So I have been fighting a odd noise for some time. A chattering noise like a chain grinding against something under light drive train loads, such as slowing for a stop or going down hill with light pedal. Most annoying and would usually go away with a slight blip of throttle or braking. At first I suspected the transfer case chain or some component. I had the transfer case apart three times looking for a issue in there. Finally I changed the chain with another used chain I had and swapped the differential with another which passed the bias test better. At first the noise went away and then it slowly started to make the noise again with more and more frequency with time. I even got one of the new chains and was ready for another transfer case tear down. I was doing another drive train inspect for obvious issues and came to find a bad spindle bearing. At first it was not obvious because I had the transmission in park. Once I set the brake and shifted the transfer case into neutral it became apparent that there was a lot of play where the axle stub goes into the back of the spindle. I did not even know that there was a bearing there.
After replacing the bearing the first thing I noticed was that the clunking I had when I shifted into gear was gone. I thought the clunking was due to a loose chain or some wear in one of the splined shafts, even though I could never find any wear in the transfer case, I had already checked the U-joints and rebuilt the CV-joint.
Two day of driving and no chain rattle noise so I am really hoping that this has taken care of this annoying condition for good. A bonus is that it does not clunk shifting gears now.
I think that the noise went away for awhile becuse the clutch bias on my old differential was low to the front axle. Once I replaced it with a differential that passed the clutch bias it supplied a stronger load on the front axle and kept the spindle bearing from rattling until it wore down to a point where it started to rattle again.
Now that I think about it, I never had the noise until I had a bad spline in a cone clutch. I tore down the TC to replace the cone clutch and right after that is when the noise showed up. I thought I had done something wrong with reassymbling the TC and soon after I parked the Jeep. Fast forward 9 years, once I got the Jeep up and running again I heard the noise so I figured it was still in the TC. Two tear downs later I find that the front clutch bias was out of spec and replaced the differential with one that passed spec and noise went away, for awhile. Now I am thinking that the clutch bias was good to the front axle with the old cone clutch years ago. The installed cone clutch must of been out of spec and lightend the load on the spindle bearing which then allowed it to rattle around in the housing. Me having just been into the TC thought I had done something wrong. I never checked the clutch bias back then, never even knew that could be a issue.
Figured I would post since this may come up again.