Any thoughts on this? These gears have only been in for maybe 6 months. It a 10 bolt. Behind a 5.3 and 4l60e

 

Are those pieces sheared off I see? Looks like it was a surface defect that cause a crack to propagate.

 

It looks as if someone took a grinding wheel to them. Its only 7 teeth the rest look ok but they are dark spots in that area.

 

Who built the rear? Looks like it was never patterned and shimmed. Maybe someone just replaced the pinion and ring gear and never set it up correctly? I'm also curious to know what brand the gears are.

 

I local shop, Corky's performance. I had them upgrade the gears to 4:10s, and the gears, I believe are the summit racing gears.

 

Well since it is apart now, you might as well throw some paste on the gears and look at the pattern. That will tell you if the shop set them up correctly or not.

 

To me, it looks like the pinion is too close to the ring gear, that's the wear on the crown or top of the gear. And also the backlash needs to be increased to move the pattern more towards the center of the face. In fact, it need to be patterned and set right. Maybe there was a burr under the ring gear and it's not set on the carrier flat?

 

This might just be the 2nd sign telling me to do a 8.8 swap.

 

Was there metal in the rear end?

 

A swap is always an option, but i would resolve the gear change problem with your builder first. If he did a gear change swap and didn't take the time to set up a proper pattern and check the tolerances, I would say he owes you something.

 

The teeth on the ring gear were ground down so that the block in the center of the differential could be installed. The ring gear is too thick for the block to go in without grinding a few of the teeth down a little. It's no big deal. A very comon problem, especially with the smaller rear ends.

 

I have seen that before also that why I was wondering if any metal was found in the diff.

 

If it was done right then it should have been done before the differential was installed in the housing.

 

Maybe it's because your car is upside down

Haha or the picture is. I've heard of that- grinding down the teeth to slip the paddle into a torsen diff.

BigGearHead nailed it.

 

Didn't appear to be more than normal

 

I never heard of grinding the teeth either, but I went to a closer shop to my job and they said the same thing. That sometimes the teeth have to be grind a little to put the block in. But I'm pretty sure I took it out the spun the gears by hand and discovered this but oh well.

 

A 3.23 gear set has a thin ring gear and the block can be installed without grinding. When you get to gears like the 4.11 the ring gear is thicker and sometimes needs a little clearance to get the block in. With other differentials that have a round cross shaft you can grind a flat spot on the shaft to get enough clearance to install the c clips.