So I posted a few weeks ago about a humming/growling noise that I couldn't find my life. I thought it was the front passenger wheel bearing. So I changed it. Along with both side CV joints and both side springs and shocks. Sound is still there. So now I'm almost 99% sure its the pass rear bearing. So I'm gonna go ahead and change both. My questions are: 1 are the axles c clip? 2 I ordered 2 timken bearings and 2 seals. Are these the only parts I'll need? 3. What are the gear oil specs for the diff?

 

you would be better off putting the vehicle on jackstands...running it in the air and listening with a stethoscope. Rear wheel bearings on a solid rear axle rarely go bad. I haven't changed one in 10years.
Are you sure its not tire noise from irregularly worn tires? They sound just like a bad bearing?


if you have a 1500 series, the axles are retained by c-clips. you will also need a diff cover gasket and 3Liters of full synthetic gear oil...75w90 is probably the correct viscosity iirc

 

I guess I should've did it that way before I ordered the parts. I'm gonna try it and swap the tire to the other side. I was leaning towards the bearing because when I take a slight left I feel it in the right side. When I go right I don't hear it as much? Its definitely in correspondence with speed. And it develops a vibration felt through the body at around 70 mph. But I don't think its related. Aside from a tire going bad. What else could it be? And what would be the best way to test a tire?

 

the rear axle bearings don't handle lateral thrust loads....just radial loads. turning is not going to change the load on the axle bearings.


tire noise will not change when swaying the vehicle either....


I'd isolate the noise first before changing anything.

 

I don't know what else it could be then. It definitely has a rotational sound to it. Also does it in neutral.

 

tires are easy to rule out for noise...visually inspect the tires for a saw tooth pattern. it will be on the inner or outer most portion of the tread. it occurs from the tire scrubbing from bad toe alignment. It creates a growling noise at speed.

 

Tires look fine visually. I ran my hand across the surface as we'll to see if there are any irregularities. I'm baffled as to what else it could be. I mean what are the chances it is one of the bearings?

 

if you want to change them out go ahead. Without listening to where the noise is loudest with a stethoscope you may be changing out a good part.


the noise may also be front the rear diff. I always run the car on the hoist as I have got burned calling parts from test drives only.


your av isn't a 4 wheel steering unit correct...as the rear bearings are different

 

No 4 wheel steering. I ordered them already so I might as well change them. If I was paying for labor I'd be tight. But the parts are fairly inexpensive. But what in front of the rear diff would cause this. And I was just out driving. Seems as the vibration might be related to the noise.

 

Ok so i just lifted the rear end and ran it with no load. there's definitely a grow coming from the rear end. Not exactly sure exactly where? and its definitely causing a vibration that transfers to the body. and like my initial guess. i think it might be the bearings. it's actually sounds louder on the drivers side. the only other thing i can think of is it could be something in the rear diff? no signs of any fluid leaking though. any thoughts or comments? i'm still waiting on the bearings and have to go away on business. but will occasionally check the site. once i get back i'll swap the bearings and update

btw this truck is not abused in any way. just normal everyday driving. 112k on the clock and does not tow
i did not check diff fluid while i was under it

and just to recap:

rotational growling noise from under the vehicle while driving.
gets louder as car goes faster.
does it in neutral
vibration felt through body of vehicle at higher speeds 60+
gets louder on highway when i take lefts (vibration felt more)
seems to almost disappear when i go right
no slipping or clunking felt
no sign of leak in differential
does not cause drag while coasting