Need help on my Silverado.. Grinding.. Whirring sound up front in 4WD

All-
Hey.. Since I know a lot of you are far more mechanically inclined than I am.. Wanted to throw this out there. Recently, I've noticed a pretty pronounced Grinding, Whirring sound coming from the front end of my Silverado when in 4WD. I only engage the 4WD when on snow/ice pack or rain.

Recently these things have all been changed:
Brand New Hub Assemblies in Front
New Calipers up Front
New Brake Pads up front.

It seems the sound is coming from my driver front at the moment, but I've also heard it previously on the Passenger Front as well.
I was hoping the hub change would have fixed it- but no luck. Today riding down the road it sounded horrible.

Any advice?
Thanks!!

Grinding could be the differential. Could be u joints too. If you put it in 4wd and when you take off you hear like clicks or snaps that could mean the gears in the differential are ate up. Whiring noise tho could be u joints. Grease the u joint and then check your differential fluid.

Since it only does it in 4wd narrow it down to your 4wd components. Check them and then just use process of elimination.

More than likely the CV Joint gone bad.....not that you'll replace it yourself, but this describes it quite explicitly.

YouTube Flick

Cv joint is when you make turns. Turn right and if your hear the click it means the left one is bad. And vise versa.

Quote:

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Originally Posted by Yunkman

More than likely the CV Joint gone bad.....not that you'll replace it yourself, but this describes it quite explicitly.

YouTube Flick

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Yeah if im not mistaken your chev has an independent front suspension. My truck has a solid axle. Mine has u joints, yours will have CV shafts. CV shafts will snap and pop amd make grinding sounds. But id definately get it checked out by a mechanic asap. Its real tough to diagnose things like this when you cant see em.

Quote:

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Originally Posted by Bryson

Cv joint is when you make turns. Turn right and if your hear the click it means the left one is bad. And vise versa.

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Just goin thru my notes from school last month, you are correct that they will make noise on turns, but they can also make noise and vibrate going in a straight line. Noisy Usually on acceleration. Although it would be louder and more noticable when turning.

Also check the pinion bearing. Look for leaks at the pinion seal. We just replaced a front diff from a 2003 chev, make sure the 4x4 actuator is fully engaging. This one we replaced wasnt and the fluid was full of chunks of alum. (If its electronic 4wd)

Drive backwards & turn hard (use a car park) left or right, thats when the CV's really make a noise.

bearings also make more noise in turns, but so does bad rubber on worn tires
I'd suggest checking out a Chevy truck 4X4 forum for clues/answers

You can also put it up on jackstands and let it idle in gear, walk around it listening for the sounds, just don't get under it or be in its way if a jackstand lets loose

My guess from the sounds of it, would be a bearing within the front differential.
On the basis that I'm asuming that it is IFS and that you mention that the sounds are in 4wd, ...and not in 2WD, ...here I am asuming this as well.
I had to have a bearing replaced in the front diff. of my '03 Sierra a few years back, ...had a nasty whirring/groan sound while in 4wd and sounded normal in 2wd.
I doubt it's the CV shafts, if the noise changes from 2wd to 4wd as they are always spinning anyway

just a guess here but probably something in the front differential I doubt it is the cv joints since on a Silverado they turn all the time but there is no torque on them in 2wd it could possibly be in the front drive shaft or in the transfer case but you would probably hear/feel that under your feet more then from the front end. if you can get all 4 wheel off the ground and get someone to put it in 4wd and accelerate you can use a mechanics stethoscope and listen to the components and narrow it down

of course if you have a chevy built before 1988 you have a solid front axle and you could have axle bearings or wheel ujoints going out

Thanks guys for all your replies. Here are a few answers to questions. Maybe this helps you help me possibly?

2000 Silverado
As Soon as I push button into Auto 4wd or 4WD High. I get the sound as soon as I start moving as well as going down the road.
It is Only in 4wd, not hearing a sound or feeling anything in 2WD.

Any other questions. Please feel free to ask.. I don't want to tear up the truck.. but with the weather outside- I'm in my 4wd all the time.

I'd look towards the gearbox, have you checked the fluids in it? Might be a good time to change it. Let the first quart go into a clear plastic qt jar or something, then comb through it for metal bits, maybe just let it settle then pour it off the top till you get down to the bottom so you can know if anythings breaking loose. Also poke your finger up on there if possible to check for anything loose that didn't come out with the oil.
After that I'd look on downstream till you find it

Also wanted to add: No Click or Pop in turning. This whirring and grinding is straight down the road, wheel straight- you still get the whirring and grinding if going into a turn.. but no "popping" or "Clicking" if I am turning the wheels.

So As I said.. I'm really not too mechanically inclined.. where do you check the differential fluid? I've never seen like a "dipstick" under the hood for it. Should I be looking for a transfer case "plug" like an oil plug under the truck? If I do find said plug and drain it- where do I add in new fluid. You all are getting to see the "super green" side of me.

Ok.. Did a quick search. Will look into this:
https://www.youtube.com/watch?v=yzBiqB_zqhY

Quote:

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Originally Posted by Jvcr1

My guess from the sounds of it, would be a bearing within the front differential.
On the basis that I'm asuming that it is IFS and that you mention that the sounds are in 4wd, ...and not in 2WD, ...here I am asuming this as well.
I had to have a bearing replaced in the front diff. of my '03 Sierra a few years back, ...had a nasty whirring/groan sound while in 4wd and sounded normal in 2wd.
I doubt it's the CV shafts, if the noise changes from 2wd to 4wd as they are always spinning anyway

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Sounds right from here (NZ) a floating shaft with a bad bearing won't make much noise, but put pressure on it & the shaft will go out of centre & nek minute theres a % of your HP going into spreading two of the ball bearings apart & sideways pressure on the bearing housing & cage.
Maybe the squealings from a ripped up bearing cage? Or the gears grinding at each other.

I know from practice that if a wheel bearings starting to go bad, do a looooonnnngggg turn to the right, or left, while travelling strait. That puts pressure on the bearings & makes them louder.
Also, running the bad bearings wheel on a continous painted line on the road will quieten it down a bit. Painted road is smoother.

So is the consensus that I have a bad bearing within the front differential?
Does that mean the front differential will have to be dropped and torn apart?

The front differential is sorta like a rear diff. There's a fill plug on it somewhere. With a rear diff you just pop the cover off to drain, but the front ones I'm not sure how alike they are(mine has to be pulled, or you can use a pump to pull the oil out thru the fill hole)

The transfer case should have a drain, and a fill plug.
Do you have a repair manual for that vehicle ?

Let a local shade tree mechanic, a friend or neighbor with some mechanical abilities help you detect the problem. Hope it doesn't happen to you like it did to me.....my GMC kept acting up until it died on the road, but then nobody could find the problem and still haven't. It's still dead. Whatever it is will get worse until it ruins something else like a rear or frontend housing, transfer case or wherever the problem exists and then you'll be walking.

You've already changed the hubs and that should have included new wheel bearings in the front if they did it right. That should eliminate that source and leave you to suspect the front differential, the CV joint shafts or the transfer case itself (doubtful on that). A lift on a hoist and inspection should help to pinpoint the problem. I had a 99 GMC halfton 4x4 with a growl that we never did detect. Traded it off. Let us know the outcome.

Update:
Now getting some of this WHIRRING in 2wd.. very very sporadically but would REALLY like to get this figured out. Thanks for all of your help thus far gents!

could still be in the front differential, the halfshafts always spin since they dont unlock from the hubs.

Well sad update today.
Been up under the truck.. nothing leaking.. nothing visible. I had to run out into the jobsite today to get a floor scraper, came back and noticed when I was loading up my tools something on the ground.. some type of fluid. She has started to leak- past the CV joint- at the differential. So the seal has finally worn out. The grinding whirring may be a bearing on the pinion bearing or hogs head.. So for all the labor and time to tear a differential apart and rebuild it- I'm looking to get a used one tomorrow- whole differential.. ****!

That sucks. On the brightside, you now know what the problem is.

An where the heck you been? A day without Fudge is like a day without the cooler. ;)

Sirscrapalot - Free the Fudge!~

I know I have been noticeably absent. I've got a MAJOR project I am in the throws of at my jobsite, and I have also been tearing out the stairwell walls and ceiling at my house. Been working non-stop for the past 2+ weeks. Not much forum time sadly!

Man, Sledge, get your priorities right! ;)

Good luck with the job man, an get your truck fixed. We'll all still be here when things calm down for ya.

Sirscrapalot - I'm like a fine scotch, better with age.

Went this morning to get new Differential off a guy.. while I was there he said "Tell ya what- why not take it all for the $300" so I got basically an entire front end.. A-Arms, CV's, Differential, Hubs, Sway bar, and steering box.. for $300 bucks. Install of differential will cost me another $250.. but she gets done tomorrow.. Not a minute too soon either.. That little leak yesterday- has turned into full on grease flying mess!

While it's leaking park it in your neighbors drive way? o:)

Sirscrapalot - Probably shouldn't be giving Sledge these kind of ideas.

Hope that solves the problem Sledge.

Don't you just love when you try to love your truck a little (beefed up the ass end about a month ago) and she shows no appreciation at all. Seems like every time I do something to a car/truck that it doesn't necessarily need, something else breaks within a week or two.

KZ- Amen to that brother! I'm bleeding out $ right now. In the past Month I'm at this point:
The Hallway tear-out at Home (I minimize expense.. cause that's what I do.. so I can do it pretty cheap and still look good- but materials are materials!)
Client basically in a nutshell told me my pulling cars was putting his project behind schedule (One was HIS) so I've been hauling overtime there
My wife's Alternator and Battery had to be replaced ($325)
Now My differential goes out- Lost a days pay today going to get it, going to mechanic so he can drain and refill tonight before install tomorrow ($550)
Got my taxes done- another $135.

All good- Hoping this is the tail end of any more "Vehicle Maintenance Issues" for a while- Told the Mechanic- "Hey- if you see ANYTHING in the front end that looks wonky- I've got the parts- let's get em in there while the differential is out! He saw my haul of goodies so he knows exactly what I have. Took a Pic of all the goodies- Obviously differential isn't in the pic as it is already at the mechanics place.. but this is the rest of the "lot" If you are going to be kicked in the sinkers- may as well get an "AWESOME DEAL" doing it!

https://fbcdn-sphotos-c-a.akamaihd.n...18522893_n.jpg

Changed out the Differential yesterday.. All well.. Now maybe I can get back to hauling that trailer- I've got a huge dent to make in all the money that has been flowing OUT but not much scrap $ flowing IN! Been holding off on pulling cars as the front end went from "Concerning" to downright "Holy Crap" status!

Everything else up front looked good, so I may try and sell off the "overage" parts and see if I can't make back some of my outlay of cash!

Good luck with it Sledge. I hope whirring, grinding's all gone now