearings correctly.

[MikeInMaine]

It is difficult. I've done the front passenger side already. If you have a press you can use the outer race from the old bearing and cut a round steel disk as a push plate to go inside it, to press the new bearing in without putting any force on the inner race. So I'm pretty sure its the rear passenger side howling now.

My problem is how to get the darn lower camber bolt out (part of the knuckle support) without destroying the knuckle bushing.

Mike

I agree that it's a passenger side wheel bearing. When you turn right it puts the weight on the drivers side which would quiet a bad passenger side bearing.

Determining front or back is a little trickier though. Best thing is to have someone else on the passenger side with the window down that can tell you for sure if it's front or back. A lot of people on here say it's very difficult to install new front bearings correctly.

[ehoff121]

However, rear differential fluid was low. Could the howl instead be the rear differential?

Did you top off or change the fluid?

[MikeInMaine]

I changed it about a year ago.. about 15000 miles ago.. so in this case I just topped it off.

However, rear differential fluid was low. Could the howl instead be the rear differential?

Did you top off or change the fluid?

[sideshowalan]

My problem is how to get the darn lower camber bolt out (part of the knuckle support) without destroying the knuckle bushing.

You don't need to remove the whole knuckle, the rear bearing is not servicable and is replaced as part of the hub. The hub is only held on to the knuckle with 3 or 4 bolts. You may need a hub puller to free it.

[SeattleJeremy]

My problem is how to get the darn lower camber bolt out (part of the knuckle support) without destroying the knuckle bushing.

You don't need to remove the whole knuckle, the rear bearing is not servicable and is replaced as part of the hub. The hub is only held on to the knuckle with 3 or 4 bolts. You may need a hub puller to free it.

The bearing is held on by four bolts. Here's a picture of the rear AWD bearing, the FWD ones have a piece of plastic over the middle.

[MikeInMaine]

Don't I have to remove the knuckle mounting bolts to get the room to extract the axle from the hub.. even if I remove the 4 hub bolts first?

My problem is how to get the darn lower camber bolt out (part of the knuckle support) without destroying the knuckle bushing.

You don't need to remove the whole knuckle, the rear bearing is not servicable and is replaced as part of the hub. The hub is only held on to the knuckle with 3 or 4 bolts. You may need a hub puller to free it.

The bearing is held on by four bolts. Here's a picture of the rear AWD bearing, the FWD ones have a piece of plastic over the middle.

[SeattleJeremy]

Don't I have to remove the knuckle mounting bolts to get the room to extract the axle from the hub.. even if I remove the 4 hub bolts first?

Not having done this my self, I'm only guessing here, but it looks like you'll need to remove the axle nut, but the axle should be able to stay in place.

[SeattleJeremy]

Attached is the repair procedure for the AWD rear wheel bearing.

Make note of the diamond shape that denoted non-reusable parts like the axle nut.

[MikeInMaine]

That's VERY helpful. Its step 12. b. that I'm stuck on. Cannot get the camber adjustment bolt out after removing the nut and adjuster. Seems frozen inside the bushing that's inside the knuckle assembly itself. If I destroy the bushing, looks like I will need a whole new knuckle at $145. Any ideas for getting this bolt out?

Attached is the repair procedure for the AWD rear wheel bearing.

Make note of the diamond shape that denoted non-reusable parts like the axle nut.

[SeattleJeremy]

Here are some more pictures of the area, with (NM, Ft/lbs) for each bolt, when putting it back together.

Does it turn/move at all? Have you tried WD-40 or Liquid Wrench to loosen it? Rubber mallet?

[MikeInMaine]

yes, I can turn it about 1/4 turn either way, then it locks up. I tried driving it out by putting the nut on backwards and beating on it. That just bends the mounting tabs on the support. tried pblaster. I think the bolt has become one with the metal sleeve inside the bushing.

Here are some more pictures of the area, with (NM, Ft/lbs) for each bolt, when putting it back together.

Does it turn/move at all? Have you tried WD-40 or Liquid Wrench to loosen it? Rubber mallet?

[MikeInMaine]

aha.. I'm NOT the first..

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I was afraid that cutting and then driving out the remains of the bolts was the best strategy... thanks all for advice.

[bluneon]

has this vehicle been properly diagnosed and repaired?

[Nasmfell]

has this vehicle been properly diagnosed and repaired?

OP probably sold it.

[MikeInMaine]

Sorry, didn't see the question.

Yes, the howl was the rear wheel bearing. Since I was also doing the leaky rear diff seals, I had to cut both knuckles out of the car. I did the bearings on both sides.. figured this way I might not have to go back into these assemblies before I'm done with the car. The best price on new knuckles was somewhere out west. in AZ I think. Got her aligned after it was all back together and she's like a new car.