Which Wheel Bearing Is Failing?

[Wendelspanswick]

I've got a new to me Ford Ranger Supercab 4x4 pickup (08 plate) and its got a rumbling noise.
The noise appears at about 20mph and stays till about 60mph.
The rhythm increases with road speed and not rpm, changing gear has no effect nor does dipping the clutch or changing from 2wd to 4wd.
This makes me suspect either the final drive or wheel bearings.
Hard left handers seem to increase the noise slightly but not by much so this makes me suspect either the front or rear right hand side wheel bearings.
Any other tricks to try and narrow the culprit down.
I've ordered a cheap stethoscope and I'm planning on blocking up the axles and running the car to pick up the vibrations with it but I'm not sure if the noise will be detectable with no loading on the road wheels.

 

[CompoSimmonite]

Find an empty carpark and drive around in circles. If it's happening on hard left lock then it could be a CV joint in the front axle.

 

[Ruffian]

If it''s sounding that bad,
Just jack it up and shake the wheel top and bottom and should be able to figure out which one is shot

 

[daedalusminos]

Does it change underload Vs overrun?

 

[Richard.]

Jack em up and check for play. It might have some on the suspect bearing.

 

[Wendelspanswick]

Find an empty carpark and drive around in circles. If it's happening on hard left lock then it could be a CV joint in the front axle.

It's not a CV joint as it it has free wheeling hubs and it makes the noise in 2wd (rear wheels only).

 

[Wendelspanswick]

Jack em up and check for play. It might have some on the suspect bearing.

I've never found that to work until the wheel bearing has failed completely and I don't want this one to get that bad if I can help it.

 

[Wendelspanswick]

Does it change underload Vs overrun?

No it stays constant.

 

[Cobbler]

Could it be tyre noise?

 

[Johnseat]

Multitude of possibilities.

Any of the wheel bearings.
Prop shafts and their bearings.
CV joints.
Tyre tread patterns and uneven wear.
Diff.
Gearbox output bearings.

At work I'd be putting it on a two poster ramp and getting someone to drive it suspended in the air whilst I had a walk around listening.

 

[armalites]

I've just been through similar on a 2010 Volvo V70.

It had gone from quiet and no road noise to a hum/drone. I bought two new bearings of a decent brand. Had it on the ramp and there was absolutely no play in either bearing. Rotating the wheel there wasn't anything noticeable but there is a bit of drag so it's difficult to tell. I've had mishaped tyres give similar noise before but they looked ok. I replaced the left one as that seem to be where the most of the hum was coming from. Once I had the drive shaft out it was clean there was a bit of noise from the bearing so I was quite pleased. Got it all back together and it was better but still noisy. Had to use it like that for a few days and managed to dig the other one out one evening and it was way worse than the other. Once back together the car was transformed, wife had taken it in longish run to visit family in the last few days and the average mpg jumped by 5mpg and that was without resetting so the net result is more than that. The bearings I took out were clearly not the originals and had some mickey mouse name on them. I put FAG bearings in.

On one of previous Volvos an 850 there was absolutely no noise and the car drove fine but when fitting some tyres found the wheel could be rocked quite badly.

If the bearings are too much and it's done a few miles I would just replace them to rule it out.

Weirdly looking at the pictures on ebay some showed taper bearings some show sealed ones for Rangers

 

[Kayos]

Mine was noisy turning left, was right front wheel bearing (drivers side)

I’m guessing it got noisy as the wheel unloaded turning left

 

[Rudi McAnichal]

Had similar noises on a 2004 Grand Vitara – almost like a wheel bearing, but not much affected by cornering in either direction. Suzuki mechanic drove it for 2 minutes and said well-known problem, caused by wear in the front diff, changing the diff oil will sometimes reduce the noise, but probably needs a new diff. He was right, and it cost the best part of £1k to cure. It seems that oil in both front and rear diffs on that model was supposed to be replaced after the first few thousand miles, but some main dealers didn’t bother, and the problem hardly ever became apparent until after the warranty had expired.
Hope the OP's Ranger does not suffer from the same affliction.

 

[bricol]

Just had similar on an Alfa Romeo 159 Q4. My worry was the power take off box made by ZF Alfa used to get power to the rear wheels from the gearbox - the bearings on the output pinon to the rear failed a couple of years ago and it sounded just like a wheel bearing had gone.

Lifting it on a ramp with all wheels in the air and sticking it in gear with the engine running it made it obvious as the shaft was rumbling badly (crap design - collapsible spacer between the outer taper roller and a small shoulder on the shaft - the spacer over 80.000 miles had crept over the shoulder, backing off the pre-load. Afraid I repeated it as by the time I've done another 80000 miles, I won't be able to avoid fuel for it!).

This time did the same trick and thought I could hear more noise from the front offside wheel - carefully jamming the front wheels one after other (not both!) allowed the other to speed up (via the dff of course) and the noise increased on the offside.

No noticeable difference in noise on the road on left or right hand turns, and no play. When I changed the bearing, the old one was noticeably dry and stiff, but no play.

 

[Wendelspanswick]

I see you can buy electronic stethoscopes, basically a cordless microphone that you attach to the suspect bearing housing and monitor remotely but at £80 it's a bit too pricey.
My experience tells me it's a wheel bearing but it's determining which one.

 

[Wendelspanswick]

Mine was noisy turning left, was right front wheel bearing (drivers side)

I’m guessing it got noisy as the wheel unloaded turning left

Surely the right wheel would load up when turning left which is what you would expect?

 

[galooph]

Have you got an IR thermometer? I've seen those used to check wheel bearings on trains, the idea being that a rough bearing has more friction and generates more heat.

 

[Kayos]

Surely the right wheel would load up when turning left which is what you would expect?

As you turn left the weight transfers to the left side so the right wheel can move about more, hence making the noise

It did actually get far far worse and I ended up getting recovered home

 

[daedalusminos]

If it's got free-wheeling hubs you might be able to hear just by spinning the wheel

 

[armalites]

As you turn left the weight transfers to the left side so the right wheel can move about more, hence making the noise

It did actually get far far worse and I ended up getting recovered home

When you turn left the load transfers to the right and the as you are turning left the right hand wheel will be rotating faster than the left