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What does the term 3/4 ton or 1/2 ton axle refer to???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 1986Blazer, Aug 7, 2002.

  1. 1986Blazer

    1986Blazer 1/2 ton status

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    Maybe this is a dumb question but what does the term "1 ton axle" or "3/4 ton axle" refer to. The axle itself does not weigh that much. Is it the weight that the axle can support like the tongue weight on the trailer ball???

    Thanks for any replies.....I just had someone ask me what it meant and I could not answer.
     
  2. HarryH3

    HarryH3 1 ton status Author

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    It's a throwback to the early days of trucks, when they were really rated as to how much cargo they could carry. A 1/2-ton was good for 1,000 lbs in the bed, a 3/4-ton was good for 1,500 lbs and a 1-ton was good for 2,000 lbs. Over the years the cargo capacities of trucks have increased, but the old 1/2, 3/4, 1-ton monikers have stuck around.

    I just hauled a 1,300 lb load to LA and back in a "half ton" Dodge pickup. The truck drove and handled fine, pulled the mountains at 70-80 mph (including across the Continental Divide at just over 11,000 feet above sea level) and ran great. So it's obviously good for more than just 1,000 lbs in the bed. /forums/images/icons/cool.gif

    But basically, as the rating increases, the beefiness of the drivetrain and suspension increase to deal with the additional abuse. That's why the 3/4-ton GM's have a 14-bolt rear, while nearly all of the half tons have a 10 or 12 bolt rear.
     
  3. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Those terms rely on the GVWR of the truck. Generally, the higher the GVWR, the higher the rating of the truck.

    Axles play an important part of determining the rating of 1/2, 3/4 or 1 ton. Suspensions also play a part in this, too.
     
  4. 79Beast

    79Beast 1/2 ton status

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    The previous replies are definately correct, but I feel that they may have left out the main ideas you were looking for. We refer to a Dana 60 front axle as "one ton" because it was standard equipment under a C/K30...which is what we call a "one ton truck". Dana 44's can be either 3/4 or 1/2 ton depending on what they came from. The only difference is that the 3/4 ton version has 8 lugs, bigger brakes (slightly bigger) and slightly bigger bearings. The ring and pinion as well as the axleshafts and Ujoints are the same. 10bolts follow suit with the Dana 44's. As for rear axles: Full floating 14 bolts were offered in both 3/4 and 1 ton trucks, with a dually version being an option for the 1 tons. Some lighter duty 3/4 tons had a semi floating 14 bolt. This semi floating axle was an option on some heavy duty half tons and is available with 6 or 8 lugs. Standard equipment on 1/2 ton trucks is either a corporate 10 bolt or 12 bolt...depending on the year of production. A few Chevy's came with Dana 60 or 70 rears, and (AS ALWAYS) there are the exceptions to the rule...GM is famous for throwing together whatever parts they had laying around.
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Dually trucks come with D70 rears.
     
  6. 70~K5

    70~K5 1/2 ton status

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    Dually trucks have come with both D70s and 14BFFs.
     
  7. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Yep, what 70~K5 said..../forums/images/icons/wink.gif
     
  8. BAD LUCK 79'

    BAD LUCK 79' 1/2 ton status

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    i have a question to add to this tread if ya'll don't mind me butting in.... how hard is it to convert a dually 14b to a standard single wheel to each side??? i've found a few up here in WV so far and was wondering if it's worth the money and effort to get one and convert it over,... thanks
     
  9. 70~K5

    70~K5 1/2 ton status

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    Just bolt on SRW wheels on it. /forums/images/icons/ooo.gif /forums/images/icons/shocked.gif /forums/images/icons/grin.gif
     
  10. blackwidowk5

    blackwidowk5 1/2 ton status

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    As long as your answering this questions, here's another along the same lines. What's the difference between a semi-floating, and free-floating axle? thanks
     
  11. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    I will assume you mean semi-floating & FULL-floating? In a SF one end of the shaft (diff side) is supported in a bearing carrying no weight, the other (wheel side) is supported in a bearing and bears the weight of the truck/car. This is because the wheel/tire is mounted directly to the end of the sfaft. The FF is the same at the diff end but at the wheel end there is a hub w/ a bearing and a flange that is mounted to the axle tube, this bears the weight and allows the outboard end of the shaft to splined insdead of having a mounting flange. By doing this the axle housing becomes the loaded member. The splines fit into the hub and allow the torque to be transfered to the wheel. The design allows niether end of the shaft to support the weight of the truck, so the shaft now "floats" on both ends.
     
  12. blackwidowk5

    blackwidowk5 1/2 ton status

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    As you can tell i no very little about them. /forums/images/icons/blush.gif . Is the Full floating a stronger axle? What are the benefits to each one? Thanks
     
  13. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    The FF is a safer design. If a shaft breaks it will no longer send power to that wheel. If a SF axle breaks the wheel will come off along w/ the part of the shaft it is mated to. The FF axles are used in higher GVW trucks so they are built to support a heaver load.
     
  14. fortcollinsram

    fortcollinsram 1/2 ton status

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    yes, the full floating design is much stronger than a semi-floating design...In the semi-floating design, the axle shaft must support the weight of the vehicle AND provide rotational forces to the wheel (in other words, it must suppor tthe vehicle and move the vehicle) In a full floating axle, the axle shaft may be smaller in diameter, but that is because the have only one purpose and that is to move the vehicle...the full-floating design relies on a par of hubs, each containing an inner and outer wheel bearing)to support the weight of the vehicle(similar to a front axle)...

    Chris
     
  15. 79Beast

    79Beast 1/2 ton status

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    As far as GM axles go: full floating axles have a bearing design similar to a front axle....there are two bearings that go between a spindle and the hub assembly. They are held on by one or more spindle nuts and support the weight of the vehicle directly. If an axleshaft breaks on a full floating axle, the tire, wheel, and brake assembly will stay on. Semi Floating axles have only one bearing (pressed into axletube) which support the weight of the vehicle via the axleshaft. The axleshaft is held into the differential with a C clip. If the C clip breaks or the axleshaft breaks, the tire, wheel, and brake assembly will fall off. Full floating designs are much stronger and will support heavier loads, mainly because of the use of two bearings versus one and the load being supported directly by the spindle instead of an axleshaft.
     
  16. 79Beast

    79Beast 1/2 ton status

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    I agree with you that the heavy duty duallies come with D70's. Far more dualies came with FF14's than D70's.
     
  17. blackwidowk5

    blackwidowk5 1/2 ton status

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    based on what you said the 12 bolt's are semi floating right? BTW, thanks for the answers it's nice knowing what everyone else means when they're talking.
     
  18. 79Beast

    79Beast 1/2 ton status

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    Yes, a GM 12 bolt is a semi floating design. You are welcome. It make me feel smart to be able to answer a question. Ask me anything you want to and I'll TRY to answer.
     
  19. bryguy00b

    bryguy00b 3/4 ton status

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    one way to tell is the hub sticks out right..instead of being flush on the end...with the wheel or somethin like that..?

    Bryan
     

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