Today I took my buddy out fishin and he turned a good day into a headache real fast. The boat drifted away from the bank with just him in it and long story short when he tried to get it back to the dock himself he managed to shift it into reveres with the throttle wide open. I wasn't right there to see it but I haerd it and it about made me cry. the forward gear still worked fine but there was nothing there when trying to shift it into reverse. I dont know a whole lot about the internals of a lower unit but i knew it wasnt good. I dumped the lower unit oil when i got home and it was full of metal shavings and shards just like I figured. The motor is an 89 evinrude 40hp. my question is is there any hope of fixing just the reverse gear or or should I start looking for an entire lower unit. Any help or advise would be greatly appreciated since Im no marine mechanic.