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Bearing noise? 2009 S/T 2WD

1K views 5 replies 2 participants last post by  J_C 
#1 ·
2009 4.6l 2wd Sport Trac. I just put on new tires (BFG A/T) and changed front D/S bearing assembly. There was play and noise, so it was needed, but I'm still getting that one-sided hum. Steady low noise going straight, gets louder when I cut to the right, goes away when I cut to the left.

Have not had a chance to do a physical inspection of the read end, and not sure I'll know what I'm looking at. A lot of new stuff to me. (Newest truck I've previously owned was a '98 Dodge Ram 1500. I need to get my Chiltons or Haynes or something.)

Also recently changed both tie-rod ends, sway bar linkages, passenger side upper control arm bushings (planning on doing the other three sets next oil change). Wondering if there's excessive wear on those the D/S control arm bushings that I didn't detect, might that cause this to happen? Other than that, front ends seems to be in good shape.

Any thoughts or advice on something I should be looking for. Maybe something in the rear end? If the front D/S bearing is new, then what else could be causing this hum. I don't think it's tire noise as it's only on one side.
 
#2 · (Edited)
I agree that it seems like bearing noise on the front passenger side.

Bushings would not cause this, but it is curious to me that you replaced the bushings instead of the entire control arm because usually the ball joints go out before the bushings, and as far as I know, the BJ's are built into the upper control arm (not separately replaceable, maybe Moog has an aftermarket control arm that allows it) so replacing the whole arm would give you new BJ and new bushings. Edit: I may be wrong, I thought they were built in but I'm seeing upper BJ's sold separately which would only make sense if they're replaceable separately, though on some model years you have to buy the aftermarket control arm that allows this.

However a BJ wouldn't cause the humming either. I'd also inspect the tires, as a bad BJ or bushings could cause uneven tire wear and that could cause humming. I'd rotate the tires to see if the hum follows a tire.

Did the noise start immediately after the tires were put on? Is it possible some tire monkey used an air impact wrench till it couldn't go any further and grossly over-torqued the lug nuts? Maybe it's just that one of the tires is defective?

I assume you had an alignment done after replacing the tires, or at least after replacing the tie rod ends (and again after the upper control arm bushings if they weren't both done at the same time) and knew it was still good when the new tires went on?
 
#3 ·
Thanks for the thoughtful reply. My response ...

I agree that it seems like bearing noise on the front passenger side.

Bushings would not cause this, but it is curious to me that you replaced the bushings instead of the entire control arm because usually the ball joints go out before the bushings, and as far as I know, the BJ's are built into the upper control arm (not separately replaceable, maybe Moog has an aftermarket control arm that allows it) so replacing the whole arm would give you new BJ and new bushings. Edit: I may be wrong, I thought they were built in but I'm seeing upper BJ's sold separately which would only make sense if they're replaceable separately, though on some model years you have to buy the aftermarket control arm that allows this.
Actually had it done at a shop and didn't watch the whole process, but these guys are good and have never jerked me around. I did see that the bushings had been replaced.

However a BJ wouldn't cause the humming either. I'd also inspect the tires, as a bad BJ or bushings could cause uneven tire wear and that could cause humming. I'd rotate the tires to see if the hum follows a tire.

Did the noise start immediately after the tires were put on? Is it possible some tire monkey used an air impact wrench till it couldn't go any further and grossly over-torqued the lug nuts? Maybe it's just that one of the tires is defective?
The hum was happening before I got the new tires. I had hoped that it was just tire noise with the old, worn tires (they just barely had legal tread on them). When they raised the truck up to put on the new tires, there was play on the front D/S wheel, so we swapped that bearing assembly out then, as well.

I did think about a defective new tire being the issue. Maybe I'll have them rotate out the tires side to side. The shop is pretty accommodating and I've given them a fair amount of business lately.

I assume you had an alignment done after replacing the tires, or at least after replacing the tie rod ends (and again after the upper control arm bushings if they weren't both done at the same time) and knew it was still good when the new tires went on?
Yeah, alignment after the all of that (tires, tie rod ends, sway bar terminals, bushings, etc.) were done. Truck tracks well.

My main concern is if it might be bearings or drive train components on the rear end. I wouldn't think that drive train components would cause that kind of one-sided hum, but I'm guessing that bearings on the real wheel might would.
 
#4 ·
I can't imagine it would be drivetrain with it changing when you change lanes. Your rear appears to have serviceable bearings, instead of replacing an entire hub assembly.

If you don't need to be going fast, how about having a helper in back with the lift gate open, trying to figure out if it's in the rear and which side? I've also heard of people duct-taping an old phone near questionable areas to record noises and compare the volume of the recordings to locate it, but never tried it myself.

Then again, if one of your front bearings was shot, and the passenger side was traveling the same roads, odds are it is due for replacement too. The other possibility I can think of is that the axle nut wasn't torqued properly on the replaced driver's side front bearing, as improper torque can wear them out fast, or it was just defective from the factory.
 
#5 ·
Yeah, that's what I thought, too, about the drive train. Didn't make sense that the noise would change with the weight shift.

The front end, it's a sealed bearing assembly, the whole package just bolts to the plate that's connected to the control arms. I checked the bearings first when I got home (had the swap done at a shop), but was shocked to see that there's nothing to tighten, no spindle. Just a sealed package. Never saw anything like that before. (Like I said, newest truck I've owned up to this point has been a '98 Dodge.) So, unless it's a bad assembly, not the front end.

I'm leaning heavy on rear D/S wheel bearings. I may try te phone thing, but it'll have to wait until next week as we're gone all this weekend (not with the truck).

Thanks.

I like the idea of taping an old phone to the truck to record noise. May try that! I have a couple that I could use.
 
#6 ·
Oops, I didn't notice or forgot that you only have 2WD so yeah, no axle nuts on the hubs in front, because no axles there!
 
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