GMC

GMC Troubleshooting Questions? Ask a Mechanic for Answers

Ask an Expert,
Get an Answer ASAP!

GMC

I purchased a 2008 yukon xl denali awd with 105,000. I have

Customer Question
noticed that when I accelerate...
I purchased a 2008 yukon xl denali awd with 105,000. I have noticed that when I accelerate hard from coasting there is a thump or lurch. This occasionally happens on deceleration as well. I plan on getting a transmission flush at the dealership. Any thoughts?
Submitted: 2 years ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Customer reply replied 2 years ago
Any thing I can check for slop in the driveline?
Answered in 6 hours by:
9/12/2015
GMC Mechanic: Gary, ASE Certified Technician replied 2 years ago
Gary
Gary, ASE Certified Technician
Category: GMC
Satisfied Customers: 17,283
Experience: GCM master tech over 25 years
Verified

I am sorry for the long wait

4X4 ?

did this problem start out of the blue one day ?

how long have you owned this truck ?

Ask Your Own GMC Question
Customer reply replied 2 years ago
AWD, just purchased about a week ago. Didn't notice during test drives bc I was being gentle with the wife in the car. With smooth acceleration it seems to shift smooth. It happens primarily when you get on the gas hard after coasting a little.
GMC Mechanic: Gary, ASE Certified Technician replied 2 years ago

ok

these AWD and 4WD trucks all have a somewhat of a drive line clunk when letting off and coasting then getting back into the gas as these drive line systems by design when you add up the back lash so to say between the transmission and transfer case and rear axle this can be a normal noise heard

but it is best to be sure that there is nothing wrong with the drive line system

we did have some with too much rear axle backlash causing excessive clunking like this and a few rare ones with excessive transfer case back lash also

it is best to have the drive line inspected for the correct back lash first and correct anything that the bask lash is over spec...usually like the rear axle is @ .010 of back lash which any shop can inspect and check with a dial indicator and also the u-joints checked for any play in them

if the specs are normal tolerance or within specs then there is not much you can do to correct this issue

but again the drive line must be checked to be sure

if everything checks out good including the u-joints then this bulletin apply s for this type of issue

# *****: Information on Driveline Clunk Noise - (Nov 18, 2014)

Subject: Information on Driveline Clunk Noise Models: 2015 and Prior GM Passenger Cars and Light Duty Trucks

This Bulletin has been revised to add the 2015 Model Year and remove the Important statement. Please discard Corporate Bulletin Number 99-04-20-002H.

Some customers of vehicles equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, customers of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released. Tipping into the throttle after deceleration can also result in some level of clunk as the driveline is loaded in one direction (coast) then with throttle reapply the driveline gets loaded in the opposite direction (drive). On manual transmission vehicles depressing the clutch while in a deceleration immediately releases load on the driveline and may produce a clunk noise as the driveline unloads.

Note : Compare this complaint vehicle to a like vehicle. If the results are the same, this is a normal condition. For additional diagnostic information, refer to the appropriate Service information.

Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or freeplay (also known as lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more freeplay the total system will have.

The clunk noise that owners sometimes hear may be the result of a buildup of freeplay (lash) between the components in the driveline. For example, the potential for a driveline clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the freeplay from the rear axle gears, the u-joints , and the transmission (common to both vehicles), the 4-wheel drive transfer case gears (and their associated clearances) add additional freeplay to the driveline.

In service, dealers are discouraged from attempting to repair driveline clunk conditions for the following reasons:

^Comments of driveline clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of freeplay (or lash) present in all of the driveline components.

Because all of the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a satisfactory lash reduction.

^While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.

^For additional diagnostic information, refer to the appropriate Service Information.

Ask Your Own GMC Question
Ask Gary Your Own Question
Gary
Gary
Gary, ASE Certified Technician
Category: GMC
Satisfied Customers: 17,283
17,283 Satisfied Customers
Experience: GCM master tech over 25 years

Gary 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:

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

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Gm Tech (Cam)

Gm Tech (Cam)

GMC Mechanic

1,696 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

17,283 satisfied customers

GCM master tech over 25 years

Dave Nova

Dave Nova

GMC Technician

929 satisfied customers

ASE Master Certification. GM World Class Certification

Chris (aka-Moose)

Chris (aka-Moose)

GMC Technician

563 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

255 satisfied customers

18+yrs experience. State Inspector & GMC Diagnostics/Repair

George H.

George H.

ASE MasterTechnician

225 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

Don - Mo Lurch

Don - Mo Lurch

ASE Certified Technician

216 satisfied customers

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

< Previous | Next >

Related GMC Questions
Ron. I have a 2008 GMC Yukon Denali with 150k miles that has
Hi, Ron. I have a 2008 GMC Yukon Denali with 150k miles that has been dealer maintained since purchase, had oil changes at least every 3k miles and all other suggested maintenance done. For the past t… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I just replaced the differential (used) on my 2002 GMC Yukon
I just replaced the differential (used) on my 2002 GMC Yukon XL 1500 and now the traction assist light stays on indicating its "off". Is it related or are there other causes? It was not turning to "of… read more
TIM MOHR
TIM MOHR
SHOP OWNER
Master's Degree
8,037 satisfied customers
My Yukon has no heat in front but heat in the back. I did
My Yukon has no heat in front but heat in the back … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
I NEED A PRINT OUT OF HOW TO REPROGRAM MY DRIVERS SEAT AND
I NEED A PRINT OUT OF HOW TO REPROGRAM MY DRIVERS SEAT AND HEATER IT WORKS BACKWARDS … read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
563 satisfied customers
2011 gmc heat is good on drivers side and cold on passenger
2011 gmc heat is good on drivers side and cold on passenger side after battery replacement … read more
3pac2222
3pac2222
nissan master auto tech
Associate Degree
2 satisfied customers
Turns over but does not run both relays ok. Before i chance
before i chance fuel tank and fuel pump everything was ok … read more
Edward Clayton
Edward Clayton
Associate Degree
1,033 satisfied customers
I have a 2017 GMC Yukon XL Denali we are attempting to mount
I have a 2017 GMC Yukon XL Denali we are attempting to mount a grille guard on. On the end of the frame is a box the dealer says is an Adaptive Cruise Control. Can this be moved to allow the grille gu… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I need to remove the fuel rail line and it won't come up.
I need to remove the fuel rail line and it won't come up … read more
Gunvir Singh
Gunvir Singh
1,712 satisfied customers
Dave, I need to remove the back panel of the front seats to
Dave, good morning! I need to remove the back panel of the front seats to install a headrest dvd player on both seats. Also i need to know how to get access to the inside of the center console to perm… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
No hvac fan, power seats not working and 4x4 switch, 07gmc
no hvac fan, power seats not working and 4x4 switch, 07gmc 3500 classic, could it be the bcm? … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
My 2005 Yukon Denali will not crank, I have replaced the
my 2005 Yukon Denali will not crank, I have replaced the battery, starter, starter relay and the ignition switch as well as new battery cables and new grounding cable from body to engine. The issue is… read more
GM Bob
GM Bob
Automobile Technician
High School or GED
989 satisfied customers
2012 3500 delayed voltage output when pressing the pedal.
2012 3500 delayed voltage output when pressing the pedal … read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
563 satisfied customers
I've got an 06 Envoy with the I6. Started having a slow
I've got an 06 Envoy with the I6. Started having a slow cranking issue on the SECOND crank of the day. Will crank fine, normal speed, first crank of the day. I'll drive 15 minutes to work, come out a … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,943 satisfied customers
I am trying to remove the engine cover on a 2017 gmc sierra
I am trying to remove the engine cover on a 2017 gmc sierra denali 6.2L ecotec 4wd. There is a bolt or clip holding the back next to the firewall Steve… read more
GM Bob
GM Bob
Automobile Technician
High School or GED
989 satisfied customers
Heavy misfire 2000 gmc 3500 sierra 1st 10 miles this am Aok
heavy misfire 2000 gmc 3500 sierra 1st 10 miles this am Aok then misfire and flashing engine light power progressively going down … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
05 Z71 code said front airbag sensor right so i changed it
05 Z71 code said front airbag sensor right so i changed it had battery disconnected and the cables clamped together during process hooked everything back up light came back on now code says airbag sen… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,943 satisfied customers
2002 GMC SIERRA STARTS GOOD THEN IDLE DROPS SO LOW THAT IT
2002 GMC SIERRA STARTS GOOD THEN IDLE DROPS SO LOW THAT IT USUALLY DIES; WHEN IT DOES DTAY RUNNING, AFTER 15 SECONDS OR SO IT RUNS FINE. … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
The left turn signal works off and on. When it works both
The left turn signal works off and on. When it works both lights come on. When it doesn't work the blinking is faster and only the front light works. Replacing the rear bulb did not help. … read more
GM Bob
GM Bob
Automobile Technician
High School or GED
989 satisfied customers
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