Omc 235 electric shift lower unit oil

[Thane2012]

Hey guys I have a question about my omc electric shift. Yesterday I replaced the oil in my lower unit with type c omc oil and when I was draining the oil I noticed a little bit of black type sludge there wasent a lot but it concerned me a little bit, is this normal? Keep in mind I rebuilt the lower end with a new forward spring and new bearings at the beginning of the summer. Thank you Tim.