9 3/8" rear differences

Discussion in 'A boatload of fun' started by quicksabre, Apr 22, 2005.

  1. bob k. mando

    bob k. mando Guest

    that's a typo and should read '71-76'. check the other sticky rear end info thread for interchange information with the 8 1/2" ring gear pumpkin.

    you probably need to verify your rear end size as well. my 76 electra has an 8 7/8" in it. you can't get aftermarket ring and pinion sets for either the 9 3/8s or 8 7/8s.
  2. pontchief

    pontchief Norwegian car nut.

    Whats the easiest way to identify either its the 9 3/8s or 8 7/8s.

    thanks :)
  3. Chris Robertson

    Chris Robertson Well-Known Member

    what can I do for my 70 wildcat? How do I get a posi and 3:42 gears?
  4. telriv

    telriv Well-Known Member

    Learn how identify one & then scour the yards or pay through the nose from e-bay.

    Tom T.
  5. SharpSabre455

    SharpSabre455 Sloan says "It's Rare!"


    I agree with Tom T. I found mine in a yard and it took a LONG time. Finding parts for these cars is not as easy as finding parts for a Lark or GS. You just have to keep looking.

  6. bob k. mando

    bob k. mando Guest

    Whats the easiest way to identify either its the 9 3/8s or 8 7/8s.

    sorry Per, i totally missed that you had asked me another question.

    i should be heading back down to Florida after the first of the year and once there i'll have access to my pictures and the various rears again. i'll get that info reposted.
  7. pontchief

    pontchief Norwegian car nut.

    Thanks Bobkmando. :TU:

    I am looking forward to see the pictures.

    Happy new year from me up in North Norway.

    Per Arne :)
  8. bob k. mando

    bob k. mando Guest

    hope this helps, between having to back up to fit the entire assembly in the frame and the low resolution allowed by the board you can't see much.

    the 9 3/8" is the 12 bolt cover housing at the top.

    the 8 1/2" is the 10 bolt cover housing on the bottom.

    the 8 7/8" is also a 10 bolt cover.

    i got the 8 7/8" out of ( in fact, we put it back IN ) a 1976 Electra. the 9 3/8" was out of a 1971 Electra. the provenance of the 8 1/2" is unknown but it was a bolt in replacement to the 71 Electra.

    Attached Files:

  9. pontchief

    pontchief Norwegian car nut.

    Thanks for the info Bobkmando. :TU:
    I am going to figure what I have, when I get the car home, probably sometime early in February.
    And it will be interesting to check out how it behaves on snowy and icy roads over here, to see if I need a posi or not.
    I used a 74 Impala as my driver last winter and I had no problems to get around with it and it didnt have a posi.
    But since these cars are heavy, I suppose that helps a lot.
    Here are picture of the Impala, not any car to drive around with if you want to be anonymous. :laugh:
    It was painted like this when I bought it.

  10. MnOlds

    MnOlds Member

    Greetings to the posters on this thread. It looks like there is a lot of knowledge here. Perhaps you can help ID the rear end I an tring to sell.
    Here's the link to the post, and a pic.



    Attached Files:

  11. pyro225

    pyro225 Heres to fireworks safety

    (posted earlier by jamyers)

    '67 to '70 Riv: One UCA and a panhard rod, L & R carrier brngs different
    '67 to '70 E/L/W: 2 UCA and no panhard rod, L & R carrier brngs different

    I've only seen up close the posi rear end on a 70 Wildcat - the housing and the mounts looked exactly like my 69 Electra's peg-leg. Is there any difference in the axle housings between Riv's and E/L/W's? Can I take a Riv posi and swap it into an E/L/W? Can I just swap the posi differential into any 67-70 open housing? Would I need the axles also or could I use the ones from the open housing? Let's say I get lucky and happen to find posi in a local yard. What is the best way to "field test" (i.e. it is a functional posi unit, the clutches are in good shape, etc.) before I buy the thing? I'm a still a little too cloudy to start scouring - any help is appreciated.
  12. jamyers

    jamyers 2 gallons of fun

    I finally got around to digging out and posting the codes from my '71 Chassis Manual on rear ends for a thread in the "For Sale" section, so I'll post it here as well so it doesn't get lost.

    The first digit indicates the axle type:
    L=A-body 8.5
    N=B-body 8.5
    Q=B & C -body 9 3/8

    the second indicates the ratio, and A-bodies had these:
    K=2.56 open
    T=2.56 posi
    L=2.73 open
    O=2.73 posi
    A=3.08 open
    S=3.08 posi
    H=3.42 open
    W=3.42 posi

    B-bodies (LeSabres) with 350 engines (and wider 8.5 axles) had these:
    A=3.08 open
    P=3.08 posi
    H=3.42 open
    S=3.42 posi
    K=2.73 open
    T=2.73 posi

    B-bodies (LeSabres) with 455 engines, and C-bodies (except Estate Wagons) had 9 3/8" ring gear axles with these codes:
    P=2.73 open
    S=2.73 posi
    I=2.93 open
    J=2.93 posi
    T=3.42 open
    A=3.42 posi

    C-Body Estate Wagons had leaf spring 9 3/8" ring gear axles.
    E=2.93 open
    L=2.93 posi
    H=3.42 open
    M=3.42 posi
    I=2.93 open

    And the third indicates the axle manufacturer
    K=GM Canada
  13. jamyers

    jamyers 2 gallons of fun

    Pyro225, I don't know for sure, I was just summarizing info from other threads. But if I recall, the Riv rear end was different, so you can't swap the whole housings.

    But you can swap the internals within "generations" of axles.
  14. 66BuickLeSabre

    66BuickLeSabre Well-Known Member

    Pretty informative thread, wish i understood it a bit more to be honest with you guys...Im taking my car out today for the first time in a few years, and I love it, dont get me wrong, really have missed this car to the point that I cant sleep tonight...but the thing that kills me about it, is the highway gears it has in it, absolutely kills it to me sometimes...its got the power but not the acceleration..

    That being said I coincidentally have a rear end out of a 70 chevelle which I know I cant use, but its got new 4.11 gears in it....is there anyway I can use these gears somehow in my rear? If not what can I do about this gear situation...Id like to move to atleast a 3.42 but more preferebly a 3.73-4.11

    Car is a 66 LeSabre w/ 340....any help is appreciated.
  15. bob k. mando

    bob k. mando Guest

    i'm sure somebody will chime in to tell you what you actually have.

    if you happen to have one of the rear's with no aftermarket support you could always swap in a 5 speed manual trans .... :3gears:
  16. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    If you (somehow) make the 4.11's work with your car, you will HATE the car on the highway....same with the 3.73's.
  17. bob k. mando

    bob k. mando Guest

    If you (somehow) make the 4.11's work with your car, you will HATE the car on the highway....same with the 3.73's.

    not if he installs a 5 speed manual transmission! :TU:
  18. lapham3@aol.com

    lapham3@aol.com Well-Known Member

    Your LeSabre has rhe smaller Skylark gears-not the 9 3/8
  19. bob k. mando

    bob k. mando Guest

    so what is that? that's before the 8 1/2" rear, yes? so it's 8 1/4"?
  20. oPh

    oPh Well-Known Member


    Your '66 LeSabre with a 340 will have a Buick cast 8.2 housing with '64-69 Pontiac 8.2 gears inside. Desiring your rear to have a posi, & say it now has 2.93, 3.08, or 3.23 gears, either search for a good mid ratio 4 pinion Pontiac Safe-T-Track carrier, or ck out what Eaton & Auburn offer in a mid ratio Pontiac 8.2 carrier. Wanting lower gear ratio, than a 3.23, will need to find nice used 3.36's or buy new 3.55's & go with a low ratio carrier. While the Chevelle 12 bolt won't fit in the LeSabre, shouldn't be too hard to find a buyer for it, & that should help go a long way to getting the ratio & posi of your choice under your LeSabre. Last, if you're planning on throwing 450 ft lbs or more of torque at the LeSabre's 8.2, you'll e better off going with a stronger rearend to build up.

    Got Posi?

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