I did that exact thing thing to a 9" a long time ago. I got tired of cracking the chunk everytime I wanting to change the diff oil. Which was often because I was submerging my 4x4 a lot.Being that it already has an existing fill port, why not drill and tap with an 1/8" pipe tap for an 1/8" allen key flush pipe plug far enough forward in the casting, and off to the side so its not lined up with any of the bolt holes or close to the back to lessen any stress. I marked in the pic where i think it would be a good idea for a drain plug. Its far enough forward that it wont weaken the casting. Its between 2 bolts and not lined up directly forward of one. 1/8" pipe plug is a small hole, so it shouldent weaken the case much if any. I wouldent recommend this for high HP applications but 400-450 application i would think it would be fine. What do any of you think about this?
View attachment 1715228886
View attachment 1715228887
Bottom of the housing.Did you drill the chunk or the steel axle housing on that 9" ?[/
I wouldn’t do it just buy an aluminum cover with the drain plug and be done with it. This one has fill, drain, and girdle it’s a triple threat.Being that this housing is cast, i am having second thoughts.
I personally prefer this one simply for the fact it doesn't say Ford on it. And it's more speak appearing just my personal opinion.However once you fill it, how often do you plan to change the diff fluid? Every 50k? If so what about one of these and be done with it. 50K might take 10 years or more to put on one of these cars unless its your daily driver. Unless the coolness factor of the finned cover is what your after.
View attachment 1715228521
I was headed that way actually.I personally prefer this one simply for the fact it doesn't say Ford on it. And it's more speak appearing just my personal opinion.