I have a 2006 - 6cyl - manual trans with 106,000 miles on it. I bought it new. Never had any issues!!! Was taking it last week to have its first tune up (really). Speedometer stuck on the way. The code check said it was the. After the tune up it ran like new. We replaced the speed sensor but it did not fix the speedometer. We pulled off the differential cover and found only 2 ring in place, 2 bolt heads (perfect condition) sitting in a pile of metal sludge, and all the teeth gone from the ring gear hence the speedometer not working. There had never been any issues or rear end problems ever!
First: It is obvious this did not just happen!
Second: Is it possible this was a factory condition - not torqued properly?
Third: I can not afford to rebuild it - $2700 Quote. Going to use a used (not my first choice).
Fourth: Has anyone seen this condition before who can enlighten me on how this could happen?

 

I've never seen something like that before, but if all the teeth were gone from the ring gear, how did you manage to drive the truck?

If the truck wasn't abused, the bolts may have been defective or improperly installed, but try to prove it one way or the other - your cheapest solution would be to get an equivalent axle (the whole thing) from an auto salvage yard and install that - you should be able to do the swap yourself and it should be just a few hundred dollars for an axle in good shape. If you have a garage do the swap, you'll need to factor in about $100 to $150 per hour for the labor. The replacement axle will need the brakes looked at and you'll certainly need to bleed the brakes after attaching the lines, and you should open the diff to have a look and change the fluid as well.

Your VIN should be able to tell you which differential ratio you currently have. If your truck is a 4x4, both diffs will need to be the same ratio - you can count ring and pinion teeth and work out the ratio that way, or you can turn the input & see how many turns it takes to turn the hub once, or you can get the VIN decoded to confirm - some diffs have a tag on them with this info as well.

 

That is terrible! once again Dodge JUNK!

 

I probobly used the wrong terminology. It was the Ring gear that triggers the Speed sensor not the ring gear that slots into the drivetrain. However they are all held by the same bolts. I guess that the last 2 boltes were pretty strong. I am going to attempt to convine Dodge that this condition started before the warenty was out. I may not achieve it but if I do not try, I will never know.
I have to admit however that 1 tune-up in 106,000 miles and not even having to perform a break job is pretty good. Maybe this piece was made in Tiwan. LOL.
I appreciate the input from the forum.