Rearend identification

Discussion in 'Got gears?' started by Lory's 350, Mar 31, 2020.

  1. Lory's 350

    Lory's 350 Active Member

    Hello guys,
    Can anyone identify this rear end and can say me how much it can handle? It is 155cm wide and got very long gears.
    Thank you!
    Lorenz
     

    Attached Files:

  2. Luxus

    Luxus Gold Level Contributor

    Monzaz will probably chime in with his opinion on this. Basically they are usually identifiable by what the rear cover looks like. All I can say is it's probably a 12 bolt.
     
  3. Lory's 350

    Lory's 350 Active Member

    I bought it as a big block axle out of a gs. But what gear ratio does the gs had?
     
  4. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    You need to count the teeth on the gears
     
  5. Luxus

    Luxus Gold Level Contributor

    You can get a rough idea of what gears it has by rotating the wheel/axle and watching the axle yoke. See how many times the yoke spins for one wheel rotation. For example for one wheel rotation, you see the yoke spin about 3 and a half turns. So that means you have something around 3.500.
     
  6. BrianTrick

    BrianTrick Brian Trick

    That rearend is a 67-69 12-bolt O-axle,or also known as the Oldsmobile 12-bolt. They came under all Cutlass/442’s that were NOT built in Canada. Those rearends are unique to themselves. Parts are limited,but they are a good rearend. You can get new posi units for them and a choice of 3:42 or 3:90 gears.
    They also made that rear in 1970,but the axle bearing and bearing retainer were slightly different,so I know that one is 67-69.
     
  7. Lory's 350

    Lory's 350 Active Member

    The ratio was 2.56 when i remember right. But what about the strength? Can it handle a 500hp 455BBB?
    Thank you
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Yes, it is like the 8.5 ten bolt.

    http://www.jdrace.com/content/diff_id/12bABodyOlds.php

    It was an expensive rear to build last I heard, but it was a sturdy rear. Sounds like you probably want to change the gearing so I would sell it to an Olds guy as suggested and find a 71-72 8.5 10 bolt out of a Skylark/GS or Cutlass. That is what I have in my GS. I upgraded to 30 spline Moser axles, Eaton Posi and Yukon 3.73 gears.
     
    Last edited: Apr 1, 2020
  9. BrianTrick

    BrianTrick Brian Trick

    It will handle the power,but yes,a little more expensive to build than the 71-72 8.5” 10-bolt.
    I sell a complete kit to rebuild an O-axle,for $1150.00 WITH the shipping included. Actually shipping one out today. Parts included are:
    New Richmond gears,3:42 or 3:90 ratio
    Yukon clutch style posi unit
    Timken bearings/seals for the entire rearend,including axle bearings/seals
    Complete install kit with carrier shims,pinion shims,crush sleeve,pinion nut,ring gear bolts,loctite,and gear marking compound.
     
  10. Bens99gtp

    Bens99gtp Well-Known Member

    Brian. Just so the OP can compair, what does the same kit for a 8.5 cost.

    How are the axles same spline one not compared to 8.5.

    If the cost of kit is a couple hundred less and this has 30 spline the OP might be farther ahead to build it.

    I know a stk 28 spline axle 8.5 will handle 500hp in street trim no issue......the addition of sticky drag tires might be enough to twist an axle eventually.
     
  11. BrianTrick

    BrianTrick Brian Trick

    His O-axle has 28-spline axles,but you could build it with the optional 31-spline shafts and matching unit. Yes,31,not 30. That’s what Olds had. I’m actually building 2 of them right now with the 31-spline shafts.
    The same kit for the 8.5” 10-bolt would be about $200.00 less. My kit would have a Motive Performance gearset and a Tru Trac posi unit,along with all of the Timken bearings/seals,and the installation kit.
     
  12. Lory's 350

    Lory's 350 Active Member

    Ok, thank you to everyone. This rearend is rebuilt, and i want to know if i should take it for my bigblock conversion. But i think i will sell it and buy something else.
    It is really hard to find a good one in germany so i will buy a new one in usa.
    what about a ford 9inch for gm a body, from moser or strange?
     
  13. BrianTrick

    BrianTrick Brian Trick

    That rear will work,BUT if you want to buy a new,aftermarket rear,I would buy a Moser 12-bolt,or a Strange S60.
     
  14. Bens99gtp

    Bens99gtp Well-Known Member

    After doing lots of looking I really like the s60 if going that route of aftermarket
     
  15. Lory's 350

    Lory's 350 Active Member

    Strange S60 sounds good, and the price is nice too. Before i spend 1000bucks in a axle that is limited in strength and gettin parts, i will spend the money in a bulletproof new one. How much hp/tq can the S60 handle?
     
  16. monzaz

    monzaz Jim

    hp aND STRENGh can only be determined on where your driving the car....STREET bound most ALL rears can handle gobs of torque and HP because they just never hook up....When you get to the sticky track that is when drive line parts find thier limitations.
    Jim Mitschke
    JD Race
     
  17. Lory's 350

    Lory's 350 Active Member

    Most times on the streets. In germany 1/4 mile is on a non prepped little airport. So bringing the power to the track is most times a problem...
    is there any info what it can handle? 700hp proof? Or more like 1000hp?
     
  18. Bens99gtp

    Bens99gtp Well-Known Member

    S60come standard with35 spline axles and ring gear is 9.750inch. And 40 spline are available
     
    Last edited: Apr 7, 2020
  19. monzaz

    monzaz Jim

    LOL. THERE IS NO guarantee on torque to the ground. Sorry...I will not throw numbers as it always seems to get a big argument in the forums. So talk with Strange , Moser or Currie etc. Let them put there money where there mouth is...
    I run a Stock 10 bolt 8.5 from a S-10 (4.3 5 speed optional rear) to 10.5 in the 1/4 mile pull the fronts 1 foot to 1.5 feet in the air on launch 33 spline spool and 33 spline axles 3.90 gears.
    8-9 years same set-up
    look at the avatar.
    I would worry more who is building your rear differential for longevity then how BIG a rear you get.
    I will not let Moser or anyone else build my rear differential unless it is a Ford 9" because I just do not care about them...LOL. :D
    Sorry pet peeves here on the 9". My personal hurdle.

    J D Race
    Jim
     
  20. Bens99gtp

    Bens99gtp Well-Known Member

    My 30 spline 8.5 with 4.30 gear is carring my 3650 pound car to low 6.50s in the 1/8th at 104 mph. With low 1.4 60fts. Planning to go more the sunmer
     

Share This Page