GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 2 of 2
  1. #1

    Default vacuum, transfer case axle or 4x4 problem

    New member here guys have been reading topics on here for years. As I know just enough to be danderous I never posted a answer cause I wouldn,t trust myself.
    So heres the problem 99 Sonoma highrider 4.3 liter. Put the truck in 4wd a couple months ago to go for a ride on beach. Truck seemed to go in and out smoothly. On way home from beach pulled over for what sounded & felt like a flat while slowing down noticed it was underneath truck. possible transfer case or axle felt like it was trying to engage. Got home found a couple small holes in vacuum line replaced all of them. Problem still there. Replaced vacuum switch on transfer case no oil in lines problem still there. noticed if I undo vac hose to the vac resivor no more grinding sound from axle transfer case area. Push button 4wd shifter on dash shifts no problems can here motor shifting it and no trouble lights.
    Anyway I have read alot of the the other topics on here about vac issues and could not find that directly dealt with this. Any advice would be appreciated. Thanks
    Also with vacuum resivor unpluged I loss my defroster and floor heat and really need to get this fixed as that is the way I am currently driving this.
    Last edited by Pikey; 04-16-2013 at 08:56 PM. Reason: Removed links to another forum

  2. #2


    We replaced vac switch with advanced auto switch didnt work wouldnt draw vac for acuator bought gm switch works great also on a 1998 there is a breather for the transfer case vac switch that is attached to transmission fill tube (dipstick) you might see if its plugged hope this helps

Similar Threads

  1. Transfer Case Problem
    By Lil_Red_Chevy in forum GM Powertrain
    Replies: 4
    Last: 03-09-2011, 10:55 PM
  2. 1996 GMC Transfer Case Vacuum Hose
    By pkbell in forum GM Powertrain
    Replies: 1
    Last: 09-12-2010, 02:25 PM
  3. transfer case problem
    By 09Z71 in forum General Chevy & GM Tech Questions
    Replies: 4
    Last: 08-28-2010, 02:03 PM
  4. Transfer case problem, need advice
    By freightshaker in forum GM Powertrain
    Replies: 8
    Last: 03-31-2010, 01:37 PM
  5. transfer case problem?
    By Roy Lentz in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 0
    Last: 02-07-2007, 09:37 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts