My 2005 Ram 3500 with the AAM 11.5" Diff started making bad noises. At first I thought it was just the brakes, so I replaced the pads and rotors because they needed it with over 100,000 miles on them. That didn't help, so I pulled the axles and spun the tires and checked for loose wheel bearings, but they seem fine. I pulled the driveshaft and checked the U-Joint and the differential pinion and back lash at they seemed OK?
I pulled the diff cover to see if anything looked messed up. This is what I noticed on the LSD, the small worm gears were showing through the side of the case, but I don't know if that is how they are supposed to be, or if this is a bad thing?

That is how the carrier should look. How much backlash? Should be like .005-7 maybe a touch more. Now that you have the axles out spin the wheel to try to reproduce the sound. If your that far Id still throw new bearings/races on the carrier and pinion.

Thanks. I have been looking, and did see that is how they are supposed to look. I will have to do some more inspection, and see what I can come up with? I'll check the pinion preload tomorrow, then hook up the driveshaft and take it around the block in 4wd without the rear diff installed.
This axle is easier to work on than my Dana60. It has adjusters for the back lash, so I did not need to use the case spreader.

Side note. If I need a new Diff, should I just get the same AAM TrackRite or an Eaton TruTrack?
I wish that AAM had the TrackRite GTL for the 11.5" axle. It's a helical limited slip with electronic locker.

Dang, found the problem. Not the rearaxle, but the driveshaft center bearing. I guess I totally missed that one working in the driveway, at night, with just the light from the garage
Now I just have to measure the center bearing size, looks like there were two different sizes used? Then put the diff and axles back in. I needed to change the gear oil anyhow....

Went to get U-Joints for this driveshaft, and foun out Dodge used multiple vendors so there are different sized of U-Joints. After measuring the U-Joints, found they are 1410 size. Now just have to replace them, but they are pretty rusty, busted a few of the old outer snap rings removing them.