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10 bolt to a 14bolt semi

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by jimmy'sjimmy, Feb 9, 2003.

  1. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    alright i think im might get a semi floater /forums/images/graemlins/laugh.gif what am i going to have to change to put it in? are the spring perches off and are the shock mounts off too?
     
  2. Dale fan

    Dale fan 1/2 ton status

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    I hate to but into your post but i have been looking at the same idea since my wheeling won't be to hard and I'd like to stay 6 lugs. Which ones are easy fits? I have a bunch around here from the 90's IFS trucks.
     
  3. bablazer73

    bablazer73 1/2 ton status

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    If my 87 survives the winter, It's getting a semi floater 3/4 ton axel. (swapping front also). I'm doing it just because it's cheaper than swapping gears. want 3.73's. For the most part, it's a bolt in. You have to use the blazer e-brake cables. And you might have to run a conversion u-joint or shorten the 3/4 ton driveshaft to match. Spring perches and shock mounts are in the same location. Just make sure you get the spring plates with the axel. They are different. /forums/images/graemlins/k5.gif
     
  4. CHEVY 4WD

    CHEVY 4WD 1/2 ton status

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    Does anyone know how much a 14boltSF weighs then a 10bolt?
     
  5. 98sub454

    98sub454 Registered Member

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    my uncle had an 89 2500 suburban that had the semi floater in the rear, you may want to look into those trucks as well.

    those will bolt right in too wont they??? /forums/images/graemlins/confused.gif
     
  6. Blue85

    Blue85 Troll Premium Member

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    I did this swap. Just tell me what it is you want to know...

    There are 3 main versions of this axle available.
    1) 8-lug with spring perches in the right place: found mostly under 3/4-ton subs and vans, pre-IFS only
    2) 8-lug with wider spring perches: found mostly under IFS 3/4-ton pickups. This would be the least desireable.
    3) 6-lug with wider spring perches: found under heavy-half and 3/4-ton IFS pickups.

    There were also some different brake options, but that isn't critical.

    You have two main options:
    -Get an older 8-lug and swap the drums and axleshafts to get 6-lug (this is what I did).
    -Get a newer 6-lug and have the spring perches and shock mounts moved. This should actually be cheaper, as long as you find the right shop to do the work.

    Keep in mind that the drums are very expensive: $80 or more each. 6-lug axleshafts can be had for about $100/each or you may get lucky in a junkyard. All of the 14BS/F use the larger size U-joint, so you will need work done on your driveshaft or an adapter U-joint, which is pretty much only available from NAPA.
     
  7. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    thanks guys. the axle is on ebay if u wanted to see it. its got rear discs and its 8 lug, /forums/images/graemlins/crazy.gif it looks like its a newer axle from a 3/4ton. what would be the best way to go? would it be better to just buy some 8 lug wheels or go ahead and convert it to 6 lug? also i dont see any calipers on it /forums/images/graemlins/mad.gifso i figure ill need those too. if i need calipers and i need to move the perches how much do u think all this will cost? /forums/images/graemlins/confused.gif Ebay Listing
     
  8. wrathORC

    wrathORC 1/2 ton status

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    If you're going to go 8 lug go with a full-floater. Especially when you're thinking about paying $400 for an 8 lug semi-floater.
     
  9. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    id like to stay 6lug but if i have to ill go with 8lug. bad thing is i already bid on the axle so there is no going back now /forums/images/graemlins/frown.gif
     
  10. bablazer73

    bablazer73 1/2 ton status

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    shipping isn't gonna be cheap. Can you undo your bid? It seems like that is out of a later series truck. Your gonna have to re do spring perches. It would be cheaper to get a 14ff and do disc conversion than what thats gonna take.
     
  11. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    hey blue if i just ordered some new 6lug shafts and moved the perches would that do it? ohh yeah and the u joint too. /forums/images/graemlins/confused.gif
     
  12. Blue85

    Blue85 Troll Premium Member

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    The calipers are the real score on those late-models. Somebody has already grapped them to do rear disc on something. If you don't want a parking brake, it's not a big deal, but if you do, you will have to come up with some expensive calipers.
     
  13. Blue85

    Blue85 Troll Premium Member

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    You also will need new 6-lug drums. Otherwise, though, it's pretty much that easy. All of the axleshafts will fit in all of the housings, but there are some differences in lengths to match up with the different drums. So you have to get shafts and drums to match.
     
  14. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    hey blue i got a hold of the seller and he says it comes complete with calipers and new pads /forums/images/graemlins/thumb.gif.on the off-road.com site someone showed me a set of adapters from 8lug-6lug but they r $200 /forums/images/graemlins/shocked.gif but i think that would be cheaper than changing the axles.
     
  15. Blue85

    Blue85 Troll Premium Member

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    I looked into those 8-6 lug adapters for a while, thinking that then any old SF or FF 14-bolt would just drop right in. I contacted several vendors of wheel adapters, but when it came down to it, nobody was comfortable with a design for this and most told me it was impossible.

    You should check out the width, though. If the axle you get has the same width as your existing one, then the spacers may give you the ideal rear width. For some reason my rear axle is almost as wide as my front, which I like. You generally need 1.5" on each side to make a GM rear match the front. Many peopl are afraid of spacers like this. I know that it is important to torque them right and keep the torque right.
     
  16. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    the new axle wheel mounting surface is 68.5". i emailed the seller of those adapters and he said nope they dont fit the S/F, so i guess im going with the new shafts. do they make 15" 8lug wheels? the only ones i could find r 16" but my tires are R15 /forums/images/graemlins/frown.gif
     
  17. jimmy'sjimmy

    jimmy'sjimmy 1/2 ton status

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    just makin sure, will a pair of axle shafts say from hill 4 wheel drive for a 14 S/F fit my axle? Im going to go ahead and get the ebay one and change the shafts to 6 lug.
     
  18. Blue85

    Blue85 Troll Premium Member

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    It is strange that the adapter doesn't fit the 14B S/F. What in the world does it fit, then? Of course it wouldn't fit the F/F, but the whole purpose of the 8lug-6lug adapters is for the situation that you are in. Maybe there is some miscommunication or they are just not the wheel adapters that we are both thinking of.

    There are 8 lug 15" wheels. They are hard to find and come with their own set of problems. I think Eaton makes one. Don't expect to get the particular style you like. They only come in steel, since the alloy ones are too thick. They fit on nearly every 8-lug rearend with drum brakes. The problem is the front end and rear ends with disc brakes. You are pretty much into a world of strange offset wheels, wheel spacers or caliper grinding. There are plenty of threads on this topic if you search.

    That is actually one of the reasons that I stayed 6-lug. I wanted to run 15" wheels for the selection and prices of 15" wheels and tires. I also wanted aluminum. So for me it was the right choice. You need to weigh out all of the pros and cons and prices for yourself. It may be that swapping on 8-lug outers on your front end and buying new wheels is cheaper than changing an 8-lug rear over to 6-lug. Remember, too, that you can always get some money back by selling your existing wheels and tires. People like to buy complete sets ready to bolt on. Plus, when you buy new wheels and tires, it is always cheapest to buy everything together at once. There have also been a number of threads on this topic.

    68.5" is pretty wide. The 10-bolt front should be about 67", although the 3/4-tons were maybe 69". I am not sure about those numbers, but I am almost certain that 68.5" is significantly wider than what you have back there right now. This may be the same width that I am running. If you swap axleshafts, make sure you know the length, because there are different ones available. They will all physically work in that axle, but it changes how the backing plate for the brake should line up and the rear track width.
     

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