Originally Posted By: A_Harman
Originally Posted By: dnewton3
T6 being a group III, there's a giant slug of VIIs in it. That it shears in just about every HDEO application is not unheard of. It's used in motorcycles with shared sumps and it shears greatly there, too. That does not mean it's failing it's job to protect against wear. It's just part of the beast; it seems to shear readily no matter what you put it in, if you run it long enough.
RT6 hasn't been shearing in my Cummins, and there are many UOA's up to 37k miles posted here that show it.
Two thoughts on your UOAs ... and there's no real way to know, but these are observations
1) they certainly are the exception rather than the rule
2) because your UOAs are so much longer, there's a likelihood that you're seeing two phenomenon at the same time; VII shearing is offset by oxidation/soot thickening
I can't prove or disprove it, but your UOAs are not "normal", as most T6 show shearing
Cummins I-6 such as yours don't seem to shear many fluids in normal use, so that also helps.