Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Difference Between 1 Ton and 3/4 Ton 14 bolt FF Axles?!?!?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Waxer, Apr 11, 2002.

  1. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    I have read a lot of posts on this board regarding this and have compared the two and found that there is no difference between the two other than the 3/4 ton version can have either 11" or 13" drums.

    The perches are in the exact same location between the two and the shock mounts are the same. I have looked at over 2 dozen 1 Ton Trucks and 10 times that in 3/4 ton. I've measured, and measured, and then measured some more.

    Does anyone have any other data to show this to be false?

    I know the Van version 14 is wider and needs perch and shock mount relocation but thats the exception.

    I've read many posts on this board saying the 1 Ton version 14FF needs the spring perches and shock mounts relocated, which is false as far as I'm concerned.
     
  2. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    Re: Difference Between 1 Ton and 3/4 Ton 14 bolts?!?!?

    That's wierd? I had 4 - 14 bolts in my garage at once before and 2 were 3/4 and 2 were 1 ton and both the 1 tons perches needed to be moved to work with the K5's and both the 3/4 ton did not.
    The 14bolt I have under my truck currently is from a 1 ton and Yes, I had to move the perches. I know, b/c I DID IT!!
    If you looked at my 14bolt now, you can kinda see where the perches use to sit...you're right about the drums though, both the 3/4's had 11" and the 1 toners had the 13". Never had a van 14, but that's what I "Heard" too.
    Boss
     
  3. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    Re: Difference Between 1 Ton and 3/4 Ton 14 bolts?!?!?

    So are you saying that the perches on your 1 Ton were too wide? Too Narrow?

    Both my roomates got their 14's off 1 Ton's and both measure the same as my 3/4 Ton version. This coincides with the 1 Ton trucks I've seen on the road and actually measured.

    Almost got my ass kicked measuring under some guys truck. After I explained to him what I was doing, he laughed and said it was cool. Whew!!
     
  4. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    Re: Difference Between 1 Ton and 3/4 Ton 14 bolts?!?!?

    Let me clarify that I'm not saying anyone is wrong. I'm open to learning and am just expressing what I have found through my experiences.

    I'd love to find a book on the axle that explains all the differences between all the years. That would end it for me.
     
  5. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    Re: Difference Between 1 Ton and 3/4 Ton 14 bolts?!?!?

    Hmm, maybe I'm reading you wrong. The perches itself are the same width on both 3/4 and 1tonners 2.5" wide. But on the 1 tonners, they were welded too "inward" From memory, they were like ~40.5" apart (from the perch eye) and the 3/4 were like ~42.5". Had to move each perch from the 1 tonners ~1" out. I used the 3/4 tonners I had as a bases to get a general idea of where the perches on the 1 tonners had to be.

    That's funny about measuring some [censored] off some dudes truck..lol /forums/images/icons/smile.gif I caught someone doing something similar to mine before...he was checking out how I did my extended shock mounts though.... /forums/images/icons/wink.gif
    Boss
     
  6. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    Re: Difference Between 1 Ton and 3/4 Ton 14 bolts?!?!?

    Just read your "clarifying" message. I hear yah /forums/images/icons/smile.gif. I'm with yah. just explaining my experiences too. GM does some wierd [censored] from time to time, so nothing really suprises me anymore /forums/images/icons/smile.gif
    Boss
     
  7. Diesel Dan

    Diesel Dan 1/2 ton status

    Joined:
    Feb 27, 2002
    Posts:
    798
    Likes Received:
    0
    Location:
    Warren, Ohio
    IF I am correct(big if at that) the spring perchs are wider on the crew cab rear axles. I pulled a rear axle out of a 3/4ton 2wd crew cab and the pads had to be moved. Never had a problem if it came out of a reg cab, blazer or suburban. I never measured the rear axle in the 6 crew cabs that I drove but I do recall the springs being closer to the drum than others.
     
  8. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    So does this mean that the 1 Ton version trucks have their frame a bit wider than the 1/2 or 3/4 tons?

    Or do the springs bow outward some?
     
  9. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    I never paid attention to the 1 ton frames, so I'm not sure, but I think I remember "hearing" that they have their actual spring mounts and shock mounts positioned/placed a little different then the 1/2 and 3/4 tonners... Where's K30dude? I'm sure he could fill us in on how the 1 ton frames and/or spring mounts are....
    Boss
     
  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    Were all those 1 ton's 2 WD or 4WD?

    Rene
     
  11. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    Mixture of both. Didn't pay attention to which was what when I measured tho. Does that make a diff on the rear axle thats put on them?
     
  12. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,169
    Likes Received:
    1,372
    Location:
    E-town baby!
    I'm not sure.../forums/images/icons/crazy.gif it might though.

    Rene
     
  13. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    Steve, frames are the same widths. Its the rear spring hangers on the K30's that are "narrrower". This makes the springs sit inboard more and therefore the perches on the axles are narrower than the 3/4 ton's.

    The other confusion everyone makes with the brake size between 11" and 13" is not just the diameter of the drums, but the widths of the shoes.

    3/4 ton-version 14FF's use both 11" and 13" drums, but each are using 2 1/2" wide shoes. (I'm not exactly sure on the width, would need to look up in my book for the exact width)

    1 ton-version 14FF's use the 13" drums, BUT, their shoes are 3 1/2" wide. This is the big difference between the 3/4 ton 13" and 1 ton 13" drums and shoes. /forums/images/icons/wink.gif

    So, if you took a 3/4 ton and 1 ton 14FF and laid them side by side, you would definitely see the difference between the drums. One will be wider and one narrower. /forums/images/icons/wink.gif
     
  14. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    What about between a 2wd and 4wd 1Ton? Are the 14 bolts on those different at all?

    My roomates both swear that they got their 14's off 1 Ton's, yet their 14's match mine in every way and I got mine off a 3/4 ton.
     
  15. Waxer

    Waxer 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,857
    Likes Received:
    0
    Location:
    Long Beach, CA.
    Wes,

    Better yet, would you be willing to scan and post pics of the pages out of your book that shows the differences? So I can finally shut them up, once and for all. Thanks.
     
  16. 6.2Blazer

    6.2Blazer 1/2 ton status

    Joined:
    Feb 24, 2000
    Posts:
    4,675
    Likes Received:
    26
    Location:
    Ohio
    My 14-bolt FF came off of a 2wd 1-ton pickup, about an '86 model I believe. In the stock configuration the spring perches on the axle were too narrow (i.e. too close together) so they had to be cut off and repositioned further outboard on the axle to fit under my K5. I also had to move the shock mounts to match up with the factory frame end mounts.

    I'm not trying to question you or your friends, but 1-ton 4x4's don't seem to be that common in the junkyards plus a lot of people honestly don't know or can't tell the difference between a 3/4 ton and 1 ton truck. Maybe the place your friends bought the axles at told them the wrong information?
     
  17. BadDog

    BadDog SOL Staff Member Super Moderator Author

    Joined:
    Feb 24, 2001
    Posts:
    7,777
    Likes Received:
    11
    Location:
    Phoenix, AZ
    I'll also chime in with my experience. Pretty much the same thing K30Guy said. The frames are the same width between 3/4 and 1 ton. The hangers on a 1 ton SRW (don't know about DRW but I suspect the same) are narrower, that is, they set the spring closer to the frame than the 3/4 tons. At one time I wanted to do the “front hanger on the rear spring used as a rear hanger to do a shackle flip” for my K30. However, I was disappointed that there are no suitably long donors that do not set the spring out about 1” too far. I think the narrower spring mount for 1 tons is primarily to allow the dual wheels on a chassis-cab to clear. I'm quite sure that the distance between the perches is different (narrower on the 1 ton) but I've never done the investigation and measurement that you have done so I suppose I could be wrong. BTW, my K30 springs measure 37.5" between them.
     
  18. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    Ahh...there he is /forums/images/icons/smile.gif
    I knew it had something to do with the spring mounts... (ie. spring hangers.)
    Boss
     
  19. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    Man the more I read on this topic the more I get confused.....

    I am wanting to get a 14bolt FF for my 1979 K5 Blazer and I need to know where to look for them. 2wd - 4wd - 3/4 - 1 ton - crew cab - regular cab ahhh I am lost

    What has everyone come to a consensus on that WILL swap in for me with no perch mods?
     
  20. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    No perch mod, look for: 3/4 ton from 2wd or 4wd p/u or burb.
    Boss
     

Share This Page