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.

Educate me on D60 and D70 Rears

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 350350, Oct 29, 2003.

  1. 350350

    350350 1/2 ton status

    Joined:
    Sep 25, 2003
    Posts:
    939
    Likes Received:
    0
    Location:
    USA
    What little I know about the D70 is that it was a dually thing and is basically a D60 with larger axles???

    Is this true?

    /forums/images/graemlins/1zhelp.gif What are the differences between the D60 and D70?

    /forums/images/graemlins/1zhelp.gif Is the dually rear the same width as a single rear wheel rig? (And therefore a straight bolt-in for my '77 K5?

    /forums/images/graemlins/1zhelp.gif It seems like I hear a lot more about using the 14FF rear for 1-ton swaps and not much about the D70. Why?

    Thanks!

    Paul 'X'
     
  2. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

    Joined:
    May 19, 2001
    Posts:
    45,032
    Likes Received:
    369
    Location:
    Vancouver, WA, USA
    [ QUOTE ]
    What little I know about the D70 is that it was a dually thing and is basically a D60 with larger axles???

    Is this true?

    [/ QUOTE ]

    not really...D70s dont have to be dualies and the 70 is a completely different axle than the 60.

    [ QUOTE ]
    /forums/images/graemlins/1zhelp.gif What are the differences between the D60 and D70?

    [/ QUOTE ]

    D70 is much beefier... specs...

    D70 max load, 6000lbs,
    max Torque short duration=8000 Lbs.Ft, Continuos= 2000 Lbs.Ft.
    Ring Gear Dia= 10.500",
    tooth width 1.000",
    Tube Dia 3.562" ,
    Side gear spline24/48 pitch,35T 1.458 P.D.
    weight center section=150lbs

    D60 specs...

    max load, 5500lbs,
    max Torque short duration=5550 Lbs.Ft, Continuos= 1500 Lbs.Ft.
    Ring Gear Dia=9.750",
    tooth width 1.4370",
    Tube Dia 3.125"
    Side gear spline24/48 pitch,30T 1.250 P.D.
    weight center section = 120lbs.

    on the left is a D70 shaft, on the right a ffd60 rear shaft...

    70 vs 60

    [ QUOTE ]
    /forums/images/graemlins/1zhelp.gif It seems like I hear a lot more about using the 14FF rear for 1-ton swaps and not much about the D70. Why?

    [/ QUOTE ]

    prolly cause they are dirt cheap bolt-in swaps for our rigs. Only advantage that I know of in the 70s favor over the ff14b is that you can get gears down to like 7.17 or some crap for the 70 while the ff14b can only go down to 5.13. Since most of us have no need for gears below 5.13 in the diffs, the ff14b is the best choice.

    j
     
  3. reeser

    reeser 1/2 ton status

    Joined:
    Oct 8, 2001
    Posts:
    434
    Likes Received:
    0
    Location:
    Hayden Lake, ID
    no, dually spring perches will not 'bolt up' to your k5. like J said the 70's are way way beefier than the 60's. the reason so many k5 guys run 14 bolts is because 100% of 3/4 ton trucks came with 14 bolts and they bolt directly into your k5 with a 1/2 ton 3/4 ton conversion u joint. also about 90% of 1 ton trucks from gm came with the 14 bolt. 70's and 14 bolts have about equal amount of beef but the 70 has 35 spline shafts and the 14 bolt has 30 spline shafts.
     
  4. 350350

    350350 1/2 ton status

    Joined:
    Sep 25, 2003
    Posts:
    939
    Likes Received:
    0
    Location:
    USA
    [ QUOTE ]
    not really...D70s dont have to be dualies and the 70 is a completely different axle than the 60.

    [/ QUOTE ]

    So will a 1-ton NON-Dually D70 bolt into the K5???
     
  5. 350350

    350350 1/2 ton status

    Joined:
    Sep 25, 2003
    Posts:
    939
    Likes Received:
    0
    Location:
    USA
    [ QUOTE ]
    Only advantage that I know of in the 70s favor over the ff14b is that you can get gears down to like 7.17 or some crap for the 70...

    [/ QUOTE ]

    /forums/images/graemlins/thinking.gif 7.17... /forums/images/graemlins/thinking.gif I guess if you never needed to go more than 30mph it would be pretty cool!

    /forums/images/graemlins/eek.gif Or like 15mph in lo-range! /forums/images/graemlins/eek.gif

    Paul 'X'
     
  6. azblazor

    azblazor 1/2 ton status Premium Member

    Joined:
    May 5, 2001
    Posts:
    1,953
    Likes Received:
    0
    Location:
    Arizona, Phoenix area
    I believe that you can put hummer rims on the D70 P/U dually axle and have a close match (track width) to a front chevy dually D60 with hummer rims. This is the reason for some of their popularity.
     
  7. 350350

    350350 1/2 ton status

    Joined:
    Sep 25, 2003
    Posts:
    939
    Likes Received:
    0
    Location:
    USA
    [ QUOTE ]
    no, dually spring perches will not 'bolt up' to your k5.

    [/ QUOTE ]

    So do the NON-Dually D70 spring perches match a K5???

    [ QUOTE ]
    like J said the 70's are way way beefier than the 60's. the reason so many k5 guys run 14 bolts is because 100% of 3/4 ton trucks came with 14 bolts and they bolt directly into your k5 with a 1/2 ton 3/4 ton conversion u joint. also about 90% of 1 ton trucks from gm came with the 14 bolt. 70's and 14 bolts have about equal amount of beef but the 70 has 35 spline shafts and the 14 bolt has 30 spline shafts.

    [/ QUOTE ]

    So it sounds like it's an easier 'find' to do a 14BFF, but is there any reason I *wouldn't* want to do a D70 if I got a 'steal' on one? Like say, is the 14BFF cheaper/better than the D70 for:

    /forums/images/graemlins/cool.gif Disc Brake Conversion?
    /forums/images/graemlins/cool.gif Cost of a Locker?
    /forums/images/graemlins/cool.gif Ground Clearance for the Pumpkin?

    Thanks!
     
  8. K5DRAGER

    K5DRAGER 1/2 ton status

    Joined:
    Jul 27, 2001
    Posts:
    1,164
    Likes Received:
    0
    Location:
    Momence, IL
    A non dually dana 70 will bolt into a Blazer if you move the spring perches and shock mounts. Just make sure you cross reference the bom numbers so you know what it came out of especially before you buy gears or parts for it . The most desireable ones had 35 spline shafts. But there was also 32 and 16 spline versions. I have one out of a late 70's dodge in my Blazer with welded dif, 5.86 gears and disc brakes.
     
  9. K5DRAGER

    K5DRAGER 1/2 ton status

    Joined:
    Jul 27, 2001
    Posts:
    1,164
    Likes Received:
    0
    Location:
    Momence, IL
    14 bolt will be easier to do a disc brake conversion since alot of people make them. And the detroit locker for a 14 bolt is alot cheaper than for a D70.
     
  10. SUBFAN

    SUBFAN 1/2 ton status

    Joined:
    Mar 23, 2003
    Posts:
    2,334
    Likes Received:
    0
    Location:
    Davenport, Ia
    What he said, BUT, a D70 gives you more choices. There are more gears available, along with more lockers. A D70 is a bit more expensive to build, but if you get one for a steal, I would go for it, or send it to someone looking for one to help finance your 14FF.

    I have a 60 rear that is just waiting to be installed, and if I found a 70 for the right price I would use that instead....
     
  11. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

    Joined:
    May 19, 2001
    Posts:
    45,032
    Likes Received:
    369
    Location:
    Vancouver, WA, USA
    yeah, nutting wrong with a D70 at all. In fact, it'd rock to have a D70HD in a k5 if for no other reason than for something to talk to wheelin buddies about. /forums/images/graemlins/wink.gif

    chevy has use D70s in the past... so there might be some out there that are single wheel and have the right spring perch width... I really dunno. As others stated... the 70 has better selections of lockers/lim slips etc.. but the detroit for a ff14 is dirt cheap.

    i think the bottom line is, if you want to run gears 5.13 and lower (numerically) and to run either open diff, detroit or welded..go with the ff14b. If you want higher gears or a locker/lim slip that isnt offered for the ff14b or just "something different" in ur rig, go for the D70.

    j
     
  12. BowtieRed

    BowtieRed 1/2 ton status Author

    Joined:
    Dec 31, 2002
    Posts:
    1,776
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    anything over 5.89 is useless IMO as the pinion is about the size of my. . . pinkie. . . . and tends to be real weak.
     
  13. 84_Chevy_K10

    84_Chevy_K10 Banned

    Joined:
    May 30, 2001
    Posts:
    17,669
    Likes Received:
    0
    Location:
    IL, USA
    Nothing about an axle with that big of gears is weak. Weaker, maybe, but weak, no.
     
  14. bigjohnintexas

    bigjohnintexas Registered Member

    Joined:
    Oct 17, 2003
    Posts:
    17
    Likes Received:
    0
    Location:
    East Texas
    I recently looked into swapping in a D70 for my 14FF because I really want to run a selectable locker in the rear. As everyone has said, the 14FF is dirt cheap, easy to convert to Disc, and a very solid axle. I did some investigating and decided to call ARB in Seattle. The guy straight up told me that ARB is working in an air locker for the 14FF which could be out as soon as next summer. With that in mind, I decided to hold off for a while.

    I know I didn't answer any questions about the D70 here, but I thought someone might like to know there could be a selectable locker in the near future for the 14FF, especially if that is a consideration for their choice between the two.
     
  15. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

    Joined:
    May 19, 2001
    Posts:
    45,032
    Likes Received:
    369
    Location:
    Vancouver, WA, USA
    yeah well.. I'll believe it when i see it. ARB has been sayin the ff14b locker is "on the way!" for how long now? its over a year for sure... prolly closer to 2. Not saying it won't happen... just that I wouldnt hold my breath.

    Im still tryin to figure out why anyone would want a selectable locker in the rear... especially at 2.5x the cost of the classic detroit. i guess if I lived somewhere where it actually snowed in the winter i might ponder the idea...

    j
     
  16. boz42

    boz42 1/2 ton status GMOTM Winner

    Joined:
    Jun 3, 2003
    Posts:
    3,181
    Likes Received:
    0
    Location:
    Hopewell, Tn 38058
    i run a 35 spline D70U from a 91 dodge cummins truck. i just like to be different & i prefer Dana axles over corperate ones.

    most every one here has covered all the bases. i will add this the differance between my unshaved 14ff & my 70-u is a 1.5" difference to the D70's advantage.

    also stated ealier, there are different versions. they are 70-HD, 70-u, & D-70. HD, & U are more desirable, but as long as the axle u find has 35 spline it is a good one.
     
  17. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    [ QUOTE ]
    The guy straight up told me that ARB is working in an air locker for the 14FF which could be out as soon as next summer.

    [/ QUOTE ]

    Don't hold your breath. ARB has been quoting that for the past 3 or 4 years now and still have not gotten one on the shelf yet. /forums/images/graemlins/tongue.gif /forums/images/graemlins/rolleyes.gif
     
  18. i8yrsuv

    i8yrsuv 1/2 ton status

    Joined:
    Aug 31, 2003
    Posts:
    327
    Likes Received:
    0
    Location:
    Santa Rosa,NOR KAL-IFORNIIA
    How about the locker from www.killeraxles.com ....Its SUPPOSE to be available real soon...I think its cable activated ??? /forums/images/graemlins/eek.gif Glyn
     
  19. bigjbear

    bigjbear 1 ton status Staff Member Moderator

    Joined:
    Feb 18, 2000
    Posts:
    13,973
    Likes Received:
    454
    Location:
    Marietta GA
    Ah yes the the mad toaster. At least they have one in testing, but they have also missed their release date. ARB for a FF14B? They have been saying they have one on the way since at least '98 (that was the 1st time I checked).
    Someone mentioned that "all 3/4 tons had the 14B" While this is true, it is a bit missleading. Many of the 3/4 tons had the SF14B w/ a 9.5" ring gear, not the FF w/ the 10.5" ring gear. One more tidbit, ARB does make a locker for the SF14B.
     
  20. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

    Joined:
    May 19, 2001
    Posts:
    45,032
    Likes Received:
    369
    Location:
    Vancouver, WA, USA
    [ QUOTE ]
    One more tidbit, ARB does make a locker for the SF14B.

    [/ QUOTE ]

    damn, u can only wonder what idiot over at arb thought it was a good idea to spend time developing a sf14b diff when they could have been making one for the ff14b. The ff may not be in all 3/4 tons... but it is common as hell and you see them in all kinds of rigs these days... even lame heeps!

    imo arb totally dropped the ball and chit the bed on this one. I wouldnt buy their locker anyway, but lots of peeps would...

    j
     

Share This Page