9 1/4 rear vs 8 3/4 rear, will brake parts interchange?

Brakes, Steering & Suspension

  1. satilite73

    satilite73 Well-Known Member

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    Will the backing plates, and drums from a ('77) 9 1/4 work on an ('73) 8 3/4 axle?

    The 9 1/4 received all new brakes just before it was pulled and buried in the back of the garage.

    I don't mind tearing down the 9 1/4 to find out, but the 8 3/4 is currently in my wagon, so I don't want to tear it down at the moment.

    Just curious before the 9 1/4 gets tossed in the scrap pile.

    Thanks.
     
  2. F4R/T

    F4R/T Well-Known Member

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    I wouldn’t toss the 9&1/4! If your swapping to have a banjo type rear diff I could see but otherwise why? Not a bad rear diff just doesn’t drop out like the 8&3/4. Donate what you don’t use to someone one forum before scrapping if nothing else..
     
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    • 1 Wild R/T

      1 Wild R/T FBBO Gold Member FBBO Gold Member

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      Yes, the brakes bolt right up... But I agree someone might be able to use what's left...
       
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      • satilite73

        satilite73 Well-Known Member

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        I've had this 9 1/4 for over 30 yrs. It was originally in a '77 Gran Fury (C-body) cop car. I originally saved it because of it having sure grip. I put it into another vehicle and racked up over 100K miles of use and abuse. In total, it probably has around 250K miles on it.

        At this point, it needs to be gone thru completely. The sure grip is shot, the pinion seal leaks, and I think one of the axle bearings is going out. Plus it needs new spring pads welded on. The whole time I used it, all I did was change the oil once when I pulled the cover to see why the SG wasn't working anymore.

        The 8 3/4 is original to my wagon and I currently have an 8 3/4 in it I pulled from a '71 Chrysler. The original axle wasn't set up correctly or something, and was giving me problems. I was parting the '71, realized it was the same width, I swapped it in for the time being.

        I've tried to sell or flat give away the 9 1/4 locally a few times over the past 10 yrs with no takers. There's no way I would ship it.

        If you've read this far, let me ask another question; regardless of what originally came in the car, if you were setting the car up for a lot of traveling, which one would you use?

        (I must be tired, not sure why I said the '73 axle was IN my car when I know its not. I just don't want to tear it down right now. Didn't mean to confuse)
         
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        1 Wild R/T FBBO Gold Member FBBO Gold Member

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        8.75...
        A) cause we know they are durable...
        B) cause gear swaps are easy... Traveling put a 2.76 in it... Normal driving a 3.23..
         
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        • Big Bad Dad

          Big Bad Dad Well-Known Member

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          I had a 9-1/4 in my 78 Dodge pickup. After I wore it out, swapped in a 8-3/4 from a 72 pickup. I swapped all the brakes over with no problem. The 78 had the bigger brakes, and the backing plates bolted right on.
           
        • 66Satellite47

          66Satellite47 FBBO Gold Member FBBO Gold Member

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          I would think the 9 1/4 with limited slip is worth a fair amount. They are a very tough.
           
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