[SOLVED] Front (4wd) Axle Spewing Grease - Also Scraping Sound

[EddieC]

I just started hearing a light metallic metal on metal grinding noise near the drivers front wheel on our '08 4wd Tahoe.
It is a sound reminiscent of a pebble caught between the the brake rotor and backing plate on other vehicles.
The noise is most noticeable when applying the throttle, both from a start and when rolling.
Jacked it up and rotated the wheel and I hear nothing odd but crawling under I see grease spewed around where the steel axle enters a rubber boot near the outer end, on the edge of the boot away from the hub.

Any thoughts on that?

Should the truck be laid up even if 4 wd is not being used?
Can the assembly be pulled out without removing the hub and related brake parts?

 

[Fless]

Sounds like the CV (half shaft), which can be replaced without removing the hub & brakes. Pic?

If it's the half shaft, see video below.

How to Replace Front CV Axle 2007-17 Chevy Silverado

Check out this video to learn how to replace a broken or bent front axle on your 07-17 Chevy Silverado. The part is available here at 1AAuto.com!

www.1aauto.com

 

[EddieC]

Sounds like the CV (half shaft), which can be replaced without removing the hub & brakes. Pic?

If it's the half shaft, see video below.

How to Replace Front CV Axle 2007-17 Chevy Silverado

Check out this video to learn how to replace a broken or bent front axle on your 07-17 Chevy Silverado. The part is available here at 1AAuto.com!

www.1aauto.com

Only have poor pictures. Yes, the CV shaft at the outer end. Grease is on parts above and below but that doesn't show in the pictures.

Would make a scraping sound even if not in 4wd?

 

[Fless]

They're turning when the front wheels turn, so they could be making noise any time.

That's a problem, but it might not be THE problem. You might want to put the front up on jackstands, in 2wd, and turn each wheel by hand while watching and listening to find the sound. Also check the fluid level in the differential. The scraping could also be a brake issue.

 

[Doubeleive]

you can replace it without to much trouble, you have to break that axle bolt loose (wheels on the ground), then jack it up by the frame so the front suspension is fully dropped, then finish removing the outer axle bolt, then you have around 8 bolts on the other end. once all the bolts are out you can wiggle and finagle it out, replacement is the reverse process, get it in there, then put those 8 bolts back in then the axle bolt, put it on the ground finish tightening the axle bolt.
that might not be your noise source though unless a majority of the grease is already gone, doesn't look that bad from the photos
if you have trouble getting the axle out you can use a separate jack under the spindle to lift the suspension a hair to help get it loose

 

[89Suburban]

I could be wrong but I swore I had to unbolt either the strut or the sway bar link to get clearance to remove the half shaft.

 

[EddieC]

The picture is bad because it doesn't show the accumulated grease on upper and lower suspension members (left axle); piles of grease like it's been thrown in gobs. On closer inspection the boots on the axles on both sides of the truck have the boots torn to some degree where they are clipped to the steel axle but the driver's side is the gusher.

I can not induce lateral movement in the axle at the joint but I can move it in and out along it's length enough to feel and hear.

BUT Fless made a good point regarding "THE" problem.
The noise is not there running in the driveway in park or neutral. It is predominantly after shifting into drive and starting to move and also when going back on the throttle if coasting. Backing up not so much but transitioning to forward brings it out.

I can't seem to post a video to share the noise but am looking for a work around.

 

[Fless]

You'll need to use a site like YouTube to upload your video, then post the link to it here.

 

[EddieC]

Here we go: https://ln5.sync.com/dl/e996a22c0#rvhgkte8-awryquxn-cwqxsp9c-h4ay8dmx

And a little less aggressive take off: https://ln5.sync.com/dl/557f3f920#7du7wdhp-beica9zj-jznq544m-yjdxpjx4

 

[Fless]

Sounds to me like a rock stuck between the rotor and the backing plate, or a bent backing plate with the rotor scraping on it.

 

[EddieC]

Sounds to me like a rock stuck between the rotor and the backing plate, or a bent backing plate with the rotor scraping on it.

That was my thought having that happened repeatedly on the Forester but I jacked the Tahoe up twice and spun the wheel and there wasn't even a faint scratching.
On the ground, it's primarily going forward, not reverse.
I'll be embarrassed if it's the opposite wheel though! Tomorrow is another day.

 

[EddieC]

Fless, back on the axles, what are your thoughts on replacing the failed boots?

 

[Fless]

Fless, back on the axles, what are your thoughts on replacing the failed boots?

I've never had to. Some members here just do the boots; others replace the whole CV axle. Kind of a mixed bag of approaches.

EDIT Here's a little info about CV boots

What did you do to your NBS GMT800 Tahoe/Yukon Today?

04 l59.

www.tahoeyukonforum.com

 

[Doubeleive]

to me that does not sound like a cv axle it sounds more like u joints or driveshaft

 

[EddieC]

to me that does not sound like a cv axle it sounds more like u joints or driveshaft

Thanks for that.
The sound is only in gear and not rolling in neutral.
More snooping around in order when the weather gets off of the roller coaster.

 

[Doubeleive]

Thanks for that.
The sound is only in gear and not rolling in neutral.
More snooping around in order when the weather gets off of the roller coaster.

Chock the front wheels, jack up the rear end, start it put it in gear and listen

 

[Doubeleive]

Or take video with your phone move it around and see if the phone mic can pinpoint the noise

 

[mikez71]

Starter?

Accelerating pulls the starter gear back into flexplate..

Should be worse going uphill, better downhill. Might suddenly stop if you slam on the brakes..

Seems like I call starter everytime there's a noise, so grain of salt...

 

[mikez71]

Maybe cracked flexplate.. video sounds similar at 35second mark..

another one, though these videos seem more constant than yours...

 

[mikez71]

Pretty sure you can remove axles and run 2WD no issue.

Some reports that the hubs can fail easier, but I don't really believe it looking at 2 different brands of hubs (SKF and Timken).
Unless the axle stub keeps the axle sleeve/bearing race from deforming, it doesn't clamp separate pieces together...

(BUT there may be changes in hub design over the years, so definately take a good look at it before deciding)