kinda odd tranny noise

[F350oldskool]

hey yall, got a 2001 with a zf6 and in neutral it has this weird grinding/vibration that starts then stops then starts again. it seems to go away when i push in the clutch then let it out again. i also hear it again when im in 4th gear? sounds like some kind of bearing goin out. any ideas??
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[kingbilly68]

Throw out bearing??? Maybe..

[F350oldskool]

do you know if you can grease it?

[kingbilly68]

Idk... My past experience they had to be replaced. I normally just went ahead and did clutch while I was in there. Maybe someone with experience with a zf 6 will chime in.

[350 ONE TON]

pulled a few out and none of them looked like they were greasables