just got a 9 inch from junk yard and i have a 28 spline ???

okay i got this axel out of a 72 f 100 pickup and it has the big axel tubes and sealed roller axel bearings and 28 spline axel shafts should i upgrade to larger shafts, carrier and bearings or just go try to find a 31 spline unit??? i got the axel for 120 bucks and i might be able to find a 31 spline but i am not sure , oh btw i will be running 36 inch tsls and a spool thx

You can probably find a 31 spline cheaper than buying all the components.
Last time I had to buy an axle shaft, the yard gave me one with the 2800 lb cone bearing. The shop had no problem pressing a new 3300 lb straight roller bearing on the shaft. Thus, bearing style should be neglegable.

ranger125 said:

okay i got this axel out of a 72 f 100 pickup and it has the big axel tubes and sealed roller axel bearings and 28 spline axel shafts should i upgrade to larger shafts, carrier and bearings or just go try to find a 31 spline unit??? i got the axel for 120 bucks and i might be able to find a 31 spline but i am not sure , oh btw i will be running 36 inch tsls and a spool thx

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You'd be better off finding a later 31 spline axle, it will have the heavier duty housing (instead of the banjo style of the F-100) and btw, 28 spline shafts never came with roller bearing axle bearings.....they're sealed ball bearings---------Hans

Oatmeal said:

28 spline shafts never came with roller bearing axle bearings.....they're sealed ball bearings---------Hans

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Now there's one I never new, but the 9" under my truck is a 31 spline in a 4x4 application.

Just because I have not seen a sealed bearing in a 9" does not preclude their existance, but the Ford thing is to lube the bearing with gear oil. If you park off camber for any length of time, the bearing can dry out and waste the axle. This I have seen.

BTW, the tapered roller handles more side loads, like when you corner. Just some food for thought, I don't know what your intended useage is.

thanks for the info guys i am gonna go try and return this pos and get the good one with the tapered bearings , i am gonnapull a shaft when i am there this time he he thanks a million

Hypoid said:

Now there's one I never new, but the 9" under my truck is a 31 spline in a 4x4 application.

Just because I have not seen a sealed bearing in a 9" does not preclude their existance, but the Ford thing is to lube the bearing with gear oil. If you park off camber for any length of time, the bearing can dry out and waste the axle. This I have seen.

BTW, the tapered roller handles more side loads, like when you corner. Just some food for thought, I don't know what your intended useage is.

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28 spline rearends came with either "big bearing" or "small bearing" (these were sealed ball bearings) rear shafts. Most of the cars were small bearing. Early Broncos ('66-'75) were either small or big depending upon the GVWR option ('76-'77 got the big bearing and a beefier housing) all 31 spline truck rearends (as well as the bigger Broncos starting in '78) got the tapered roller bearing shaft. The tapered roller bearing shafts will fit a big bearing housing (bearings have the same OD as the 28 spline big bearing) but, the bearings themselves will not fit the big bearing (28 spline) shafts......the tapered roller bearings (Timken set 20) have an ID of 1.563" and the 28 spline big bearing has an ID of 1.533" There are also different axle flange offsets to accommodate the different width rear brakes as well.....it gets pretty confusing! Did all that make sense(?) I'm an early Bronco nut and my Ford 9" rear has undergone all kinds of changes over the years so, I've done a little research. It's a full floater now, btw .---------Hans

full floater wowsa thats intriging , well i went to the junk yard and pulled 2 31 spline 9 inches. i noticed that the shafts are also tapered a little on the spline end kindof like the 28 spline but yeah huge differnce on the housing these are much beefier units , one diff is out of a 77 f 100 and the other i have no idea one has been abused but the 77 just had normal wear and tear

ranger125 said:

full floater wowsa thats intriging , well i went to the junk yard and pulled 2 31 spline 9 inches. i noticed that the shafts are also tapered a little on the spline end kindof like the 28 spline but yeah huge differnce on the housing these are much beefier units , one diff is out of a 77 f 100 and the other i have no idea one has been abused but the 77 just had normal wear and tear

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Cool! I'm glad you got what you wanted. Here's a link to some good stuff if you need it for your "new" rearend: www.tomsdifferentials.com he has high quality stuff with really good prices. He was a good guy to deal with when he was here in SoCal--------Hans

yeah i am pretty pumped i think i may tear apart the mystery 9 inch and see whats makin the noise hehe