Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!

Vibration / Noise GMC truck 1999

marcmarc Member Posts: 21
edited March 2014 in GMC

I just bought a new 99 GMC full size pick up 4x4.
When driving about 40 mph I hear and feel a slight
vibration. It reminds me of when you drive over
those groves in the road to help drainage. Or
those wake up ridges in the road that are there to
wake you up and let you know a stop sign is ahead.
It is very slight but I wonder what it could be.
Someone said it could be a locking toqure



  • quadrunner500quadrunner500 Member Posts: 2,721
    Is it a Sierra or C/K ?
    I have '99 Silverado, and have noticed what you describe. It is indeed very slight, almost not noticeable, and not all the time in any case. On the C/K's I have heard some people say there is a vibration under the floor from the catalytic converter heat shield. But this is definitely not a rattle. I haven't worried about it, but have noticed it occasionally, probably at about 40 mph, and mostly when I step on it a bit, let off, step on it again. Perhaps it is the lock-up torque converter dithering around the lock-up point???
  • 34363436 Member Posts: 25
    I have a new GMC that has the same thing but mine is getting worse it does it between 35 and 50 mph now. It was at just 40 mph like yours when I first noticed it. I have 3300 miles now, the dealer talk to gm at 2000 miles when i took it in for the vibration. Gm said that they know about the the vibration and are working on it. My dealer said it could be a while before the have a fix. Gm says it is a exhaust vibration but I think it is the torque converter but I'm not a mech. just my opinion. Let me know if you get a fix so I can tell my dealer.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Exhaust vibration seems more likely to me too.
  • bob85bob85 Member Posts: 8
    I had this same vibration that go worse from 1000 to 1500 miles on the odometer. It was a vibration that was under the passenger seat and sounded like it went down the exhaust track. I complained several times to the dealer and they tightened heat shields and such. Finally they put recorders under the truck and isolated it to the front transfer case. They talked to GM and GM sent an entire front transfer case which they totally replaced. Now the vibration it gone. The mechanic said that the case wasn't faulty but that someting was "out of harmonic balance". 1500 Sierra 4x4
  • dodgeramdodgeram Member Posts: 202
    Looks like the new gm trucks aren't perfect after all!
  • bob85bob85 Member Posts: 8

    You obviously have nothing constructive to add to this Thread. I would personally take my new Sierra to the dealer every day for repairs before I would consider any of the dodge trucks. We all play the odds with new cars, no company makes 100% perfection but you stick with the people who make the best product for your needs and can fix whats broken (if it occurs). If that is a dodge for you, then fine. Posts like yours (whether pro chevy or other) uncover ones own insecurity about the truck they chose
  • markbuckmarkbuck Member Posts: 1,021
    My new vinyl bench seated Silverado is slightly quieter than my buddies F350 SD CC lariat leather seated truck (says he). For the same price though, I'd rather have the SD (he paid an extra $12K.....

    Dodge would be my third choice.
  • cookie1cookie1 Member Posts: 68
    Hey dave40,

    Are you sure you are not one of the original
    Beach Boys since you have nothing to add except
    'good vibrations'?
  • reeferreefer Member Posts: 37
    Refer to my and other postings further back on the topic list under "tranny noise." The grinding/vibration noise at 1000 to 1500 rpm is very common and seems to be a problem with the truck shifting into OD. GM knows these trucks need their computers recalibrated to fix this problem. The question is: when will the dealers have the software they need to recalibrate our trucks' computers. GM is once again selling us beta (to use computer terminology) trucks and letting the consumer do the product testing for them.
  • marcmarc Member Posts: 21
    Hi talked to a Chevy mechanic and he said he fixed one that was caused by a brake switch. He said it was tripping up the converter or something like that. Of course the GMC mechanic told me they drove a new one and it did it so it is normal.
  • reeferreefer Member Posts: 37
    Contrary to what the mechanic said, I do not believe it is normal when a brand new Sierra truck makes a noise most consumers would not tolerate in a Chevy Cavalier. My new Sierra squeaks over every bump, has windshield molding that snaps like a popcorn popper at 55 mph, and has the all too common driveline "growl" at 1000-1500 rpm. In comparison, my 96 Chevy work truck seemed like a Seville.
  • quadrunner500quadrunner500 Member Posts: 2,721
    You might be happier in a Seville.
  • reeferreefer Member Posts: 37
    Not true, I am happier in my Ford Windstar ( the Lincoln of mini-vans.) However, I just expect more from a new truck and am simply stating that the quality of finish is not up to the level that I have experienced with other new GM vehicles. I think the strike and the rush to get these trucks to market resulted in GM making compromises that are unfair to the consumer. I still like the truck over a Ford or Dodge or I wouldn’t have bought it. I plow snow and I couldn't even do that with a Dodge or Ford 1/2 ton off the lot. I will reserve further judgement until I see how the dealer resolves the problems. I am currently waiting for the computer re-flash ( the GM calibration site now has a part number for my VIN ), if the new windshield molding dies not stop the windshield noise I will silicon glue the molding down and that will take care of that, and I am sure if the dealer tries, he can find the source of the body squeaks and fix them. If that is all the trouble I have with the truck for several K miles that will be fine. I am just a little disappointed is all.
  • quadrunner500quadrunner500 Member Posts: 2,721
    I located my cab squeak myself, with a 17 mm socket. (I think it was 17)

    I simply got under the truck, and tried tightening on the cab-to-frame mounting pad bolts. The one that squeaked when I torqued on it with the socket wrench, was under the passenger side cab towards the rear, just behind the door.

    I told the dealer which one, and he replaced the pad and bolt, no more squeak. Since there are only about 4 of these for the cab, I doubt it will be hard to find the one causing your squeak.

    Let us know how you come out on the windshield molding and driveline growl.
  • reeferreefer Member Posts: 37
    Thanks. It is 18mm I believe. I think I know the one that is causing the squeak. I had DeeZee FX running boards put on and the installer used the cab mounting bolts to secure the board supports. The squeak was there before the boards were installed and is still there although the sound is slightly modified. I will ask the dealer to replace the mounting hardware.
  • knoeckknoeck Member Posts: 1
    I own 99 Silverado and noticed a growling and vibration when in 4wd or auto 4wd at speeds of 45-60 mph. It was almost intolerable on a trip I took this last winter. Was wondering if anyone else has had this problem. Chevrolet told dealer this this is normal because of 410 gear ratio. Sometimes sounds like it's going to fly apart. I contacted Chev by phone in Jan. and it took till April for them to respond. In my business and personal we currently have 8 GM trucks and cars, but this will be my last. If you have a 99 Chev or GMC give your 4WD a try.
  • rkhrkh Member Posts: 11
    knoeck! see #654. Ran into this problem last March. Ask dealer to show you GM March bulletin acknowledging problem, but not having a fix. There has been a lot of input here on what the problem might be, but to date I don't think GM has issued a solution. Good Luck.....RKH
  • quadrunner500quadrunner500 Member Posts: 2,721
    The driveline growl most have been posting about refers to 2wd mode.

    In auto 4x4 mode, you are hearing the front driveshaft rotating under your feet.

    In 4x4 high, you're hearing that but also growl whenever the front wheels are not turning exactly the same speed.

    I think 45-60 mph sounds too fast for most 4x4 driving, although I am not telling you how to drive. I find I seldom need 4x4 or even Autotrack except under very slippery or unusual circumstances.

    When I do engage 4x4, there are some pretty loud engagement clunks/clangs or noises as it switches in or out.

    Beyond those observations, it seems to work well.

    And if you are driving in 4x4 or Auto because of icy roads, you are also probably getting quite a bit of road noise to accompany the noises the driveline makes. Or if you are in 4x4 or auto and driving over dry pavement, you could expect some noises since it is designed to be a part-time system.
  • reeferreefer Member Posts: 37
    Talked to my dealer today and the truck goes in next Tues. to recalibrate the PCM for the driveline growl. He will also replace one of the windshield moldings for the wind noise problem, but I don’t think that will work. I talked to my glass repair shop today, and they advised me not to use silicon sealer to glue the molding down. They said the silicon is incompatible with the urethane adhesive used to attach the windshield. They advised using two sided automotive tape to secure the molding, and they can do that. That is probably what I will do.
  • chevy4mechevy4me Member Posts: 203
    Has anyone with the low rpm vibration had this problem fixed ? It is most noticable in first gear 1000-1500 rpm range .
  • reeferreefer Member Posts: 37
    Thats's exactly right. The woman on the customer satisfaction line I talked to said they all do it and the engineers are aware of the problem. We should not let GM cop out by eventually telling us that this noise is normal. At GM's computer recalibration web page, there is a part number for the computer reprograming to address this problem for my VIN. I assume there are part numbers listed for other VIN's. The page is <<A HREF="http://calid.gm.com/vci/html/getVCI.html">http://calid.gm.com/vci/html/getVCI.html&gt; Go there and enter your VIN and see if information comes up regarding part numbers to fix your problem.
  • quadrunner500quadrunner500 Member Posts: 2,721
    They may all do it, but to a greater or lesser degree. Mine started out with it, but it has all but disappeared on its own after 8000 miles.

    Better lucky than good.
  • quadrunner500quadrunner500 Member Posts: 2,721
    By the way, I wonder if some interaction with new tires could have something to do with it?
  • reeferreefer Member Posts: 37
    Took Sierra into dealer last Tues. He flashed the PCM with the latest updates. The driveline growl seems to be fixed. He replaced the right side windshield molding and so far it has not become noisy. The left side molding was still noisy so I used 3M black weatherstrip adhesive to bond it to the glass and that has stopped that noise. My glass repair shop said it was safe to use.

    The dealer tried retorqueing the body mounting hardware and lubricating them. They were quiet for about 24 hours and then began to squeak again. The dealer said to give him a couple of weeks to see whether he could learn anything new about the squeaky mounts. I will call him in two weeks because I doubt he will call me first.

    Thought you might want to hear this update.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Thanks for the update Reefer. But keep after your dealer about those squeaky mounts. Don't let them brush it off, at your annoyance. My dealer replaced the bolt and pad. Not sure why your dealer didn't, since just re-torqueing the bolt didn't work on mine when I tried it. I doubt they will learn anything new in two weeks. Maybe they don't have the part in stock?

    Remember what your mother told you...the squeaky wheel gets the grease. Same for mounting pads/bolts. Good luck, and don't let them off the hook too easily.
  • scrawscraw Member Posts: 28
    Hey Chevorlet 1/2 ton owners... for squeaks in the suspensions have your dealers look a the front coil springs where they go up in the pocket I bet they will find that spring is rubbing on the front right spring support and the left rear spring support.... the only repair is to have a frame shop move this support by bending and pulling forward on the right front about a 1/2 inch and on the left rear support the same this will undoubtly make it quieter seen it done it, It works
  • steveferre1steveferre1 Member Posts: 1
    I have 3400 miles on new GMC Serria. I am finding that there is a shake in the truck when I cruise between 60-75 MPH. I also noticed that there is a crackeling in the windshield at high speeds. My dealer says the crakling noise is due to the bug guard?? and says that the shaking is just how the truck drives. I am not happy and have contacted GM about the problem for resolution. Does aybody have any suggestions??
  • g8trg8tr Member Posts: 77
    Check post #654- Silverado vibration prob. There are quite a few of us that are having this problem. Fortunately, we have a service tech. who contributes to the board and has found some real solutions to the problems.
    If you have General tires on your truck, quite a few people ((myself included) have tires that have lateral run-outs and shake like crazy at 65-70 mph. Supposedly General is going to replace all of the bad tires. We'll see.
    It could also be the hubs. Check out the postings to get all of the details. The last 40 or so postings is where the real info. begins.
    Good Luck!
  • jrls0929jrls0929 Member Posts: 3
    My truck has 5000+ miles and I have noticed a crackling noise that seems to be coming from around the windshield area when I get to around 50+ mph. It started when it had 1000+ miles on it. Will be taking it to the dealer on Monday. Does anyone have any information on this crackling noise?

  • mksalemmksalem Member Posts: 42
    Go read the first posts from topic #689 - your noise is fairly common and can be fixed either at home or maybe (if they are cooperative) at the dealer.
  • lintlint Member Posts: 2
    Has anyone had any trouble with a door rattling? I have already had it in the shop once for this, and now it is rattling again. I have a '99 sierra 4x4
  • squanksquank Member Posts: 4
    If your "rattle" is a sort of random tapping sound that seems to come from inside the door or cab - but low and behind the driver/passenger - check underneath the cab, just behind the door. There are some cable ties which span the joint where the cab sits on the frame - may be a ground or something - these were loose on mine and the noise was generated when they swung back and forth behind the bolt head. Noise stopped after tightening them a bit. Takes a large wrench and some hernck, but they will tighten. There is one on each side of the cab. Have seen this complaint from others as well.
  • squanksquank Member Posts: 4
    I have been told by the service mgr at the dealer on 8/17/99 that GMC should be coming out with a TSB fix for the 99 Sierra drivetrain vibration at the end of August. It apparently involves the replacement of the rear springs with stiffer ones that raise the rear-end a bit and change the angle between the tail of the trans. and the differential (as someone here had mentioned as a possibility before). Hopefully this will solve the problem w/o creating new ones.
  • obeardenobearden Member Posts: 34
    Have a look at topic # 654. Might need to go back 15 to 20 posts, but lots of info available
  • gl3gl3 Member Posts: 31
    I have a 99 excab silverado, 4x4, I have also
    experienced the windshield noise ( I have a Lund
    bugshield ) I also have had wind noise from the
    3rd door 1/4 window, dealer replaced the latch
    but still have noise. Currently trying to solve
    "clunk" from rearend when traveling over small
    bumps. Dealer said was spare tire,the tailgate,
    now replacing rear springs. Anyone else have this?
    Annoying as hell after spending that much money.
    Dealor has also installed "anti clunk" seal.
  • obeardenobearden Member Posts: 34
    When you hear the "clunk" sound, is it while you are re-accelerating? Is it above or below 1500 RPM and do you feel a forward jolt at the same time? If so, you probably need to have the EPROM re-flashed. The reflash addresses this and several other issues. The "clunk" is probably the torque converter locking after momentary heavy acceleration. The re-flash prevents converter lock-up below 1500 RPM. Mine hasn't done it since the reflash. More info to come....
  • obeardenobearden Member Posts: 34
    Go to this GM site http://calid.gm.com/vci/
    and enter your VIN Number. Be
    patient, it sometimes takes a while for the site to
    respond. You will get the details on all the flash
    upgrades from the past. Each upgrade includes all
    the preceeding changes. As you will see, there are
    several issues addressed in addition to the one you
    mentioned. Print the resulting page and take it to
    the dealer.

    Good Luck, it worked for me.
  • obeardenobearden Member Posts: 34
    I don't know why the link above doesn't work. It worked fine for me a week or two ago. It won't even work from my favorites. All I can say is wait a day or two and try it again.
  • gl3gl3 Member Posts: 31
    Actually it is more of a "clank", it happens
    even when "coasting" so I don't think it is the
    converter. It is a metal to metal sound under
    the rear end area. Almost sounds like a loose
    caliper but I have applied the brakes and it still
    occurs. I will suggest the two sided tape for
    the windshield to my dealer, is there any adjust-
    ment on the 1/4 window? Not much faith in my
    dealer service dept. Site still will not open
    will keep trying....thanks for info, obearden.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Sounds like gear backlash in the rear end to me. To me, I'd rather hear that, if it was occasional, than worry about not having enough backlash.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Link is dead, for now at least.
  • obeardenobearden Member Posts: 34
    Does sound like gear backlash. I was hearing some of this before the reflash, but not now. Be aware that on the new trucks, when you release the accelerator the converter does not unlock as in the past, so when you put your foot back down there is no give in the drive train. The flash keeps the converter unlocked below 1500.

    gl3--when you say coasting, do you mean you just hear the sound when you are coasting along before you re-accelerate?
  • obeardenobearden Member Posts: 34
    About your quarter window, this might help temporarily. Run you air conditioner only in the recirculate position. When you put it in the other setting, lots of outside air is introduced and this pressurizes the cab and could cause a lot more leakage and noise. But note that if you go about two click past the foot vent setting toward defrost setting, the system will overide and force the introduction of outside air.
  • gl3gl3 Member Posts: 31
    The noise occurs when going over a bump. It does
    not matter if I am in the gas or letting off.It
    can be just a small pothole or speedbump.Dealer
    says it is the springs slapping together. they
    said they tied a creeper to the bumper and pulled
    a tech around he lot. Who knows? And I have noticed that the AC settings affect the noise.
    Just seems like a pain ya know? Thanks
  • mfreemanmfreeman Member Posts: 37
    Sounds like a pretty stupid thing to do, but at least you know they are welling to risk life and limb to fix your problem.

    ... so I wonder what sounds the creeper made when it went over the bump? :)
  • gl3gl3 Member Posts: 31
    Well lets put it this way, the first time I had
    the oil changed they left the fill cap off, and
    whoever works on it must not know how to wash his
    hands as it is a black truck and always comes back
    with greasy handprints on it. So I am not real
    confident in their abilities. It goes in Wed for
    the new rear springs, cross your fingers.
  • obeardenobearden Member Posts: 34
    Keep us posted...
    And by the way. I don't buy the creeper story for a second, they were pulling your leg if they told you that.
  • gl3gl3 Member Posts: 31
    Well, picked up truck from dealership, and
    to my suprise...no noise...so far. Keep your
    fingers crossed. And it looks like they actually
    replaced the springs. My service invoice this time
    stated that they "hooked ears up to rear of truck
    to find noise" I don't believe the creeper story
    either but they actually wrote that on the last
    work order. If this indeed does fix this, I think
    I can live with the 1/4 window and W/S noise. I
    think they might need to work on the T/Converter
    though as the other day in the rain it was clunk-
    ing like hell in between shifts. I also heard
    something this morning for the first time...lifter
    chatter when I first started it..anyone else have
    that? It is the 5.3 Does it ever end? Thanks
  • gl3gl3 Member Posts: 31
    I forgot to advise that the GM website is back up
  • marcmarc Member Posts: 21
    I have the same "clank" when going over speed bumps......
    Also, sometimes when I am stopped and shift from D to R I hear a loud clank in the drive train, like bad U joints.
This discussion has been closed.