So I'm changing the diff fluid in my rear axle today. Pop the cover most of the way, and drain the fluid. Once most of it is out, I take the cover all the way off. I'm looking around inside, and it's definately got LS.

Then I notice two things, the second immediately after the first. There's a BIG chunk missing from the inside corner of one of the ring gear teeth.

Then...

Holy sweet mother of.... what is that stuck between the carrier and the ring gear?!?!

Of course, it's the missing chunk of ring gear, bent and mashed to a completely unrecognizable state. From the looks of the inside of the diff cover, it made a few trips around before it found a final resting place. At least there's that. I pryed it out with a screwdriver, and got a good look at it.

If the jolly green giant picked his nose, and had what came out cast in steel, this is what it would look like in real life. Even the size is right.

Other than that, the axle seems ok. I don't know what it would sound like if it needed to be rebuilt, though. I do hear some kind of growling, but I think it might be my tires.

Two questions: should I have a shop look at it? A nugget that big can't be doing healthy things to my differential. Also, how could this happen?? The contact patch between the ring and pinion is in the middle of the gear, not on the corner - where did the force come from to break the gear?

I'm going to borrow my friend's camera next week, and post pictures of this thing. You've got to see it.

Oh yeah.. I'm glad it's build FORD tough!

 

BTW, that last comment isn't sarcasm! I wonder what would happen to a GM 10-bolt if a chunk that big broke off..

 

I think most mechanically minded individuals will realize you are not being sarcastic. As far as the chipping of the gear I have not had the misfortune to see this in my truck but I can say that I have seen it happen in ATV gearboxes. I guess a good shock to the drivetrain could cause enough pressure to chip the teeth to the outside of the main contact point. Kind of like flint was formed to make an arrowhead. Sorry, my memory of point defects and materials is getting foggy! Mmmm beer. . . . .

 

Oh yeah, my memory is getting foggy too! I meant to say that should you replace your differential I would be interested in your LS components if they are in decent shape!

 

I've done that. While off-roading, I backed into a short rich-pine stump that dimpled the cover into the ring gear. On the way home, the oil drained out and the gears overheated. I refilled it, but about 2 months later, it chewed up a couple of teeth. 2 off the ring & one off the pinion, I think.