Yeah, you're right. I think when I wrote the tutorial I never tried cranking it down super tight like some do who run on carpet. As you know the way to adjust the TA03 ball diff requires a partial tear down of the diff itself so that was not something that was tried. My apologies.

However, I've run on carpet and did not have to adjust the diff. There was no "diffing" and the turn in was great. With that being said, it was with a Silvercan so don't know how it would work with the 21.5. I would guess that some tightening would be required. Don't know how the ceramic diff balls would hold up under that ugh pressure.

While we're on the subject, The diff running rough seems to be more of a function of the thrust bearing failing than the diff balls flattening or the diff rings galling. I posted back aways that the thrust bearing is the weak link, so if the diff starts running rough quickly after a rebuild, replace the thrust bearing even if it looks "good". It would be interesting to see what others have experienced with these thrust bearings and compare notes.

I will replace the thrust bearing if the diff has been through a previous rebuild. Since most of he diffs I build will last upwards of a year, this is not a huge expense.