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Ford 9" question, Big or small bearing???

Discussion in 'The Hokey Ass Message Board' started by dirttoo, Mar 7, 2009.

  1. dirttoo
    Joined: Feb 17, 2009
    Posts: 136

    dirttoo
    Member

    I found a Ford 9" rear with small bearings. What is the difference in big or small bearing rears. I see disc brake setups on ebay but they all say for big bearing rear ends. Can you put disc brakes on a small bearing rear? Is there a strength difference? I will be puting it up against about 400 horsepower.
     
  2. Tony Ray
    Joined: Sep 8, 2007
    Posts: 1,007

    Tony Ray
    Member

    28 and 31 spline axles.. 31 are the stronger,, as far as 400 hp.. I have a OT 68 mustang coupe with a 450 hp stroker motor that has 28 spline axles. no problem with it at all even running a line loc on it and 5-6 grand launches, though I did drop $1200 in the center section which is rated for 1000 hp or something like that..as far as disc brakes. .they make em for anything.. just need to find the right kick for your application..or find the right rear set up in junkyard.. think.. lincoln vesallis if you are lucky enuff to get one.. factory rear 9 inch with disk..
     
  3. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,142

    Relic Stew
    Member
    from Wisconsin

    The backing plate bolt patterns and bolt sizes are different, the conversions will be for a specific pattern. The Torino pattern is what was used on the later big bearing 9" and 8.8" most of the disk conversions are factory 8.8" setups and will bolt to the Torino pattern, and can be modified for the big pattern. Big bearings don't mean 31 spline, there are plenty of 28 spline big bearing rears.
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    Last edited: Mar 7, 2009
  4. havi
    Joined: Dec 30, 2008
    Posts: 1,876

    havi
    ALLIANCE MEMBER

    Ford Explorer 8.8's are supposed to bolt on, but I don't know the specifics yet. Or whether it's for the large or small bearing ends. Something worth looking into, anyway. I'm sure some aftermarket brake supplier has the kit.
     

  5. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,142

    Relic Stew
    Member
    from Wisconsin

    The Explorer setup will bolt to the Torino pattern. Another thing I didn't mention before is flange offset. The early big pattern has 2.36" offset, late (Torino) is 2.5" offset, small bearing is 2.66", so there is more to it than just redrilling the backing plate to fit the bolt pattern.
     
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  6. havi
    Joined: Dec 30, 2008
    Posts: 1,876

    havi
    ALLIANCE MEMBER

    Thanks that clears up the confusion, and I don't have to tear mine apart to find out, lol.
     
  7. mtflat
    Joined: Jan 28, 2003
    Posts: 422

    mtflat
    Member

    Correct me if I'm wrong, but the difference in large and small bearings has to do with the hole in the housing. Early axles used the large caged ball bearing setup. Later they went to a tapered roller bearing which is smaller in diameter.

    The only connection between spline count is early axles tended to be 28 spline. The 31's came along later to handle higher hp.

    Disc conversions are often used on early 9" pickup rears because of the width desired for conversions in hotrods and older pickups - 61 1/4". 73 and later used wider housings and aren't as common in swaps. The bearing change took place in generally the same time frame, but Ford used enough variations to confuse everybody.
     
  8. Tony Ray
    Joined: Sep 8, 2007
    Posts: 1,007

    Tony Ray
    Member

    yup I had thought well.. hell I dont know wtf I was thinking.. the coffee just finished brewin..now maybe Ill be able to think.. but always figured that as far as hp and how strong.. it was mostly axle not the bearing that counted.. live and learn
     
    Last edited: Mar 7, 2009
  9. Zookeeper
    Joined: Aug 30, 2006
    Posts: 1,042

    Zookeeper
    Member

    The bearing size has nothing to do with the spline count. Cars like '57 wagons and Rancheros had large bearing housings and axles and 28 sline axle shafts.
     
  10. havi
    Joined: Dec 30, 2008
    Posts: 1,876

    havi
    ALLIANCE MEMBER

    yeah, there's ways to tell by looking at the shaft ends, the diameter of the tubes, and if there's a taper near the flanges to determine large bearing from small bearing. So indeed there's a hole size difference. (response to mtflat's post). you guys are quick, lol. 28 splines are typically a necked down shaft as well.
     
  11. texoutsider
    Joined: Jul 6, 2005
    Posts: 826

    texoutsider
    Member
    from Frisco, Tx

    Big bearing LATE with the races and tapered bearings can be used with the old style big bearings.......simply knock out the races...........

    M.
     
  12. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,142

    Relic Stew
    Member
    from Wisconsin

    The tapered roller bearing is the same diameter as the caged big bearing and can be swapped to an earlier housing. The gotcha is that the seal rides in a different place, so the shaft has to be made for tapered bearings as well.
     
  13. continentaljohn
    Joined: Jul 24, 2002
    Posts: 4,963

    continentaljohn
    Member

    This is what you need:D bolt on and hold the axle in.It's a small bearing TCI style brackets and use GM mid calipers 25 bucks each at auto zone and rotors depend on your bolt pattern. What color do you need gray or red 100 bucks a set.

    Big or small bearing is really only a 5/16 in size and axle strength is were it's at. The 28 spline came in both 8" rears and 9" rears and interchange . The 31 splines don't taper down like the 28's but are Roll splined just like the 28 spline.The big thing is you don't have the C-clip problems like the GM's have . Also the pig comes out easy and quick for gear changes . The 28 can handle 400 plus HP and know a few guys well above that running them, and not very kind on them as well..
     

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    Last edited: Mar 7, 2009
  14. ma70tt
    Joined: Nov 14, 2008
    Posts: 135

    ma70tt
    Member

    i run a narrowed big bearing 28 spline 9" in my OT '92 supra drag car. i went with the wilwood brakes for a bunch of reasons. weight, price, performance, to name a few...
     
  15. Johnny1290
    Joined: Apr 20, 2006
    Posts: 2,834

    Johnny1290
    Member

    A ford 8" and 9" small bearing are the same size, no? I didn't know about that TCI bracket in the post above before, thats' cool since it uses cheap GM calipers.

    I went to pickapart on half price day and grabbed the disc brakes off a '97 crown vic for I think $80, you get the backing plate, pads, rotor, caliper, and hoses for that amount.

    I put it on my 8" ford which I think is the same size as the small bearing 9" and it was a breeze, there was just a little grinding to do at the flange/backing plate to make everything play nice.

    Now I'm redoing my brake pedal setup so I can't report how it works, but I can say it bolts on no prob.
     
  16. HOT40ROD
    Joined: Jun 16, 2006
    Posts: 961

    HOT40ROD
    Member
    from Easton, Pa

    I attach this chart. It has the big and small bearing housing and the ford 8.8 I hope this helps you.
     

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  17. HOT40ROD
    Joined: Jun 16, 2006
    Posts: 961

    HOT40ROD
    Member
    from Easton, Pa

    Could have been a little larger
     

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  18. continentaljohn
    Joined: Jul 24, 2002
    Posts: 4,963

    continentaljohn
    Member

    :D 8" and 9" axles are the same,the bearing are a bit off with offsets and widths..
    Johnny did the Crown Vic have the parking brake in the Rotor hub?

     
  19. Yes, the Small Bearing 9 inch uses the same bearings and brake mounting pattern as the 8 inch.

    The Small Bearing 9's were much more common than the Big Bearing 9's until later on.

    I wonder if we made those brackets in the pic.
    Over the years we have supplied our brackets and stuff to a number of other sellers for their brake sets.

    Here are the installation instructions and parts list if you want to see what is involved in changing to rear discs... the instructions on the website start out like they were for the GM or Ford 8.8, but you can skip the inside-the-differential part when doing a 9 inch or a Dana.

    REAR DISC PARTS LIST + INSTRUCTIONS- http://steeltechsolutions.com/RDBINSTRWORKPAGE.html

    Here is how to I.D. what you have..
    REAR AXLE ID PAGE- http://www.steeltechsolutions.com/REAR_AXLE_ID.html




    A bit of information---
    The common reference to the "TORINO" pattern is almost always referring to the "LATE BIG BEARING" pattern (3.562 by 2 inch pattern with 3/8 bolts). I don't know why people use that term since all the Torinos and Mustangs I have ever parted out or salvaged parts from had 9 inchers with the Small Bearing. Somehow years later the term was widely used to refer to a bigger pattern (Late Big Bearing) that in my experience was very rarely if ever used in a Torino. Maybe a few were used in the later giant-engined ones?
    S0-- if you refer to the "torino" pattern, they might not always know which pattern you refer to.
    It is always best to use the terms "Small Bearing", "Early Big Bearing", or "Late Big Bearing" when you talk to an axle company or aftermarket brake parts company about the 9 inchers.

    Be careful-- The Small Bearing pattern (3.375 by 2 inch) is often confused with the Late Big Bearing (3.562 by 2 inch), so measure carefully the distance between the two top bolts. We regularly have to trade brackets with customers because people will mis-identify what they have.

    (P.S. the 8.8's used a completely different mounting pattern from any 9 inch)
     
    Last edited: Mar 7, 2009
  20. 35PontiacCoupe
    Joined: Jun 7, 2008
    Posts: 232

    35PontiacCoupe
    Member
    from COS


    Not entirely true, the 8.8 Explorer axles from 95 on, which have disc brakes, have the late big ford (torino) housing ends.
     
  21. 35PontiacCoupe
    Joined: Jun 7, 2008
    Posts: 232

    35PontiacCoupe
    Member
    from COS

    After re-reading the thread, I forgot to mention that the crown vic backing plates do have the internal parking brake. I had done HOURS of reading of the different options for disc's on 9" housings and that was one of my biggest possibilities. I ended up welding new housing ends on and sticking with my explorer discs.

    From what I understand, the crown vic setup is basically the same as the explorer setup, but has the housing end pattern closest to the small bearing ends. You have to grind the round part off the bottom, but they mostly bolt up. Oh, and the backing plates are basically the same side plate- meaning that the calipers don't sit facing the same direction like a normal setup. I don't know why, but that's what I've seen.
     
  22. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,142

    Relic Stew
    Member
    from Wisconsin

    I think the "Torino" description came into use because there were several years of overlap between the 2 big bearing end styles.

    For example, the 74-75 Bronco with a GVW of 4500 lbs or less had the late style ends with small brakes, the 4900 lb GVW had the early ends with big brakes. For 76-77 they all had the early style ends with big brakes.

    I've also heard them called the "medium duty" ends by Bronco enthusiasts, because of the big bearing/small brake combination, while the early style ends had big brakes.
     
    Last edited: Mar 7, 2009

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