Chevy Silverado and GMC Sierra 4x4 Questions



  • havatokerhavatoker Member Posts: 39
    Sounds as though you a have a problem with the switch itself, although it could be the encoder on the transfer case , me--- I would have it checked at a transmision shop where they have a computer to check it.Every time you unhook a wire on the truck , you should have the + cable off the battery, cause this puts another code into your main computer, I fooled with mine , knowing I could fix it , but after a few months carried it to a transmission shop , it had 25 codes on it , cost me a hundred dollars but it was worth every penny.
  • tje1958tje1958 Member Posts: 2
    Needing help to determine what my problem is. I was driving home on the interstate with my 4 HI on without realizing why my truck seamed loud ( thought it was my exhaust). After a several miles the noise stopped. When I got in my truck the next day I noticed it was in 4 HI but the front wheels would not engage. The 4 HI light comes on just fine when pushed as does the 2 HI. Does anyone have an idea of why the front wheels won't engage? I really hate to take it to the shop (can't afford it).

    Thanks in advance,
  • bruce48532bruce48532 Member Posts: 64

  • havatokerhavatoker Member Posts: 39
    Pull off the skid plate , then unscrew the actuator,(long ,about 8in. long with a plug in) then have someone to switch the truck on to see if the actuator is kicking in and out, if it is not moving when you push the button from h to L ,then it would be the actuator, If the actuator is out, it would be ingaging, if in, its not.
    Don't be afraid you will lose grease, it will only drop out a few drops.
    IF the actuator is working, it can be the front gears.
    lots of luck
  • ken_s1ken_s1 Member Posts: 1
    Hi there,

    I'm new to the forums but I've been reading them for a few days doing a bit of research. I've got a 2003 Silverado 1500 with the electronic switch on the instrument panel to engage the 4 wheel drive. I'm noticing what I would call a grinding noise coming from the drivers side front when I activate either the auto 4WD or 4 hi. Its very noticeable when I make the switch on the move and will persist until I switch back to 2DW. I could not hear it when I engaged the 4WD and drove in reverse up my driveway...its a pretty long driveway so I think I would have heard it but I can't be sure.

    From other posts on the board concerning similar problems, I'm leaning in the direction of the wheel bearing on that side but I wanted to pick a few brains here to be sure.


  • havatokerhavatoker Member Posts: 39
    Front whell bearing, internal front carrier bearing, check your Tranfer case housing to see if the bols are loose, and hope that it is not locking differnial.Jack up the front end , Turn the tires by hand and see if it makes a rough noise.
    Could also be a u joint in front drive shaft
  • svgasvga Member Posts: 3
    Hi all,
    I have read thru all of the relevant post in this section and I haven't read anything about the problem I am having.

    I was cruising down the freeway at about 65-70mph in 4Hi and I noticed what I can best describe as a clunk from under the truck. It was very intermittent and disappeared when I switched to 2Hi. I had a jeep several years ago and I remember what it feels like when the chain is slipping over the gears....this feels very similar. I checked the fluid and found it was low. I filled the case and went for a test drive. I now noticed the same problem only under acceleration at speeds above 10-15mph. At this point I figure the chain has stretched due to lack of oil.

    Yesterday afternoon I tried the 4Hi again and notice there is now no problems, no "clunk" or what feels to be chain slippage. I drove it around for several hours without issues. I drive into work this morning and it does it starts doing it again. I went out for lunch and tried again...this time when I press the 4Hi button I hear a grinding noise under the truck. I am thinking maybe the 4 wheel drive is not engaging fully?? Could a bad encoder on the transfer case be my entire problem? Maybe multiple problems? Any help would be great!

  • jbeyhijbeyhi Member Posts: 6
    it is not the lock. it is unlocked and neither handle will open the door. any other trick?
  • svgasvga Member Posts: 3

    I tried the 4Lo position and I am having no problems at all. In 4Hi, it mostly makes grinding noises in forwards and reverse. I am leaning towards the TC motor.

  • 00silveradoz7100silveradoz71 Member Posts: 1
    A while back i caught myself driving in 4 hi going bout 60-70 mph. I stoped and put it back in 2 hi right then. been driving only bout a mile. Also I broke my drivers side cv axle pulling a 2500 out. When I put it in 4Hi of 4Lo i hear it sound liek its locking in, put my front passenger side wheel will not spin. Any help there?
  • rev4revrev4rev Member Posts: 11
    My 1998 Chevy 1/2 ton was spitting gear oil out the breather hose after a long trip.
    Drained the oil and there is no metal.
    Is it possible the actuator stuck?
  • lowcostlowcost Member Posts: 5
    hi i have a 2004 gmc 1500 the vservice 4wd light is on and the push button indicator light is stuck in 4hi the truck also only moves if you start it and drive once you stop its like its in neutral please any help would be appreciated
  • lowcostlowcost Member Posts: 5
    hi i have a 2004 gmc 1500 4x4 the truck dash says service 4wd and the push button is stuck in 4hi and the truck will only move for a bit then you have to shut the truck off restart it and it will move alittle more please help im lost !
  • havatokerhavatoker Member Posts: 39
    Looks as though you hit a bad question, But , carry it to a transmission shop , they can run a scan on it , and can tell you what the problem is, if its just codes , then it won't cost very much to fix it.
  • jemlmmjemlmm Member Posts: 1

    I have a 1995 chevy Silverado 4X4 with the same problem, I was wonderring if you could tell me where you found the shcok mount from the dealer for $102.88

    [email protected]
  • lowcostlowcost Member Posts: 5
    changed the fluid and fillter it was black ,,it seems to be working fine now i hope
  • felix19felix19 Member Posts: 1
    How do I access the rear brake drum on a 2000 Silverado 3/4 ton pickup?
  • tje1958tje1958 Member Posts: 2
    Ended up taking the truck to the dealer to have it diagnosed, turns out the chain had rubbed a hole in the case, the oil leaked out and turned my transfer case into a scrap bucket. They did give me an estimate on the repairs, $2,250. Looks like I will have a 2 wheel drive for a while. :sick:
  • havatokerhavatoker Member Posts: 39
    Just check out the posts on ebay, you will find one, but make sure you get the right one.
    go by the tag on the rear of transfer case.
  • roberobroberob Member Posts: 1
    my 2005 silverado has a problem in auto 4 wd while driving feels like its going in and out of 4 wd no slippage of tires this happens on dry pavement ?
  • havatokerhavatoker Member Posts: 39
    You should not have it 4X4 Auto when driving on dry highway !!!!!!!!!!!!!!!!!
  • elkaholik3elkaholik3 Member Posts: 2
    I have a 2005 GMC sierra the T-case slips into neutral when trans is down shifting. or when truck bounces in the woods. the 4x4 switch works fine. Does anyone else have this problem or know what it is thats messing up.
  • concretejunkieconcretejunkie Member Posts: 2
    I have had this 2005 gmc 1500hd crew cab (w/130,000 miles) for a couple of years now. Its been a REAL good truck, I work construction & pull a 12' tandom trailer loaded w/ my equiptment- all over AZ. I'm real faithful on the maintenance & I do alot of it myself. On monday when i started up in the morning the transfer case control switch briefly lights up then goes out & the 4wd service light comes on..other mornings the switches stay lit up & no serv. light. Last thursday while driving on I-10 in phx the truck just slipped outta gear & my control swithches were not lit up anymore.i pulled over shut off the truck & turned it back on..then it was fine.. still with no lights at switches & serv. was light on....BUT IN GEAR. It did it again about 15 miles later.( at least it was a 1/2 mile from home) I tried the same process again but nothing would engauge. We finally got it home( thx father-in-law) I called shop made appt. The next day it started up fine with control switch lights. As i drove it to shop & it jumped outta gear again ,(control lights off & serv light came on) after driving about 8 miles...WTF! can a transfer case cause all this???
  • gmcustsvcgmcustsvc Member Posts: 4,252
    I am from GM Customer Service. Did you take the vehicle back to the dealership and have them look at it again? What is the VIN of the vehicle? Is the vehicle still under warranty? Thank you,
    Mariah GM Customer Service
  • bruce48532bruce48532 Member Posts: 64
    My guess the tran case actuator is is bad, I had to replace mine at apx 110k, the mtg face of where the it attached to the trans case looked like it had tool marks from the machining process that caused it not to seal properly to the trans case. I put some jb weld on the face and replaced the actuator now some 20k later its still working fine. I did have to rebuild the trans case apx 10k ago not sure it was related to the bad seal around the tran case actuator but I'm sure it did not help.
  • concretejunkieconcretejunkie Member Posts: 2
    edited April 2010 was the actuator/encoder motor. i guess when this goes out the control module goes into a fail safe mode & dis-enguages preventing more damage to the transfer case. the first shop plugged it in & quoted me $800 to $1100 to fix but that includes a new control module & ripping apart the transfer case for exploritory reasons...hmm...dont think so??? i found another place that was refered by a friend..they found that it was just the encoder/actuator & fixed it for $540 out the door. these guys were real honest & had the "if its not broke.. dont fix it" philosophy.why put a new control module in it when this one works fine. they put a new actuator in, road test, another look-over, plugged it in to see if its spitting out any other codes.. & now it works great & im not out a boat load of $$$
  • sha3529sha3529 Member Posts: 1
    I started hearing a rubbing/grinding noise coming from my front driver side. I jacked up the front end and removed the driver side tire. When I rotate the brake disk I can hear the noise coming from around the front differential. There are dark areas around the seals as if it would be leaking fluid, but I have never seen an oil spot in my parking spot on a cement slab. It makes the noise no matter if it is in 2wd or 4wd/forward or reverse. Could the noise be from low gear fluid? Or maybe a bearing?
  • havatokerhavatoker Member Posts: 39
    Did you check the brake pads, if so and they are good , check to see if it goes in and out of 4X4, if it does , then it could be the out side bearing( depending on miles ),if there are quite a few miles then you have to take it step by step,first remove the outside bearing, then turn the shaft, if you still hear it or feel it then it could be an inside bearing, this going back to the amount of oil in the front housing,
    I hope this helps
  • shaneb8shaneb8 Member Posts: 1
    i have a 02 silverado 1500 Z-71 with a NP-246 transfer case which I have had some issues with for which I found hard to get any help with so I thought I'd share my story, which is not yet over, in hopes I could help out someone who was in my shoes. It all started with a wierd whine or grind when in reverse on pavement. It then progressed into an all-out grinding that sounded like the truck was about to fly apart. I had a couple of local guys listen to it and they both said "rear end". I didnt think so. I jacked it up and put all 4 tires off the ground, using stands off course, and while running put in low 1 so i could get a good look at this noise. It was coming from the front output shaft of the transfer case. I did notice right away that the front drive shaft always turns, no matter what position the transfer case is in. 1 GM tech told me this is wrong, 1 said this is right? I then made my biggest mistake of this whole ordeal, I took off the transfer case actuator. WOW what a mistake! This thing came off easy and took me 3 hours to get back on. I was later told, dont know if its true, but if the lights are working on each of the dash switches, A4WD, 2WD HI, 4WD LO, 4WD HI, its ok. So to finish this up a tech told me to put some lucas oil treatment in with the auto-trac II in the transfer case and it worked! no noise! Im outta space, hope this helps somebody.
  • havatokerhavatoker Member Posts: 39
    edited May 2010
    Hope it was synthetic Lucas you put in it , also sounds as though it was low, and the drive shaft does turn any time the truck moves
    My thoughts
  • daarrvedaarrve Member Posts: 2
    Yes, it has helped me, I have a 2000 6l 2500 series and I am having the grinding/growling going on. I am going to flush the transfer case, fill it up with the proper lubricant and some Lucas oil stuff, btw, how much Lucas did you add?
  • daarrvedaarrve Member Posts: 2
    Why synthetic Lucas?
  • havatokerhavatoker Member Posts: 39
    It takes a little over 2 quarts of the transfer case oil that you have to add, it is synthetic , and you have to add the synthetic Lucas , use a quart of synthetic Lucas , then finish it off with the synthetic that is reccomended for transfer case.
    hope this helps
  • halbesmahalbesma Member Posts: 2
    I have a 2004 chevy silverado 1500 Z71. I am looking to put on 20x9 XD series monster rims, and A/T what kind i havent decided yet. But I went and talked to a dealer of tires the other day and he said i will need to put a lift on so my questions here today are what lift kits either suspension, body or level kit would you reccomend and what A/T tires would you agree to look nice and not be to expense please help i need to know ASAP!!! :(
  • halbesmahalbesma Member Posts: 2
    I have a 2004 chevy silverado 1500 Z71. I am looking to put on 20x9 XD series monster rims, and A/T what kind i havent decided yet. But I went and talked to a dealer of tires the other day and he said i will need to put a lift on so my questions here today are what lift kits either suspension, body or level kit would you reccomend and what A/T tires would you agree to look nice and not be to expense please help i need to know ASAP!!! :confuse:
  • zaktomzaktom Member Posts: 1
    I was driving down the freeway and I heard a loud bang. I thought I blew a tire because I got a bad shake/vibration right away. I pulled over and all the tires were fine. No fluids dripping. I was able to drive it home, but at low speeds because it feels like I am driving on rumble strips the whole time. I got it home and put it into 4wd with no problem, but the service 4wd light came on. Now it will not shift out of 4wd. What could have happened?
  • djohandjohan Member Posts: 1
    Recently picked up the vehicle....very nice ride. The previous owner hauled something in the cab that chewed up the lower dash. I can easily fill and texture the spots, but can't find the correct color vinyl dye (paint) SEM has some that are close, but still way off. GM describes the trim color as "pewter" on the orgininal window sticket. Any ideas out there? Looking for a rattle can...

    Thanks a bunch

  • chuck4wdchuck4wd Member Posts: 1
    Hey Guys. My service 4wd light came on and won't go off. I tried changing the switch on the dash no luck. I brought it to shop with the computer. It said I had a bad speed sensor. Has any one changed one before. Where is it and can I do it myself. Thanks
  • padia36padia36 Member Posts: 1
    Did you have any luck fixing your problem? My service 4WD came on then my problem is similar, mine switches from Auto FWD randomly. Then sometimes when I get in the truck there are no light on the switch. It will be in 2WD, assuming this since it runs fine, but if I try to switch to 4WD, it deffinetly does not engage. I let it sit for awhile, get back in and lights are on and the switch works fine both in ad out of 4WD. My service 4WD light comes on intermittently. Any help would be great. :confuse:

    Thank you,

  • gmcustsvcgmcustsvc Member Posts: 4,252
    Hello Padia36,
    I apologize that you are experiencing a concern with your vehicle. Have you had a dealership look at your vehicle and try to diagnose the concern? Thank you,
    Mariah GM Customer Service
  • Duane99Duane99 Member Posts: 11
    sounds like your in-dash pushbutton switch module may be bad. It is a common problem. Mine was okay, however. My problem was the transfer case encoder motor.
  • Duane99Duane99 Member Posts: 11
    The speed sensor replacement was a recall on my 99 silverado.
  • nolioz71nolioz71 Member Posts: 1
    edited August 2010
    Hi I'm Nolan and I have a 2005 gmc z71. I have never had any problems getting my truck in 4wd, but then when i try to take it out i just can't do it. when i hit the 2h button it lurches even when truck is off but will not go into 2wd. and when i try to go from auto to 2h it will just go into 4h. i would like to have your advise on this and any you can provide would be greatly appreciated
  • Duane99Duane99 Member Posts: 11
    sounds like either the pushbutton switch module is bad or the transfer case encoder motor.
  • chrishojo500sschrishojo500ss Member Posts: 1
    hey guys its time for tires what i got is a 2009 1500 silverado and i want to go from a 265/65/18 which is 31.6 inch to a 275/70/18 which is 33.2 inch i have the lift/level kit in it. i just wondered if anyone has done this and had any problems. . . . .rubbing, ect
  • ramzfanramzfan Member Posts: 1
    Hi. My 1996 GMC just quit going into 4 wheel low or high. When I push the 4hi button it just blinks. Same with the 4lo button. I checked the fuse and it was blown.
    I replaced it with a new fuse and it blew as soon as I pressed the button. Any suggestions? I sure would appreciate some help.
  • jazbbjazbb Member Posts: 1
    My 2000 GMC 3500 dose the same thing, i ask around at a few shops, and they said the same thing, "stop before you shift"........
  • huntergirlhuntergirl Member Posts: 2
    recently my service light came on to service my 4 wheel drive. i had it hooked up to the code machine to find out what was wrong and the code reader came back with a 0 saying the truck was running fine and there were no problems but the service light for 4 wheel drive still comes on and i have all ready checked the automatic transfer case fluid and it is fine. does anyone have an ideal of what could be causing the message to continue to come on also i have not used the 4 wheel drive since february 2010. any help would be greatly appreciated.
  • havatokerhavatoker Member Posts: 39
    First of all, is your front wheel drive kicking in. To see that it is, unplug the actuator , then un screw it from the front drive then plug it back up to see that it does extend out when put in 4X4, if it does then there are three sensors that work the whole system ,on the top and side of the transfer case, have them tested.If it does not extend , then it could be any thing in your system that could cause it.
    I dont know who checked it for you , but they have to have years of experance to perform this test.
    If you are not confident in the person that performed the test , then have some one else to check it.
    Lots of luck.
  • huntergirlhuntergirl Member Posts: 2
    thanks for the info. i will get my mechanic to look at this for me. what i have tried so far i could do myself but i just needed an idea of what else i should get the mechanic to look at without being charged for something that has already been checked. thanks again huntergirl
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