Noise From Front End

[Mr_Rich]

I just got a 97 Suburban K1500 and it has what I originally thought was tire noise. This noise is a kinda howling noise that starts at about 35mph increases with road speed but is not affected by engine speed. That is there is no change in pitch as the trans shifts.

 

It seems to be coming from the front end of the truck. When I turn in either direction it does not affect the pitch so I do not think it is the hub bearings.

 

Can anyone give me some suggestions on trouble shooting this issue?

 

I went under the truck last night and everthing looked clean with no evidence of any leaks. The front drive shaft did not seem to have any play, no torn boots on the axle half-shafts, and no excessive play in the half shafts.

 

One thing I did notice driving was that at higher speeds the noise seems to increase when I accelerate and to decrease quite a bit when I coast.

 

Thanks in advance,

Rich

[95Sierra2500]

Check to be sure your front differential is full of fluid. Just because it isn't leaking doesn't mean it's not empty.

 

Does the vehicle tend to pull one way or the other? You could have a brake pad dragging on the rotor just a bit. It would make a somewhat howling noise depending on what type of material the pads are made of.

[Mr_Rich]

I checked diff and transfer case levels and they are ok.

 

I jacked up the front end spun the tires and found the drivers side squeaks at the same spot on each rotation. This noise only happens when I rotate the tire in the direction that it would spin if the truck is moving forward. It seemed to get a little louder if I pushed on the axle shaft.

 

I also noticed that there seems to be a lot of drag when I rotate the tire but I do not know if this is an issue. My old Bronco and IH Scout had straight axles with locking hubs not the IFS the Suburban has.

 

It's hard to localize the sound but I think it is from one of the CV joints on the axle, tomorrow I will get a stethoscope and verify the source of the sound.

 

Thanks for the advice and I'll be sure not to cross post in the future.

 

Thanks again,

Rich

[Mr_Rich]

I got the stethoscope and when I went to check the squeak in the axle the squeak was gone. I could not hear any unusual sounds in the axles or the hubs.

 

I had my daughter drive the vehicle back and forth while I stood on the side of the road and I think the sound may be from the rear end now.

 

Maybe the u-joints of rear diff.

 

Regards,

Rich