Chevy Silverado and GMC Sierra 4x4 Questions



  • rhawneyrhawney Member Posts: 1
    vehicle does not shift into 4wd in either auto 4 or 4h or 4lo. it does shift to low when 4 low button is pushed. switch panel lights appear the same as when system worked. occaisonaly when switched to 4wd it will blow atc 30 amp fuse and then no witch panel lights and service 4wd message of course. I removed front axle actuator and it appears to work fine.
    any advise appreciated
  • havatokerhavatoker Member Posts: 39
    Try new select switch( The push Buttons ), also the connecter at the front accuator will sometimes have a short in it.
    Lots of luck
  • jason2500jason2500 Member Posts: 3
    edited September 2010
    I have a 2003 sierra 2500. I reently shifted the truck to 4 hi ti pull a trailer out of a ditch. i didnt have enough power to pull it out so i shifted to 4lo and pulled it out fine. I noticed whe i got back on the level ground i tried to shift back into 2hi and nothing would happen i ended up having to remove the motor from the transfer case and shift it manually to get home. once i got it back to my garage i reinstalled the motor and now the lights on the selector switch will only come on for a few seconds when i start the truck snd then nothing at all. I have tried a nnother incoder motor that didnt work and i swaped my switch out to my brothers truck and they worked fine in his.does any one know what the problem could be
  • jdsholtzjdsholtz Member Posts: 3
    edited October 2010
    while driving it seems like the trans downshifts and upshifts fast,like a stumble but the engine stays steady according to rpm gauge.could the speed sensor be a problem,and is it on the end of the transfer case? some one told me the tps could be the problem?
  • jdsholtzjdsholtz Member Posts: 3
    it doesnt always kickdown when floored,rpm goes up but trans doesnt kickdown. also noticed a bad vibration when doing kickdown test,sometimes works fine then dont at times.????????? stumped
  • snowchevysnowchevy Member Posts: 1
    I have a 2003 Chevy Silverado 2500HD, the service soon light I have had NEW wires and plugs, and new COIL PAK, I have also had dual put on. I am still experiencing a miss. Okay so I turned around and had the injector cleaned. STILL MISSING!!!! What else could be the problem?
  • jdsholtzjdsholtz Member Posts: 3
    have your o2 sensor checked, they need to be replace around 60,000 miles.
  • rihan5rihan5 Member Posts: 1
    Hi new to this forum.My question is I just bought a 2005 1500 sierra z-71 and when I put it 4hi an turn it makes some bad sounds. Going straight sounds ok.Took it back the dealer and he said it was a normal sound when you turn in 4 wheel(something about the clutches coming in and out.)drive.The mech. said he went and drove two trucks the same as mine on the lot and they both made the same noise. I have a 2000 chev blazer zr2 and it does not make that noise in 4 hi but they said it is a differant drive system.Does that sound about right or should I take it some other dealer.
  • bdwlf2bdwlf2 Member Posts: 1
    Having a problem with power to front axles in 4wd. I put on stands and put in 4wd and all wheel spin. If i hold brakes, the front dont spin. The front driveshaft doesn't spin at all either while there is a load on it. The front axle does engage though. In neutral with 4wd on, the front axle, driveshaft and everything move.

    Now it does go into 4wd low, but still having problems with the power going to front shaft. Again up on stands, all wheels spin great. But i hold brakes and only rear spin. Could this be an actuator problem on transfer case? Bad fluid? Vaccum line? Or is the case just bad?

    All 4wd selections including auto 4wd have same symptoms. But drive shaft does jerk like it wants to spin, just not enough power. 2WD works great, and no funny sounds, smells, or clanking in any selection.
  • lsabourinlsabourin Member Posts: 3
    The dealer is right, it is normal to hear/feel chirping/binding in the front end when in 4hi/lo while turning, especially on dry pavement. And your Blazer does have a different front drive system than a full size sierra. Plus the sierra has a lower gear ratio than your Blazer which also adds to the binding while turning. I have had several Z-71's and they all did it.
  • atteberryatteberry Member Posts: 1
    I have a 2000 GMC 2500HD with the 6.0 adn the 4l80E. I just replaced the transfercase encoder motor which engages the transfer case in and out of each option. 2h, 4h, neutral, 4low. before i replaced it i had a bad encoder, now that i completely installed a new one, which was easy to do, whenever i push the 2 HI buttom, it engages into 4 low. When i push the 4 HI button it goes into 4 low as well. I cant put the transfer case into Neutral at all by holding both 4HI and 2HI buttons, and when i push the 4 low button i get 4 HI???? whats going on with my transfer case. Anything helps.

    Thanks! :sick:
  • asayerasayer Member Posts: 1
    I have been having problems with my 4X4. I have the push buttons. It works sometimes but others it wont. I recently checked both of the motors in the differential and the one to lock in the front wheels. THe drive shaft going to the front wheels locks and i jacked up the front end and the front wheels spin opposite directions meaning its all engaging. I took it out on a county road and it would not spin the front 2 tires in a burnout in 4wd Hi or low. Any suggestions? THanks!
  • havatokerhavatoker Member Posts: 39
    Check to see if your drive shaft is turning while the front wheels are turning, then check your switch, also if you have had any of the wires going to any of the 4X4 parts unplugged without taking the battery cables off, you will have to carry it to some one who has the electronics to clear all that has been done.
    Mine did the same , so I was a fix it my self, when I did see I could not fix it ,I got person with electronics to check it out, there was 25 codes on it and a bad selector switch.
  • dreamjockidreamjocki Member Posts: 1
    I have a 95 Silverado 1500 4X4, the dash gauge shows it's overheating (avg close to 260 range) within just a few minutes of operation.

    New thermostat, radiator & temp sending unit but still shows overheating.

    We installed a manual gauge, this one shows the temp is within operating range & that thermostat is opening & closing appropriately.

    Any suggestions on what to check on the dash gauge? The ground wire is attached correctly but maybe we're missing something else.

    Thanks in advance for any assistance!
  • havatokerhavatoker Member Posts: 39
    Yes , try replacing you dash gauge
  • chanookchanook Member Posts: 1
    Its been intermittently failing the key-start self-test, no LEDs lit behind the buttons, no action when buttons are pushed, puts the "SERVICE 4WD" onto the DIC, happens more frequently in wet weather, and sometimes happens while driving, although, it has never made an un-commanded shift into 4HI or 4LO. Its been doing it for off and on for a few weeks.

    I researched thousands of postings on the Web about this problem, and I have fixed it (for now). In the process, I drew out a wiring diagram of the Transfer Case Shift/Servo Motor, a Pinout, resistance checks with an Ohmmeter that can be done without removing the Transfer Case Shift/Servo Motor and that information is posted here.

    Hope this will help you diagnose this common problem.
  • piatkowskipiatkowski Member Posts: 1
    I recently got a used '08 4WD Chevy Silverado..I upgraded from a '06 2WD Silverado. Well I finally got to use the 4wd but theres this problem while shifting back and forth from 2wd to 4wdHi the floor shifter seems to stick..It seems like ai really got to struggle to shift from 2wd to 4wd..I thoguht it would go smoothly.Am i doing something wrong? Also I seem to have the problem everyone else is haveing when they turn. I hear a grinding noise and my truck shakes when turning, I thought I had snow stuck under my truck what is the problem. It makes no noise in 2wd...can someone help me out here?? thanks
  • gmcustsvcgmcustsvc Member Posts: 4,252
    I would recommend taking the vehicle to your local authorized GM dealer of choice. If you need assistance locating a dealer, please let me know.
    GM Customer Service
  • insbroker2insbroker2 Member Posts: 4
    I read this post and didn't see my issue so I hope someone can help. I have a 1997 K3500 that has 4lo but not 4hi. Replaced the front axle actuator and the ball switch on the transfer case is working. Can anyone tell me what to check?
  • bruce48532bruce48532 Member Posts: 64
    My guess the encoder motor.

    I have a 1999 140k miles have replaced the encoder motor once & and the front actuator 2 times, the dash switch 2 times, rebuilt the transfer case once.

    link shows encoder motors motor&_sacat=&rvr_id=193394075195&MT_ID=335&crlp=1263599956_9887&tt_encode=raw&g- eo_id=491&keyword=encoder+motor&adgroup_id=773792716
  • pvaldez1448pvaldez1448 Member Posts: 2
    I have a 2001 Chevy Silverado and recently the service FWD service light turned on. It all started when I was driving the lights and radio started to flicker on and off as if a battery cable was loose. I went home turned off the truck checked the battery and it was fine and when I turned the truck back on the FWD service light was on. I replaced the transfer case select switch and I am not pulling any codes from my code reader, I am thinking a loose wire? Any suggestions?
  • insbroker2insbroker2 Member Posts: 4
    What does the encoder motor do? And thanks for the help!
  • bruce48532bruce48532 Member Posts: 64
    The encoder motor is an electric motor which is used to shift the transfer case from high to low range. Also included in the encoder motor assembly is a position sensor which sends the actual position of the transfer case shift shaft to the Transfer Case Control Module.
  • insbroker2insbroker2 Member Posts: 4
    "The Electric Actuator/Motor Is Used To Engage Transfer Case In And Out Of Four Wheel Drive On Chevy Truck Equipped With Electronic Shift 4x4. "

    I have a floor shifter and this makes it sound like its only on push button shift models?
  • insbroker2insbroker2 Member Posts: 4
    Can someone tell me where to find a wiring schematic of the 4x4 system on a 1997 K series with a floor transfer case shifter?
  • Duane99Duane99 Member Posts: 11
    About a half pint of Autotrac II transfer case fluid was added to the automatic transmission of my 99 Sivlerado. Is this going to cause problems? Should I change the fluid as soon as practical? It has been in there for about a week already; I cannot feel any problems as of yet.
  • jsharp3jsharp3 Member Posts: 1
    I have a 2004 GMC Sierra with the dreaded "Service 4-wheel drive" message in my display. It happened a few weeks ago and is on-going, although intermittent. One time after turning off the truck (went into a store for some parts) and came back out, it was in 4-wheel low. I shut it off and restarted it and it was back in 2-wheel hi.

    I took it to the dealer and they said I needed to replace the encoder motor. I bought it from them and replaced it. Easy to do, I might add.

    3 or 4 days later, the same message reappeared. I went back to dealer and they said it could be the switches instead. I bought the switche and replaced them (in about 5 min).

    Few more days, message is back. I called the dealer and now they want $90 more to "reset" the code. They say it's not really broke, but I just need to pay them to reset the code and all will be fine.

    My question is, if the parts have been replaced, do I really need to have the code reset or should it reset on it's own. I hate to pay them more money if it doesn't fix the problem.

    I'm in for $90 for reading the code the first time, $400 for the encoder, $90 for another read, $100 for the switch. that's almost $700 and the truck is still doing the exact same thing.

    Any other options for what this cause is. I checked the battery ground and it isn't corroded at all.

    Your help is greatly appreciated...

  • robbintrobbint Member Posts: 1
    2006 4x4 auto z-71 5.3L truck is going into neutral while still in gear. When I push the all-wheel drive button all gears work again I than push 2-WD button and it works for a while as norm. but than will kick back to N again. Makes a loud clunk if I don't stop to put in all wheel. Now it wont ingage in 4 -L ??? any help??? there is some Metalic in the transfer case oil..
  • natedog8895natedog8895 Member Posts: 1
    has anyone found an answer to this problem..I also wanna convert my 02 over to manual 4wd.
  • 02silverado0202silverado02 Member Posts: 1
    Have you yet to find a solution to the problem? If so please fill me in. I just had the same issue with my 02 Silverado. The lights just went out on the 4x4 indicator and I am getting no 4x4 function. I changed the switch and it still wasn't working. Next is the transfer case actuator from what I am told, if that is bad you will lose power to the 4WD. Let me know if this was your solution too. Wouldn't mind saving the $79 if it's the wrong direction.
  • pvaldez1448pvaldez1448 Member Posts: 2
    I ended up taking mine into a four wheel drive shop and it ended up being a short in the wiring. It took them a few hours to diagnose the problem. Hope this helps.
  • djw52566djw52566 Member Posts: 2
    I have a 06 Silverado 1/2 ton 4x4 with approximately 79,000 miles. My "service 4wd" light came on the dash occasionally but the 4x4 still worked, then every time I started the truck the "service 4wd" light came on. I pulled the switch and checked it and think that it was bad (internal lights burnt). I bought a new switch from the dealer, disconnected the negative battery cable and installed it. Reconnected the battery cable, checked the switch, no lights whatsoever, but the "service 4wd" has gone away.

    I've heard that this is common on chevy's. Has anyone run into this problem and if so what was your fix? I've already spent $98 on the switch from the dealer, so I'm commited now.

  • zolten150zolten150 Member Posts: 2
    im not sure what the switch looks like but if there is a ground wire required to to connect to the switch, it will make the light work if it is connected to the right terminal. from what i know, the light wont work on any switch if there isnt a ground hooked up. Does your 4 wheel drive work at all now even with the light off?
  • djw52566djw52566 Member Posts: 2
    It has 4 buttons, top button is Auto 4wd, next is 2wd, next is 4Hi, and finally 4Lo.

    The 4wd does not work whatsoever. I'm sure that I'm now looking at replacing the encoder motor which is between $185-$200 depending upon where you get it.

    Fortunately I have studded tires so getting around town and such is fine, but I own a rental that is located in the mountains and with the snow that we've been getting I might get in there but I probably won't get out without the 4wd.
  • gmcustsvcgmcustsvc Member Posts: 4,252
    I understand you are working on fixing this yourself. Unfortunately, I cannot assist with diagnosing your vehicle. You could have the dealer assist you in diagnosing the vehicle. Please keep me updated on your situation.
    GM Customer Service
  • 96chevy4x496chevy4x4 Member Posts: 1
    edited March 2011
    I have a 96 chevy silverado with the floor 4x4 shifter. But cannot get my front tires any power, 4x4 diagram wont light up either. I have checked the front drive shaft and its fine. i have checked the 4x4 fuse and thats fine, i have check the voltage going to my actuator and that is fine.I tested the actuator and it did not activate, so i bought a new one and that one wont activate. does anyone else know what the problem could be?
    last year i installed a new engine and before it was installed the 4x4 didnt work and as soon as i got it back with the new engine it worked, but has recently gone out again? really strange.
  • lugnutt79lugnutt79 Member Posts: 1
    Has anyone answered this yet.??. I'm having the same problem and getting really tired of messing with it..
  • havatokerhavatoker Member Posts: 39
    Dude, had the same problem with a 2000,so finally , i decided to let them put the computer on it, it had 27 bad codes, after they were cleared it, worked well, but :shades: check to make sure you are getting voltage to the front drive, it won't read 12 volt, more like 3 1/2 volts.
  • jnl798jnl798 Member Posts: 1
    I have a 05 gmc sierra 1500 Z71 the service 4wd light keeps coming on and is now aotomatically shifting into 4low any ideas?
  • gmcustsvcgmcustsvc Member Posts: 4,252
    My best recommendation is to take it to the dealer. Even if only to have it diagnosed. I apologize for you frustrations. Please keep me updated on your concerns. Have a great 4th of July weekend!
    GM Customer Service
  • abe23abe23 Member Posts: 1
    i have THE EXACT same PROBLEM did u figure out what the problem was, this prob is annoying me? if you could email me it would great , [email protected]
  • tmw4tmw4 Member Posts: 1
    My 2004 GMC Z71 had all the lights on the 4x4 sw panel come on and the truck was in 2 wheel dr. Dealer said they reloaded the software to fix it.
  • mountjeezmountjeez Member Posts: 3
    Hi guys....I have a 2001 GMC sierra 1500 extended cab with only 40,000 miles on it. I'm the original owner, so I know it's never been mistreated. Never had occasions to use the 4 wheel drive mode (hi or lo) and always drove in 2 wheel drive. Last week I tried to use it and something is wrong. It shifts into and out of 2wd, 4wd hi, lo and auto fine. The problem is when I'm in either 4wd hi or 4wd lo and I turn the wheels a bit to the left or right to navigate a curve (even starting out from a standing still position), when it starts to move in the direction of the turn, the truck jerks badly in both forward and also in reverse. There is a loud clunking noise every time it jerks. If I'm going straight without turning the problem. All 4 wheels pull and no clunk or jerk. The 2wd mode has no problem whatsoever. Any suggestions as to what may be causing it?????

    Thanks in advance....Wayne
  • stoneybrokestoneybroke Member Posts: 83
    If you read your owner's manual, I think you will find that the truck should be driven in 4 wheel high at least once a month. I usually run mine about a mile in 4wd to keep things lubed. Also, all four wheels & tires should be close to identical or your driveline will windup and pretty much make the steering wheel impossible to turn in 4wd. If you ever plan on using the 4wd, you need to get it checked out by a pro. Hope this helps.
  • diggendogsdiggendogs Member Posts: 1
    Your transfer case is low on fluid. Guaranteed. I own three of these trucks. Good luck!
  • mountjeezmountjeez Member Posts: 3
    Thanks, stoneybroke!! Like a dummy, I never completely read my owners manual and didn't know about driving in 4wd hi once a month. Also, all 4 wheels and tires on my truck are identical.

    I put a call in to GM...they said a dealer had to check it out, so I took it to my GM authorized service department. They checked it out and said there was nothing wrong with it.... that all 4wd's "hop" and clunk when turning on dry pavement and that it's just the way they are built. I find it hard to believe that it's normal for it to do that since it sounds as if something would tear apart in short order if you had to use the 4wd on pavement. But.....they are the experts....not me, so I guess I have to believe them. Thanks again for the advice.
  • stoneybrokestoneybroke Member Posts: 83
    Back to the owner's manual: I NEVER use 4wd on dry pavement. On corners, the ouside wheels will turn at different speed from the inside wheels-thus winding up the driveline. The hop and difficult steering is caused by things trying to equalize. If you have access to a dirt or gravel road, run it once a month to lube things. If you have to run on pavement, find a straight stretch of about a mile. Do you have the push buttons with "auto 4wd" as a choice? If you do, the truck will only use 4wd when a wheel slips.
  • donl1donl1 Member Posts: 112
    I can't believe you didn't know enough not to run a four wheel drive vehicle in 4 high or 4 low on dry pavement ...unless you have an Obama sticker on your bumper. :confuse:
  • 04silvy04silvy Member Posts: 1
    Yeah it is completely normal for it too hop on dry pavement. Because if your turning the wheel your front tires arent going the same speed as your back tires so it jumps
  • garysrqgarysrq Member Posts: 1
    You should avoid turning on dry pavement while in 4wd. This can be extremely bad for the ring and pinion gears in the difs. The problem is that when you go into 4wd it locks the axles so that they are all always turning at the same speed. This sound like it would always be the case but it is not. When you are turning (especially if it is a tight turn) the outside wheels are travelling a greater distance the the inside wheels and thus need to turn at a faster speed. If the axles are locked then this can not happen and causes the hop you are experiencing because one wheel is hopping to either speed up or slow down to match the other. Other than engaging 4wd on a long straight away occasionally for lubrication purposes you should only engage 4wd when you need it, which the vast majority of 4wd owners never really need to do.

Sign In or Register to comment.