How to Narrow an 8 3/4 Rear End

  1. jtkaaa07
    I am in the process of putting a mini tub kit, spring relocation, and axle shortening in my 69 dart, and thought I would share pic's and a how to on the shortening of a housing.

    As with most housing's this one was bent right from the factory, this rear end came out of a C body Mopar.


    Rear end measuring tool, is a must have for this job, bought on Ebay for $25


    Bought a junk 741 bare housing to use with jig


    Put the cent plug's from my jig in the carrier, and tightened up caps, then check to make sure it moves freely side to side


    I cut the old ends off the housing, and cleaned them up in the lathe, make sure to have a nice taper on end to get good weld penitration, you can also buy these brand new if you don't have access to a lathe, Dr Diff, and a few other vendors have them in billet steel as well


    Make sure to taper housing ends too


    Cut housing to desired length, I made mine 48", with 36" perch centers, this is where the rear end ruler is really handy.


    Time to straighten bent housing, I have 2 1/2" inch plugs that fit in the inside of axle tube


    Plug on one side with threaded rod end


    In the jig, chained to table, then heat on the side in the direction you want to bend it, apply pressure from jack until lug slides in smoothly, then let cool completely before removing anything


    The threaded plug in my kit has a notch cut in it this is how you clock the end's, they can be off a little without any problems with E brake or anything else





    All finished and ready to go back in, now it's time to shorten the Moser axles, I send those in to machine shop, and have them cut, splined , and re hardened

    Forgot to note, never remove any of the jig until the housing cool's on it's own, do not use water, or wet rag to cool it down or it will twist all over on you, trust me I've been there!! after it completely cool's off the plug's should slide out without much interference at all. I know there will be many here that would say just ship it to Moser, and I would have to agree in most cases, but a good friend of mine has been doing these for many year's and he set me up with the jig. I'm the type of person that has to try and do everything on my own, so hopefully this will help anyone wanting to try it.

    Almost time to get some tire under this beast, soon!!


    Hey guy's, I thought I would post some pic's of the progress, spring relocation kit is in, axles are on there way to Moser, and brakes are rebuilt! Next step is Mini tub, hopefully that will be done this weekend or early next week.





    I took 5" off the stock length of an A body rearend, and just so I don't get hung on the cross, no factory A body housing was used in this project, that's up on a shelf just in case this doesn't work. I think I'm going to set the axle back an inch from stock, my tires were really close to the front of quarters before, and the nice thing with doing this is, you can adjust up, down, forward or back by just moving to another hole.





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