[66Chris289]

I

I feel like I’ve tried every combination of words, searching google for some variation of chip/crack/break/broke and axle housing/housing/carrier mounting surface, etc but I can’t find anywhere else this issue was discussed:

I was just about ready to bolt the new drop in center section on the ford 9” rear last night, which I was replacing after finding a broken tooth on the pinion gear. When I was back under there to clear the old gasket and get it ready, I saw these cracks on the carrier mounting surface for the first time.

They don’t extend into, but are both more or less lined up with the axle tubes. I can’t fond an answer on whether or not that’s enough of a problem to stop and repair or replace the housing, or if I’m good to go as long as they’re not big enough to interfere with the new gasket doing it’s job. (Ordered a new lube locker gasket with the center section as opposed to going with more gasket maker, but if gasket maker is the solution to work around these chips, then I’m fine with that. Thanks!

 

[GT350HR]

It is common to "most" factory made 9" housings. "That" portion of the housing is "two halves and a back plate" all welded together. When the front face is machined flat to accept the differential , it is common to have a couple of areas like you've shown. As long as there aren't any cracks in the welds themselves , you are fine. If you find cracks in the machined area they should be repaired and the housing braced.

 

[Jedi]

I would grind the inside chips out, and probably camfer the inside edge all the way around

 

[66Chris289]

It is common to "most" factory made 9" housings. "That" portion of the housing is "two halves and a back plate" all welded together. When the front face is machined flat to accept the differential , it is common to have a couple of areas like you've shown. As long as there aren't any cracks in the welds themselves , you are fine. If you find cracks in the machined area they should be repaired and the housing braced.

Not only did you just help me out big time, but maybe the next person to google it can find the answer nice and quick.
It was already getting late last night and I just stopped where I was at so I can go inspect what you mentioned specifically and move on from there.
Thanks!!

 

[66Chris289]

I would grind the inside chips out, and probably camfer the inside edge all the way around

Great. Sounds smart to me. What’s the ideal method for making sure the housing is 100% free of metal dust and pieces after that process? I mean, I understand it could be as simple as just running a magnet all around there and that’s what I did last night after clearing the old gear oil but is there a trade secret way that’s really successful?

you reminded me of something else too, and maybe this is a different thread, but I remember seeing or hearing about a magnet being used inside of differentials to collect any shavings or debris from break in / continued wear. Since I’m replacing a center section that broke, I’m probably a little over conscious of the notion of loose metal pieces floating around in there.
Wondering what the ideal solution is for keeping a magnet in there for operation: size, type, location and securing the magnet if not just relying on the magnetic force itself.
Thanks!

 

[GT350HR]

Not only did you just help me out big time, but maybe the next person to google it can find the answer nice and quick.
It was already getting late last night and I just stopped where I was at so I can go inspect what you mentioned specifically and move on from there.
Thanks!!

That's what we're here for ! Lot's of VERY knowledgeable guys here besides me. As much as I know I still learn from other more well versed in certain areas.
Randy

 

[GT350HR]

Just lay a 3/16ths to 1/4" thick magnet in the bottom of the housing and let it eat. It will stay in place. It is a great addition.

 

[awhtx]

I have a few 9" housings laying around. Does this make you feel better?

 

[Maxum96]

As GT350HR said, those "chips" in the housing are normal. a magnet is a good way to get metallic debris out. I like to wipe out the inside of differential housings with a clean lint free rag or paper towels when replacing gears.

 

[66Chris289]

I have a few 9" housings laying around. Does this make you feel better?

Sure does!

 

[disquek]

A magnet will get the steel from the housing, but it wont get the abrasive particles from the grinding wheel. I'd either leave it alone (it's been like that for 50 years), or I'd figure out a way to tape or otherwise cover the inside so you don't get anything in it. Cardboard, and tape, etc.

 

[dacofa]

Mass production my friend. I always use the magnetic filler plug.

 

[74Rallye]

If you grind it smooth you'll never get the grit out without an extreme amount of cleaning. Let it ride as is.

 

[markb0729]

JB Weld? Especially if it's not under a lot of stress in that area.

 

[Rufus68]

Why risk providing a hard epoxy chunk to break loose if it is not needed? I would vote no to the JB Weld here.

 

[74Rallye]

It's always a good idea to step back and question anything that doesn't seem right. What you're seeing is normal. Anything you do to "fix" your chipped areas will create problems.

 

[dacofa]

Did they leak? If not, leave them alone or you could make it worst. They're not a problem now and you could create one by messing with them.