How JustAnswer Works:

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

Ask Duke350 Your Own Question

Duke350, Chevy Tech
Category: Chevy
Satisfied Customers: 86
Experience:  20 years in the automotive repair industry, Currently freelance
Type Your Chevy Question Here...
Duke350 is online now
A new question is answered every 9 seconds

2000 GMC: I have narrowed it down to the front differential

Customer Question

I hope you can help... My 2000 GMC Jimmy S series has a noise in the r/f wheel area. I have narrowed it down to the front differential. Upon inspection it seemed the acuator wasnot fully engageing the 4wd. I then replaced the Vac Actuator and cable both new GMC parts. Still the same problem. When you pull the cable at the entry point on the differential it goes into 4wd but will not stay in 4wd when you let go. Also when it comes out it does not fully disengage making the noise like a clicking or racheting sound. Ther is a sensor at the differential where the cable goes in could that be the problem or I have heard it may be Thrust Washers? Where are the thrust washers and is it a tough repair? How complicated? I have checked the rest of the 4wd everything good Transfer sending power to the front differential via the front drive shaft. Nothing after that no front wheels turning when on four horses in the air. Please help what could it be? About 2 months ago the right side drive axel was replaced. When you disengage everything and disconnect the battery then put it together you can drive with no noise until you activate the 4wd then you disengage the 4wd since it doesn't lock in and the noise appears esspecially in reverse a strong clicking. Please help I really do not want to keep replacing parts that do not need replacement. Let me know atXXX@XXXXXX.XXX Thanks in advance,
Submitted: 9 years ago.
Category: Chevy
Expert:  Duke350 replied 9 years ago.
Do you have good vacuum going to the actuator? There is a vacuum switch on the transfer case for these, and they are prone to going out. Its a bit of a pain to switch out, but its fairly inexpensive. I think it was about $40 at the local GMC dealer.
Customer: replied 9 years ago.
Reply to Duke350's Post: You really did not answer the question.. I do not want to sound rude but, It is frustrating.
It has plenty of vacumn and it is a brand new actuator and cable. Do you any ideas the 4wd front shaft works just no front differential engageing to front axel's. Any ideas?
Expert:  Duke350 replied 9 years ago.

I understand your frustration. This was not meant to be an
answer, it was meant as a start for troubleshooting. I was just trying to
see if you were aware of the switch on the transfer case. Its job is to switch
the vacuum to the actuator (under the battery) on or off. This switch and the
actuator are normally the first parts to fail, and I just wanted you to check
them for me. Since you have a new actuator I want to eliminate the switch. To
check the switch you need to hook up a vacuum gauge to the line that goes to
the actuator and see how much it read while running with the car inXXXXXand what it reads inXXXXX

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... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...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 L Rochester NY
< Previous | Next >
  • 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 L Rochester 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!!!! Alex Los 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. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, 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. Esther Woodstock, 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. Robin Elkton, Maryland

Meet The Experts:

  • GM Tech (Cam)

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
< Last | Next >
  • GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
  • Tim's Auto Repair's Avatar

    Tim's Auto Repair


    Satisfied Customers:

    Have owned a repair shop for 25 yrs.
  • Gary's Avatar


    Chevy Technician

    Satisfied Customers:

    15 years GM master tech
  • Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    ASE Master Certification. GM World Class Certification
  • John's Avatar


    Master A.S.E Automotive technician

    Satisfied Customers:

    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • Don 'Mo Lurch''s Avatar

    Don 'Mo Lurch'

    Auto Mech / Electronics

    Satisfied Customers:

    Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.
  • Neal's Avatar


    Chevy Mechanic

    Satisfied Customers:

    Shop Owner and Mechanic on multiple makes.