Tweet
Lower Unit
I have a 99 200 hp saltwater series. I noticed when I was changing the lower unit oil, there was a small amount of metal fines on the screw attached magnetically. Is this normal, or should I be concerned?
Thanks
Thanks
-
-
wClery
I have a 1991 and have always seen fines. Everything wears till it breaks I say this is normal and really would not invest money in preventive work only to have the fines start again.
Getting technical, what you are trying to do is keep the hard particles smaller than the dynamic film thickness at the intersection of the gear teeth. These fines are probably larger than the dynamic oil film but the teeth are not crushing the fines as much as moving them out of the way when they mesh. In hydraylics gear pumps and motors are known as dirt eaters meaning they can take a lot of abuse before failure. Worn teeth can mean slop between the teeth but most of your driving there is constance forward resistance thus tending to keep the teeth together. The slop occurs when the throttle is reduced but at that time there is much less force on the worn teeth. In short - I would live with it and enjoy the ride.
Comment