9 3/8" rear differences

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

  1. speed70

    speed70 Henderson Driveline, Grafton OH

    Just some stuff you may or may not find interesting after i popped the cover off a 68 Electra POSI rear diff.
    #'s stamped into RG: 1385323 39-14 GMC 54 (in yellow paint)
    cast into right side of carrier: ED 02120 D 260
    left side cast between webbing: 120 2
    left side RG mounting flange of carrier: L 12 H
    Left main cap also wider than the right side.
    I'll see if i can get some pics up of this 2.78 geared POSI rear.

    Attached Files:

  2. 71GSX455-4SPD

    71GSX455-4SPD Nick Serwo Magic Car

    Hey Dave-

    Wondering if you're still running this same set-up and if it's holding up on both the street and strip. If so, do you know what part numbers the Auburn parts are and if they are available new? I have a posi rear, but when the back end is up with one person holding a tire the other can be turned fairly freely, so I assume the clutches are shot. Seems like you've found a good, simple, and inexpensive solution, just hoping it's still working well.
  3. quicksabre

    quicksabre Well-Known Member

    Ken, it still seems to be holding up quite well. I change tires with both of them off of the ground, and it doesn't even slip when I torque down the lugnuts. That S-spring deal hardly provides any preload at all.
    The plates and springs came out of the old factory installed 8.5" Auburn posi(which was replaced with an Eaton posi) that was in my '96 9C1 Caprice. So I assume it is the Auburn Gear Spring Retainer Service Kit 541018, by looking at their catalog. 541019 could be the same plates with even higher pressure springs, it's for the Pro Series 8.5" posi. But since my parts came from an OEM application, I'm pretty sure it was the standard model. No mods required, they fit right in as long as you can compress the springs down enough.
  4. 71GSX455-4SPD

    71GSX455-4SPD Nick Serwo Magic Car

    Thanks for the update, Dave, I appreciate it. Glad it's still holding up for you. I think I may make the same upgrade before I install the posi. :TU:
  5. EEE

    EEE Straight out of lo-cash!

    Anyone knows if a 66 LeSabre comes with the 9 3/8, or does that have a smaller diameter differential?
  6. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    I would imagine that it comes with the smaller rear, as the 66 LeSabre wasn't offered with the "big engine". Although, I have no idea what would be in a 66 LeSabre to begin with:Do No:
  7. DaWildcat

    DaWildcat Platinum Level Contributor

    I do know that the '67 LeSabre is NOT a 9-3/8", but someone with a '66 chassis manual will have to chime in.

  8. 76WAGON

    76WAGON Member

    Just found V8BUICK site. This is my first try.

    Need info for my 76 Buick Estate Wagon. Setting it up to tow a Travel Trailer.

    Engine was set up with RV cam, flat top pistons, .030 over, engine oil cooler remote oil filter, 4 core radiator, additional electrial fans and 2-1/4" dual exhaust.

    Power is sent thru a 700R4 transmission with an oil cooler and remote filter. The better gearing helps. Still difficult to climb hills in 3rd. Can't make full use of the 4th gear OD on the flat.

    Installed a 1972 Buick Estate Wagon 12 bolt, 9.375 ring gear differential with 2.93 gears. Original diff was a 10 bolt 2.93 gears but the axle bearings were going. The 72 housing, brakes and bearings are massive. Installed brake shoes. wheel cylinders, lines, axle bearings and seals. Scales show 3760# on the rear wheels with TT hitched up with stabilizer bars. Want to keep it.

    Need info on 9.375, 3.23 and 3.42 gears, or better. that wil fit. Willing to buy the entire differential for the carrier if needed.

  9. bob k. mando

    bob k. mando Guest

    you should start a new thread in the "Parts Wanted" section.
  10. monzaz

    monzaz Jim

    Does any one know the length of the uppoer control arm length from bolt hole center to bolt hole center and maybe a pictures of one would be great. Thanks, jim
  11. bob k. mando

    bob k. mando Guest

    sorry i took so long, Jim.

    here you go:


    arm is 11" from center to center. it's 2 7/8" wide on the inside of the wide end, 1 3/16" wide at the end that gets the bushing. 3 1/2" tall on the bushing end, 2 3/4" tall at the wide end.
  12. bob k. mando

    bob k. mando Guest

  13. funkyman

    funkyman Well-Known Member

    How many bolts on the Non Posi 67 Riviera carrier that bolt on the ring gear.Anyone know the standars rear end config.Can i put a Posi in it or is a conversion doable like a 70-76 Impala complete rear end conversion.Baiscally i want my standard 67 Riviera rear end to be a Posi.Using same or different gears.
  14. DaWildcat

    DaWildcat Platinum Level Contributor

    I know of nothing that will work short of either finding a '67-'70 posi carrier, or having a complete custom rear end assembly fabricated using a more modern & popular center section.

  15. funkyman

    funkyman Well-Known Member

    Any ideas with brand new complete rear end assembley that will fit my 67 Riv.E.g Moser engineering.Any rear ends that fit a 67-68 Riviera?
  16. DaWildcat

    DaWildcat Platinum Level Contributor

    No, there are no aftermarket assemblies "off the shelf". It would have to be built for you, probably using your existing housing as a guide and possibly parts donor.

    You have to realize that your Riv rear housing is very much an oddball because of the X frame. You have two lower trailing arms, only one upper plus a panhard bar.

  17. funkyman

    funkyman Well-Known Member

    You know this is all way too much information, or sophisticated for me to fathom all at once.All i want is a Posi rear on my 67 Riviera.What do i need for heaven sakes.Someone selling a 66-70 rear posi? and will my gears fit?.Tell me what i need and i`ll go and seek it.I need help.:Brow:
  18. DaWildcat

    DaWildcat Platinum Level Contributor

    First you need to know exactly what you want, because believe it or not, knowing you want a posi carrier isn't enough info. You first need to find out what your current rear axle gear ratio is.

    If you have a 2.78:1 or 3.07:1 gearset, you need a posi carrier from a 1967-1970 Wildcat, Electra or Riviera that also carries 2.78:1 or 3.07:1. If your Riv currently has a 3.42:1 or 3.91:1 gearset, you'll have to find a posi carrier that had those ratios instead.

    In other words, you can't run a set of 3.07:1 gears on a carrier built to handle 3.42:1 & up. Make sense?

    Next, when you know which carrier you need, post in Parts Wanted.

    Then wait.

    Then buy one when it shows itself.

    Then take the car with your new carrier to a good shop that can set it up with your old gears. It's not necessarily a job for a novice.

    Last edited: Nov 6, 2010
  19. grandville455

    grandville455 Well-Known Member

    Good info here, as I believe Jim(Monzaz) has a older set of the 3.42 gears for sale on here, put them in my rear(71-76) i have for sale and u have a nice 3.42 rear!
  20. funkyman

    funkyman Well-Known Member

    I have yet to find out what rear i have.I need to go to a shop and have it looked into:)I do however think that it is a standard rear with a standard gear ratio of that year,so whatever was offered as standard.

Share This Page