1965-75 GM Corporate Rear

Discussion in 'Trucks and Trailers' started by streetrodjim, Oct 13, 2000.

  1. streetrodjim

    streetrodjim LawnSite Member
    Messages: 4

    I'm looking for a 1965-75 GM corporate rear for a 3/4 to 1-ton truck. These are also known as a "GM Pig" or "GM 10-bolt Truck Rear". Single or dual wheel is not important.

    Third member should have 411 or 393 gears. The third member drops out of the front of the housing like a Ford 9". The housing has a round center section. Some have a rear cover and others are part of the housing.

    Willing to pay $50 to $100 reward if you find one and I purchase it.
  2. Chuck Smith

    Chuck Smith LawnSite Senior Member
    Messages: 849


    Never heard of such an axle. Only the GM 14 bolt. When we refer to a GM 10 bolt here, it's the wimpy one.
    I know from 73 on, the 3/4 ton models used the GM 14 bolt.
    I guess you learn something new everyday. Has anyone here ever heard of this axle Jim is talking about? I don't mean does anyone have one, but has anyone even heard of one?
    I know some of the 67 - 72 models used an Eaton rear axle. Like this one here.

    <img src="http://www.chuckschevytruckpages.com/images/brettaxle.jpg">

    The diff is a full floater and approx 13 inches across. This belongs to a guy with a 71 Chevy, who lives in Austrailia. It's got 10 bolts, but he was told it was an Eaton axle. Is this what you are referring to? Is it in fact a "GM pig"? His has single rear wheels. He is having a VERY hard time getting parts for it in Austrailia.

    I'm at a total loss otherwise!

  3. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    I too,am baffled.I have never heard of one fo them either,I think maybe he's reffering to the wimpy 10 bolt 8.5?It certainly wouldnt be under a ton or 3/4 though.I thnk he wants a full floating 10.5" 14 bolt,with a locker-he just doesnt know it yet LOL.Street rod Jim-is the rear your looking for a 5,6 or 8 lug?What size brakesare on it?there are different widths of truck rears,depending on if it came from a pickup or cab &chassis-which one are you looking for?what size is the ring gear on this unit?Since i dont think you know what rear your talking about,being more specifc-we can tell you which one you need and what its proper name is.
  4. Chuck Smith

    Chuck Smith LawnSite Senior Member
    Messages: 849

    The part that loses me is the "third member". I didn't know GM ever made a 3rd member rear.
    Though, looking in my 77 GM Light Duty service manual, they do show a 3rd member type. It has a 12 1/4" ring gear. BUT, it says it has an 11,000 lb. capacity. I know the 14 bolt is rated at 7,000 lbs. I've seen the 12 1/4" in the manual before, but figured it was for step vans, and possibly C/60 models and motorhomes. I sure haven't seen it in a pick up. In fact, I've never seen one, so you will have a really hard time finding one.
    Maybe in Hemmings Motor News you'll have more luck? I doubt you'll have any luck in this forum with an axle like that.
    You might want to look in classifieds that cater to larger trucks and motorhomes. Maybe it's in C/50's C/60's C/70's and motorhomes. Oh, and it's also a single speed differential. So if you see "split rear" in an ad, it's not what you want.


    BUSHMASTER LawnSite Senior Member
    Messages: 519

    maybe youre looking for a dana 40 or 60 ...my 67 has a 12 bolt rear loaded. chevy did use dana rear end in some 3/4 and one ton truck very common espeeliy on dual wheel set ups
  6. thelawnguy

    thelawnguy LawnSite Silver Member
    Messages: 2,411

    Probably referring to the Rockwell axles found in some dual wheel apps.
  7. 84'GMC4x4

    84'GMC4x4 LawnSite Member
    from MA
    Messages: 84

    not sure where your located jim, but i found this ad in my local want advertiser,

    from full sz Blazer. Basket cases. Gd for rebuild. Rear nds new gears but shafts are OK.
    $150/bo for all; Call Paul. (Manchester, NH) 603-647-9369 n

    ...says 1/2 ton but who knows maybe its the same

  8. Chuck Smith

    Chuck Smith LawnSite Senior Member
    Messages: 849

    Nope, those are the 8.5" ring gear axles. He's talking MUCH bigger. Who knows, it may be the 12.5" ring gear shown in my factory service manual.

  9. streetrodjim

    streetrodjim LawnSite Member
    Messages: 4

    Chuck has a picture of the rear I have. I'm in northeast US,around here there called stump pulling rears, I,m told GM used them with 3.73 and 4.10 gears in camper specials, there were 3 different carrier's produced, only 1 of these will accept the 3.73 and 4.10 gears

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