Finding a wheel bearing vibe?

[Glennb]

Hi again guys. As I was getting no where with finding this vibe through the drivetrain area so I thought I'd go back to the wheels as I have found a NEW vibe (Hmmmm) while turning through an S bend I go through at my problem vibe speed (40ks) and only at 40ks (give and take a few ks).

I will start over again in detail and what Ive found about the original vibe.

In 2wd I get this vibe that starts at about 25ks then gets real bad about 35-40ks then decresses and comes back about 80ks.I can make the vibe worse if I ride the brakes.But this vibe is not there when slowing down.

In 4x4 the vibe decreses probably about 80-90% I recon.

But at 40 and 80kph (and a few ks either side of those speeds) the vibe turns into throbbing in the ear vibe ( best I can explain it) and is the same in 2wd and 4x4 and happens while accelerating AND slowing down.

also happens in all gears

THINGS I HAVE DONE
Ive checked all mounts. all ok, the auto has saged about 3mm, but been told buy misu that it shouldnt cause any drama.
The vibe has happen with 2 different transfer cases on it.
Ive had the tail shaft balances and all ok.
Ive lowered car back to stock height and vibe still there
I cannot feel the vibe through the steering wheel or pedles
I have 2 sets of wheels and the vibe is the same with both.



THE NEW HUMMMMING VIBE
I think this vibe may also have something to do with the other vibe because it happens around the same time.
I go through an S bend every day and traveling at 40ks (and will only happen at 40ks or 2-3 ks either side of 40 and also have 2 be in I think 3rd gear and be accelerating)I have found I get this Hummm now when I turn right though it but disapears when the car staightens up (sometimes it will hang around with a softer humm but will go away soon after)
Have gone through it in 4x4 and seems to still do it but quieter (I must check this again though)
It seems to be that it has to be in a higher gear for it to happen.(its an auto and the car is not stuggling either)
When I swerv left then right, the right give the loud humm but the left I will just get a softer humm.

THE WHEELS THEM SELF
They all feel pretty tight. The front left has very small movement and there is probably a touch more play in the CV than the right.(the left a reco)but if the vib was caused by this I would of thought I would feel it through the steering wheel).


So what else can I do to check the wheel bearings?

I think that covers everything.So does it sound like a wheel bearing or something else.

Cheers guys as this is my last hope or its going to cost me big $bikkies$ for trail and error which all the mechanics want to do. The vibe is very anoying and I do need to find out what it is in case it is or may cause some expensive problems.

Cheers
Glenn

[J Top]

Like NJ said, take your drive flanges off and try again.
Front W/Brgs you jack the wheel off the ground and spin the wheel by hand, listerning for rumbles and feeling for vibration through the wishbones. This will be more accurate with the D/Flanges off if you are not used to looking for brg noise.
J Top

[Glennb]

Thanks Jtop, so the drive flanges your talking about are the 4 bolts on the diff ends of the front and rear drive shafts?
But even though this vibe I have will not come in untill around 25kph, should I still feel something when just turning the wheel buy hand?

Cheers
Glenn

[J Top]

The drive flanges are on the end of the axle/CV. Remove the dust cap, remove the circlip, undo the 6 bolts and remove flange. there is now nothing rotating in the front except wheels and bearings. Dirt can get into your bearings with the flanges off so keep them clean, stay off dirt.
25kph is 25000 metres per hour which is about 2.5 revs of your wheel per second.
J Top

[Noisey]

Humming can also be caused by worn steering components or incorrect wheel alignment. Tierod ends when worn allow the wheel to move a small fraction which would give you a vibration.

[Glennb]

Ok, I jacked the car up today and checked all the wheels by pushing, pulling and turning. The back seem fine but both fronts seem to have a little movement. Pushing and pulling from the top back and fowards their is a little movement on both front wheels(but couldnt hear or feel any grinding noise in the bearing when turning it), is this normal or should they be as tight as the rear wheels?? I also did notice when I jacked up the car that the wheels pulled in a bit as they lifted off the ground, is that normal?
But when I put it 4x4 the small movement I have in the front wheels disapears. (and so does the vibe when I drive 4x4)could they be related I wonder.
So, is it normal to have very small movement it the front wheels in 2wd? then have it tightn up when put in 4x4.
Cheers
Glenn