Originally Posted by
gubbs3
As will all other things, not all CMMs are the same. While the most common will have a length measurement error of 2.5um+L/200mm and can be used right on a production floor, others go up to .3um+L/700mm and require temperature controlled labs which are more than capable of those tolerances. However, I highly doubt TKO would opt for the million dollar option when the $60,000 version will do well enough for our needs. But that still doesn't rule out that they may outsource their inspection process.
Unfortunately the rings alone won't make for a smooth diff. Axles and hubs are usually off far enough after a few good whacks where you'll get tight spots as you spin the diff.
I have been running the same diff rings from TKO since October on my Associated 12R5.2 and have dozens of runs and many race days on them. All I can say is they are as smooth as butter. I used CRC's diff balls for the diff and haven't had a reason to switch out to the TKO ceramics yet as the diff is still so smooth. I had to replace the original rings only after a few practice days as it became extremely gritty.
So all I can say is Try them and see for yourself......