That's my pic, it came from a 74 Comet. The one under my 74 Mav is just like it, as is the one I pulled from a 73 4 door.
Sooo... does anyone else find it curious that the 3rd dimple is in the same location at the pre-'67 fill plug location? My other housing came from a '73 Maverick and only has two dimples. Most of the 8" housings I ran across in my Google search were pictured only having two dimples. Wish I could tell you the ratio, Gene, but I just bought the empty housing off the guy. No center section. My old housing was sourced from a '73 junkyard Maverick and upon a thorough cleaning, found to have one of the axle tubes re-welded. I don't trust an "aftermarket" weld on a piece as critical as an axle tube. The other guy may not have welded it square and true. Oh well. You guys are, more-than-likely, absolutely correct in the concept of it being an oil-slinger. However, my search for concrete evidence continues. We may be about to uncover the biggest Ford conspiracy known to man. :16suspect
there is nothing curious about it. when ford moved the fill plug to the third member they just removed the steps of the process that stamps the hole and threads it in the housing. its allot cheaper than makeing a new stamping process just to smooth out the housing. the housings that dont have this may have come from another plant or they remade the dies for the stamping machines as they wore out with out the fill plug dent.
Perhaps it became cheaper to have the drain plug hole cast, drilled and tapped into the center section... then to stamp and weld the fill plug adapter into the sheet metal housing?
Probobly one of the reasons. I don't know what the plug/fill hole looks like on the housing. Where it goes seems like it could be trouble. Being that the oil is slinging there maybe some units were found to be leaking. 1 too many complaints or warranty repairs and they moved it.. Maybe the bung or whatever threading was getting stripped often in the line and causing alot of housings to be sent back. It would definetly be a buzz killer to be on the line and already have the diff under the car, be filling it, then strip it.
Just a guess, but maybe the fill plug would be too close to the ring gear? If I'm not mistaken, the older rear housings had more of a curve out the back. I just looked at mine ( 74 ) and it has that depression in the center too.
That was what I was wondering at first. That's why I was also curious about what gear he had. Mine is a 3.00.. well it WAS. Now it's a 4.62.
But, the fill-plug was removed in '67. Why, then, would there be housings dating into the mid-'70's with this dimple still there? Surely, the stamping dies would have been phased out long before this. As mentioned earlier, the axle tag from my old housing dates it at '73. It has only two dimples. Others have mentioned their axles have three dimples and were stamped ranging between '72 and '74. Therefore, we have two different housings being produced a the same time. You may be on to something with the "another plant" idea, though.
Does it look like mine has the third dimple? I am too lazy to go out to the garage and look. This is the original rear axle on my 1972 Grabber.
