1999 GMC 3500 Dually wheel spacers... why?

Discussion in 'GMC Truck Forum' started by dennymd, Dec 29, 2009.

  1. dennymd

    dennymd Member

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    My 1999 GMC CC 2x4 Dually has what appears to be wheel spacers on the outside of the steel wheels front and rear, why? I do not see any rationale for them and there is no explanation in the users manual for them. It doe not reference them. I had stainless simulators and when I took them off, because they were squeaking when the wheels rolled and found these 3/8 to 1/2 inch spacers. They are still on there but do not know why. If you know could you please repsond back as to why. Thanks, new to this forum and believe there are probably many experts here that can answer my question. I have a few more that I will post later. :help:
    Denny
     
  2. Crmzendrgone

    Crmzendrgone Senior Member

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    I would think for spacing of the dual wheels in back?
     
  3. dennymd

    dennymd Member

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    One would think that they are for spacing the rear dual wheels, except the spacers are on the outside of the wheels in the rear, not between them. There are also wheel spacers on the front wheels on the outside too. I cannot figure out what purpose they serve. This is my question. I am the second owner of this truck and as far as I know these spacers came on the truck from the factory this way. Will await more responses. Thanks for your response.
    Denny
     
  4. Crmzendrgone

    Crmzendrgone Senior Member

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    No problem I must have mis read your post.I know some will be along that know more than I.
     
  5. stumpuller454

    stumpuller454 Well-Known Member

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    the rings are supposed to go on the outside of the wheel, the nuts hold it against the rim. they are like that from the factory. its because the OEM steel dual wheels aren`t "pitched" to the lug nuts, the rings have been cut to accept the rings, it you have aftermarket wheels these are not neccesary.
     
  6. scavanger

    scavanger Full Member

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    Are they reinforcment for the wheels? The weakest point on wheels is where they bolt on .

    Scav.
    :)
     
  7. BernieB

    BernieB Senior Member

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    With a dually the wheels get reversed for the outside rears. Because of this, and to avoid having specific inner and outer rims (this way one rim fits every position) there are no reinforced ridges around the lug holes, with an internal bevel to mate up with the bevel on the lug nuts. Instead, the steel plates that fit over the rims have these, and are required for the lug nuts to actually hold the wheels on. :)
     
  8. dennymd

    dennymd Member

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    Thanks guys, it makes sense now. I never took in the fact that the wheel gets reversed from front to rear, since they are the same wheel only reversed. If they flared the steel to accept the lug on both sides there would not be enough steel left to hold the heavy loads. Again thanks.
     
  9. BernieB

    BernieB Senior Member

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    No problem Denny. I have a '99 3500 dually too, 'cept mine is a diesel.
     
  10. Crmzendrgone

    Crmzendrgone Senior Member

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    Feels good to know that there are plenty of knowledgeable people on here.
     

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