Ulterra shaft...what is this?

[RichW]

I try to wipe down the shaft as recommended with a water based silicon lube. I spray a paper towel & then use that to wipe...but lately I've been seeing this black residue on the towel even when having fished on clear waters. Anyone else see this? Could this be from some internal lube residue? I see this even on short trips so I don't think it could be road grime.

[bobcoy]

I am betting on the trim belt is rubbing against something.(belt dust) Look on the sides of the belt for wear. I have not had the issue, but have seen examples on this forum. Bob

[Bradrodfish]

This is composite dust which is created when the shaft goes up and down through the steering module and the trim module. Keep an eye on this and check the sloth that belt sets in to make sure that the edges of the slot are not getting rounded off to the extent that fiberglass strands are exposed. this happens when the motor is deployed and stored and the shaft rubs against the steer module. Not uncommon to see this dust in small amounts when cleaning the shaft.
Your case looks normal to me.
The dust will also be found on the Ultrex also.

[Mark Wendler]

This is composite dust which is created when the shaft goes up and down through the steering module and the trim module. Keep an eye on this and check the sloth that belt sets in to make sure that the edges of the slot are not getting rounded off to the extent that fiberglass strands are exposed. this happens when the motor is deployed and stored and the shaft rubs against the steer module. Not uncommon to see this dust in small amounts when cleaning the shaft.
Your case looks normal to me.
The dust will also be found on the Ultrex also.

I concur!

[RichW]

The belt & slot look good, but I'll keep an eye on it. Thanks!