Just got done with replacing the impeller in my 1985 mariner 25 and upon an attempt at reinstalling the L/U I quickly found the shift rod in the lower unit has become jammed (stuck in forward). I am completely puzzled as to how and why this has happened as the engine has operated perfectly up until now. Any help from the experts out there as to how to fix this issue and perhaps an idea of what I did wrong would be fantastic. Thank you!