QuestionI just bought a 83 Blazer 4wd with auto locking hubs. My problem is in the left front hub. When starting out at low speed a very fast clicking starts in the hub. As the speed increases the clicking gets faster. When I slow down to a stop something under my feet maybe the transfer case or even the hub itself makes a loud clunking noise and everything seems to fall back into place and the clicking stops until I increase my speed again. Sometimes the clicking stops after driving for awhile so my father and I were thinking it might be temperature sensitive but its not alway consistant with that theory. After driving for awhile the left front hub is very hot to the touch while non of the others are. The clicking how ever does not accure when I put it in 4wd high and low. What do you think might be the problem. And is it fixable my a novice shade tree mechanic. Any help you could give me would be greatly appreciated. Thanks for your time.
AnswerHi Robert,
Your issue may be as simple as not following the proper procedure for engaging the 4WD. ALWAYS engage and disengage the transfer case while in NEUTRAL, STOPPED, engine running. Wait about ten seconds for the vacuum actuator to fully engage and roll the vehicle in reverse for about a foot, then engage your forward gear and your 4WD should be locked.
That said, I'm going to answer your second question first if you don't mind. If you've never pulled apart a 4WD hub, please take it to someone who has. It is a pretty complex yet simple design and requires a special bearing socket and if it is not adjusted correctly, you'll likely destroy the assembly.
Ok, If I remember correctly, when you use the auto-lock feature, what is happening is a vacuum actuator, located under the battery tray typically, pulls a cable which engages the front differential assembly. The hubs are spring-loaded and as soon as the axle shaft starts to turn WITH POWER, it overcomes the spring pressure and engages the outer-hub. There is probably some drying grease in your assembly and it is causing the spring to stick which is the light clicking sound you are hearing. The two gears are trying to mesh but the spring pressure is keeping them from doing so.
The noise you're hearing coming from the transfer case is the front driveshaft engaging. If the right-outer hub is having trouble engaging, it leaves the left engaged and that will cause wheel-slip. Since the transfer case is engaged, wheel-slip is kept to a minimum but the front driveshaft, because it IS experiencing slight slip, rides the forward edge of the gear while the rear driveshaft rides the rearward side of the gear. There is only a slight difference, maybe 0.080" of play in the gear teeth, but this is enough to make a vintage set-up like that make noise and act oddly.
I'd guess you'll find your problem in the hub itself, but like I said, unless you're in for a schooling, take it to someone who is experienced with the operation of that unit.
My advice on finding a 'good' technician is: Steer clear of the dealership and 'chain' stores like Firestone, Sears, Pep Boys, Monro Muffler/Brake, Midas, etc. as they usually only employ ONE ASE Certified Tech just so they can say they do and chances are, that guy is the asst. manager or manager and is not in the store to diagnose/repair vehicles anyway. Find a service location in the link below or get some names out of the yellow-pages and do a drive-by. Garages that employ ASE Certified Technicians will be marked with the 'Blue-Seal' insignia. If unsure about whether a place employs Certified Techs, just ask to see their credentials. ALL ASE Certified Technicians will be PROUD to show and display their certificate(s).
Thanks for the question, I hope this information was helpful to you.
Fred
www.knucklebusters.us
570-453-0910
"Re-use is the best form of recycling" Help us recycle by purchasing used parts from us!
Looking for an ASE Certified shop near you? ASE Certified Technicians are the BEST of the BEST!
Click here: http://www.ase.com/bluesealsearch/locator.php
