Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Cam. I have a 2007 Chev Avalanche. When I'm driving and put…

Customer Question
Hey Cam. I have a...
Hey Cam. I have a 2007 Chev Avalanche. When I'm driving and put the truck into 4wd auto or 4wd hi, a dull grinding ish sound starts ...almost like it's trying to shift into 4wd but can't. Sometimes it will go away. If I stop and put the truck into 4wd hi, I can hear the requisite clunk and it seem to be okay until I try shifting out of 4wd on the fly. If I shift out of 4wd on the fly it makes the noise. If I stop and shift it from 4wd to 2wd drive it seems fine. If I put it in 4wd auto from stop, when I start driving, it makes the noise. Any ideas?
Submitted: 2 years ago.Category: Chevy
Show More
Show Less
Ask Your Own Chevy Question
Answered in 3 minutes by:
12/18/2015
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 30,400
Experience: GM Grand Master Technician 2007. 14 years experience.
Verified

Hi there, thanks for requesting me.

IT sound to start with like your tires may be different sizes or worn differently. So we need to check the ruling circumference.
In a flat parking lot make a mark at the very bottom of each tire. Then drive ahead 1 full turn of the tire until the left front is back at the very bottom. Then compare the marks. All must be with in 1 inch. More than that will cause issues in the transfer case and a noise like you have described.
Ofcourse if you have 2 new tires and 2 old or difference sizes then this test is pointless. All tires must the the same.
Your uncertainty of the noise makes me think the noise is actually the noise created when the clutch pack slips, which is a low odd growling noise that pulses on and off. Does this sound right?

Ask Your Own Chevy Question
Customer reply replied 2 years ago
All my tires are exactly the same. I rotate them every 7-10 000 km.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

O, do the check I suggested next and see please.

Ask Your Own Chevy Question
Customer reply replied 2 years ago
I'm certain of the noise ...just tough to articulate the exact sound.I can tell you exactly the conditions when it makes the noise, though:1) Switching into 4wd auto or 4wd hi on the fly
2) Switching out of 4wd auto or 4wd hi on the flyIt does not make the noise if I stop and shift into 4wd hi and then stop to switch it out.If I stop to switch it into 4wd drive auto and then continue on, it will make the noise when the 4wd engages.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

If you could pinpoint the location of the sound, where would you put it at?

Ask Your Own Chevy Question
Customer reply replied 2 years ago
It's quite a pervasive sound. I thought maybe the front diff but after change the actuator and spinning the tires, perhaps its transfer case. The sound deadening material on the LTZ is decent, so it's tough to pinpoint a specific place.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

Ok, is there any contamination in the fluid of any of the diff or transfer case?

Ask Your Own Chevy Question
Customer reply replied 2 years ago
I haven't had a chance to check either, yet. Still on duty, but I'm trying to get some better ideas for when I take another run at it tomorrow ....so I can avoid replacing stuff that doesn't need. Would you rule out encoder motor? I have one in the box I could probably return.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

My honest thought is the front axle sliding gear itself may either be in backwards or there is a problem there. This could be checked without much trouble, only removing the axle assembly on the passengers side.

Ask Your Own Chevy Question
Customer reply replied 2 years ago
In backwards? Interesting....
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

The leading edge is chamfered to allow it to mesh. Backwards has it flat edges together and it would not engage and the sound you may be hearing is that.

Ask Your Own Chevy Question
Customer reply replied 2 years ago
I'm trying to find a picture on the internet. So far, I've done all my own work on the truck since I got it at 96 000km. It has over 230 000 km on it now. I haven't done anything like that to the axle area. I can't think of when anything would have been replaced backwards.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

Ok, has anyone had this apart?

Did this work properly the last time or last year?

Ask Your Own Chevy Question
Customer reply replied 2 years ago
I had the axles off to install a 6" Fabtech lift. I upgraded the upper control arms at the same time. I also changed the PS wheel hub. I had a pro shop do a proper alignment. It was all done in the summer months, so I can't pin point the first time the 4wd started acting up.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

OK so tires are bigger. This brings me back to the first test I mentioned, before we do anything lets try that and see the results.

Ask Your Own Chevy Question
Customer reply replied 2 years ago
the tires are bigger. They have about ten thousand kilometers on them. They're all the same size. The lift kit is pretty much the same as my dealership put on some of their brand new vehicles. I chayyed with the guy in the accessory department that sells them and they have had no such issues. Did not have four wheel drive issues the whole time I had my lift kit new tires. The aftermarket Pro Shop was very happy with the job I did on the lift and tires. I reprogrammed everything using the Hypertech programmer so much speedometers even correct. I am 99% sure the tires are all the same diameter still. But, with that said I will verify tomorrow.
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 2 years ago

It’s the place to start and it costs nothing. Lets reconnect when you have that.

Ask Your Own Chevy Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a chevy mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 30,400
30,400 Satisfied Customers
Experience: GM Grand Master Technician 2007. 14 years experience.

GM Tech (Cam) is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

30,400 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,621 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,884 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,948 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

2,822 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
I have a 2001 Chev S-10 4.3 4wd. Was driving on the freeway
I have a 2001 Chev S-10 4.3 4wd. Was driving on the freeway doing 70 went to slow down for off ramp the truck made a horrible loud noise like a plane was landing on top of me. Continued driving and ma… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,647 satisfied customers
Equipped with electronic selection 4WD and electronic 60
Equipped with electronic selection 4WD and electronic 60 series OD trans. Light does not alway illuminate on switch and recently, coming out of AWD, I heard grinding when going into 2wd while stopped.… read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
2,066 satisfied customers
When shifting from park into reverse or drive the trans
When shifting from park into reverse or drive the trans makes a grinding noise. 2004 Chev Tracker. It is a flat tow car.… read more
Tim&#039;s Auto Repair
Tim's Auto Repair
mechanic
High School or GED
8,884 satisfied customers
Chevrolet Suburban 1500 LT: My 1996 Chevy Suburban is making
My 1996 Chevy Suburban is making a grinding noise up front when accelerating, going up hill, or when I hit a bump. If I accelerate slowly the noise stops. It is random and seems to shift fine. When I … read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,621 satisfied customers
As a mechanic, I do most small maint. on our vehicles. We have
As a mechanic, I do most small maint. on our vehicles. We have a 2007 Avalanche, needed rear brakes replaced the pads. drove vehicle and it was fine. a couple of days later, noticed a grinding noise a… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Chevrolet Avalanche 1500 Z71: I have a 2003 Chevy Avalanche
I have a 2003 Chevy Avalanche which has a grinding noise in the undercarriage while driving at any speed. The noise dose not affect breaking. No load in the truck box. No leaks anywhere. Do you have a… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Chevrolet silverado 1500 classic: 2007 Silverado 1500 classic,
2007 Silverado 1500 classic, 4.8L, Automatic trans, 4x4.After shifting from four wheel drive into two wheel drive a clunk is heard from underneath the truck, this happens a few hundred yards or so aft… read more
zzdaryl
zzdaryl
Lead Auto Tech
Some college and advanced training
4 satisfied customers
My truck is making a grinding noise..transfer case..i wouldnt have 4wd
My truck is making a grinding noise when i drive. when i put it 4wd it stops. I was told transfer case, but i figured maybe if it was, i wouldnt have 4wd.… read more
AZ_HUNTER
AZ_HUNTER
GM Technician
High School or GED
219 satisfied customers
duramax..2wd..there is a clunk noise and grinding coming from trans
2004 duramax 4x4, got a shift inhibitor message when in 4x4, kicked out of gear and shift pointer started flashing. put back in 2wd and seemed to be working fine. now when first taking off 1st or 2nd … read more
AZ_HUNTER
AZ_HUNTER
GM Technician
High School or GED
219 satisfied customers
chevy: I turn left..someone beating on the hubcaps, grinding
While in 4 WD, when I turn left or right, there is a terrible noise like someone beating on the hubcaps, grinding. I took it to chevy, they say it's normal?????… read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
30,400 satisfied customers
Z71 4x4 that has a transmission or transfer case problem..2WD..engaged
I have a 2005 K1500 Z71 4x4 that has a transmission or transfer case problem. Truck will not operate properly in 2WD mode, only in the Auto mode. You can start out in 2wd but when you let off and coas… read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
30,400 satisfied customers
2002 Chevy Silverado 2500 HD: shift from 2wd..50 mph..clunking noise
I have a 2002 Chevy Silverado 2500 HD 4WD. It does not have 4WD auto. When I am shift from 2wd to 4HI on the fly going anywhere between 20-50 mph, i get a one time loud clunking noise. no noise when i… read more
tech364
tech364
Vocational, Technical or Trade Scho
196 satisfied customers
My 2004 Avalanche with 105000 miles was making noise when in 4WD...2wd
My 2004 Avalanche with 105000 miles was making noise when in 4WD. While driving I switched out of 4WD and the noise stopped. I tried to put it back in 4WD and then the car almost ground to a halt and … read more
frank
frank
Vocational, Technical or Trade Scho
1,892 satisfied customers
s10 blazer: chev..electronic..2wd..get into 4wd ... run engin selector
chev s10blazer 2000...stuck in 4wheel drive electronicXXXXXcontrol ..auto... 2 hi....4 hi.....and 4 low..was in 2wd tried to shift to 4wd normal way didnt work ..so i looked in the 2000 blazer book th… read more
sldcountry
sldcountry
auto tech
Vocational, Technical or Trade Scho
28 satisfied customers
envoy: chev..4.2l v6..making a clunking sound at around 40kmh
I'm test driving a 2008 Chev envoy 4.2l v6. When its in autoXXXXXit is making a clunking sound at around 40kmh. this can't be normal, is it? It's almost as if it's going in and out ofXXXXXandXXXXX… read more
tech364
tech364
Vocational, Technical or Trade Scho
196 satisfied customers
Chevy Suburban: 4x4..a loud metal clunk..axle..4wd..accelerating
My 1997 4x4 Chevy Suburban has a loud metal "clunk" from the area of the front diff/axle periodically. Doesn't matter if it's in 4wd or 2wd, speed doesn't matter, nor does braking or accelerating. Som… read more
classictech
classictech
Consultant
Vocational, Technical or Trade Scho
108 satisfied customers
2002 Blazer: Im driving along in 2WD at 55-60 mph (..hill..000 miles
My 2002 Blazer just started making a loud whining noise when I''m driving along in 2WD at 55-60 mph (and slower) and usually after I''ve come up a hill. It all of a sudden starts making at first a low… read more
goodwrench9124
goodwrench9124
Lead Tech/ Shop Leader
Vocational, Technical or Trade Scho
2,571 satisfied customers
1994 GMC: it started making a horrible grinding noise..wheel drive
Hi, I have a 1994 GMC 1500 4x4 truck and it started making a horrible grinding noise when I drive. Yesterday when I put the truck in 4x4 it was grinding but seemed fine when I took it out, but today t… read more
Expert
Expert
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x