Front Wheel Hum

[bayaz]

Hi gang,

Lately I’ve been getting some weird humming noise in my front passenger wheel. Generally at highway speeds. Moreover, on sharp turns at slow speeds I’m getting a sound as if the front end skips over something (kind of like when driving over ribbed lane divider). Further, on the same passenger front side, I occasionally hear metal on metal noise when going over potholes, speed bumps and beat up roads (which we have plenty of in CA).

Took off hub assembly to check the wheel bearing and it was like new, so it’s not a wheel bearing. The truck has stiff springs up front to compensate for a heavy bumper (3in lift), SPC UCAs. My alignment doesn’t stay put. Have extra wear on the insides of my 33” bfgs.

Some people say it could be front diff needle bearing, but I’m not sure how to diagnose and it doesn’t explain other sounds.

Let me know if anything I’m missing or should look into.

Thanks!

 

[fkheath]

Hi gang,

Lately I’ve been getting some weird humming noise in my front passenger wheel. Generally at highway speeds. Moreover, on sharp turns at slow speeds I’m getting a sound as if the front end skips over something (kind of like when driving over ribbed lane divider). Further, on the same passenger front side, I occasionally hear metal on metal noise when going over potholes, speed bumps and beat up roads (which we have plenty of in CA).

Took off hub assembly to check the wheel bearing and it was like new, so it’s not a wheel bearing. The truck has stiff springs up front to compensate for a heavy bumper (3in lift), SPC UCAs. My alignment doesn’t stay put. Have extra wear on the insides of my 33” bfgs.

Some people say it could be front diff needle bearing, but I’m not sure how to diagnose and it doesn’t explain other sounds.

Let me know if anything I’m missing or should look into.

Thanks!

Look at T-SB-0012-19 diagnosing the needle bearing issue. One of the main ways to tell if you have it, the sound will go away in 4WD mode.

 

[bayaz]

Look at T-SB-0012-19 diagnosing the needle bearing issue. One of the main ways to tell if you have it, the sound will go away in 4WD mode.

Thanks, I’ll take a look. It’s a bit difficult to test because it’s not loud enough where I hear it as a driver. But it’s definitely noticeable when you’re a passenger.

 

[bayaz]

Reporting back here. Tried going into 4wd and it does nothing to the front end noise. Still sounds & feels like I’m going over a corrugated road when on clean pavement. I keep wondering if it could be lower control arm bushings? I have a ton of play in them.

 

[Ph03n1x24]

Reporting back here. Tried going into 4wd and it does nothing to the front end noise. Still sounds & feels like I’m going over a corrugated road when on clean pavement. I keep wondering if it could be lower control arm bushings? I have a ton of play in them.

I'm no rocket scientist but a suspension issue will cause uneven tire wear which could explain the hum, i.e. cupped or chopped tires as key indicators. Rotating the fronts to the back might eliminate the hum for a time. If you are getting a lot of free play in your steering it's time to seriously consider replacing those worn out parts up front before it becomes a safety concern.

 

[Jivewalker]

Front wheel bearing maybe. With wheel off ground, spin it and place your hand on the spring. If you feel vibration in the spring you need a new bearing. Not to bad of a job to do yourself if you have a pre-pressed assembly. Done it twice on mine. Edit to say I know you looked at the hub for play, but would still check by methos I listed. Had same symptoms.

 

[CutthroatSlam]

Reporting back here. Tried going into 4wd and it does nothing to the front end noise. Still sounds & feels like I’m going over a corrugated road when on clean pavement. I keep wondering if it could be lower control arm bushings? I have a ton of play in them.

Why haven’t you addressed the LCA bushings? You will get wheel hop and feathered tire wear that will result in the hum you’ve described.

 

[bayaz]

Why haven’t you addressed the LCA bushings? You will get wheel hop and feathered tire wear that will result in the hum you’ve described.

Thank you for confirming it. I’ve asked people before and was told that 4Runners naturally have a lot of play in bushings. I tested bushings by putting a pry bar in and was able to get at least an inch of wiggle.

Any further recommendations on testing it? Replacing the LCA bushings is a lot of work.

 

[bayaz]

So I just put a Jack under each LCA and lifted to the point each front wheel was spinning. Looks like the play I get comes from SPC UCAs. Both upper ball joints are shot - one to the point it’s metal on metal clunk, which is crazy because I replaced one of them half a year ago. Further, 3 out of 4 x-axis bushings have play in them. I don’t even have 2 years on the SPCs. Meanwhile I wasn’t able to get any play out of the LCAs in this condition. Wheel bearings are fine too.