front wheel bearing replacement - got ideas?

[upallnight]

When I installed the new bearings they were put in the freezer overnight, so the bearing would have shrunk a little bit due to expansion/contraction of material due to temp.

When I rebuild an engine for my seadoo jetski or seadoo jet boat I always put the crank in the freezer. It shrinks enough that I can put on the bearings which is heated in the oven to about 200F that I don't need a press to put them on.

[David.X5]

That was a good reminder - I meant to put the thermal data from the calculator - for this combination, cooling the bearing to -85C (-120 F) will make it an exact fit. You won't get there with a normal freezer, but dry ice would get close.. Likewise, you would have to heat the hub to 125 C (250 F) to get to the point where it is an exact fit (still not a sliding or running fit, but better than interference). Some combination of the two approaches would also work.

[upallnight]

Our German Miele oven is rated at 480F so well within the 250F limit, but I don't think Mrs. Upallnight would want me to use the oven to fix cars. LOL

[Perrier]

So I got to doing this job today. Front left bearing.
I was getting this deep hum noise between 50 & 60 km/hr. Turning sharp left turns makes it quiet, so I suspected the bearing.
Now that a new F A G bearing in place, and a test drive, the noise is still there.

What do you guys think may be causing that noise?

[cn90]

@Perrier,

Maybe tire noise...

Diagnosing wheel bearing is very very difficult b/c tire noise (especially when the tire is old) is more common!!!


Unless you do it properly, then misdiagnosis is common:

1. Jack up the wheel and support with jack stand.

2. Remove wheel.

3. One must remove the brake caliper and hang it. Leaving the caliper alone will confuse people b/c the brake pads will cause the scraping noise.

4. Once the caliper is out, you should want to re-install the wheel with lugs (just snug the lugs tight with your hand, not need to overtighten the lugs).
The reason for the wheel is that: spinning the bearing alone is hard. With the wheel installed (but brake caliper out), it is much easier to spin the bearing.

5. Now spin the wheel and listen for noise.

Below is a good video on bearing noise...

https://www.youtube.com/watch?v=Gf3k21QiQxs

[upallnight]

Maybe the wheel bearing on the right side???

[Perrier]

Originally Posted by upallnight

Maybe the wheel bearing on the right side???

Uthat would explain it going quiet when I turn left.

[Perrier]

Originally Posted by Perrier

Uthat would explain it going quiet when I turn left.

Messed up typing. Meant to say
That would not explain going quiet when I turn left. Less weight in the bearing makes it quiet down. No?

[cn90]

Just common sense, when you turn R, the momentum of the car is going forward (basic Physics), it puts stress on the LF bearing. So if the LF bearing is bad, it will complain.

And vice versa...

Another reason to replace bearings in pair, unless you have very low mileage.

[upallnight]

I always thought it was weight transfer when you make turns or brake.