Thought I would ask you fine gentlemen your advice on this one. In the last couple of weeks I have noticed a low hum noise from about 30-40 mph that gets a little louder but drowned out then due to the engine noise / speed etc. So at this point not very loud but wasn't there previously. My first thoughts were a wheel bearing / brake dragging etc. I jacked car up and checked for any movement in the rim or noise from the bearing....nothing!. I then removed all the brakes, cleaned, greased were necessary and replaced. Still the noise is apparent. The only other symptom is the front right rotor and hub gets hotter than the rest. Do you think this is the early signs of a bearing failing? Thanks in advance.

 

 

Yes, I know how to determine how the bearings are worn. Rocking the wheel etc and seeing if there is any play. I took the vehicle for a leisurely drive with the intention of braking as little as possible. ( I live in northern Maine and traveled some 12 miles without barely touching the brakes.) On arrival home the front right front rotor and hub was hotter than the rest. There is also definitely a hum. The brakes are not binding and they dont smell 'hot' as they would if they were. I am not sure when the gear oil was done but it had a service in the summer of 2016 prior to my purchasing it.

 

In case you require the new wheelbearing assembly: search for Firstline FBK1329. I replaced my fronts on my DB9 at around 40k miles.

 

 

 

 

If the right front rotor is heating up more than the others, you could have a piston hanging up in the front right caliper. I had similar symptoms in my 87 911. I replaced the calipers to solve the problem,

 

Thanks for the suggestions guys I will take a look into it further this week and report back.

 

How many miles, and had any impacts from curbs or harsh roads. Right fronts seem to get more abuse from rough road conditions.You will not feel movement when checking a cartridge bearing unless the wheel is about to fall off. But with the temp. Increase and noticeably more noise I'd consider the bearing replacement the next step. You have already taken it apart before so it's a fairly easy DIY bolt up installation, get new bolts with the hub assembly.

 

The vehicle has 74k miles and I have only had it two years. I agree the next step is purchase a replacement and give that a try. Thanks for your input guys!

 

Gotta agree with Vantagelvr above - you're not gonna learn much about the bearing with it up on jacks - possibly though if you turn by hand with a hose to your ear or with a stethoscope. This is from my old school days:

Checking for a worn wheel bearing: Try doing tight figure 8's at about 10-15 mph (not at high speed) in an empty parking lot - radio off - windows down. If the bearing is shot you'll hear the droning when you make particular turns one way as the stress is on the opposite side.
Checking for a sticking or seized caliper: A seized caliper should be pretty easy to diagnose. Go for a 15 minute trip (try not to brake too much) and when you return immediately spray water onto the caliper and rotor using a Windex type bottle. Do both sides - you'll know by the sizzle (steam etc.) whether it's not releasing properly while driving.