i wouldnt oil anything!! armorall is the best thing ive found for the shaft, makes it glide up n down when deploying and stowing effortless, you could check the brushes but if its quiet and has no lack of power i wouldnt advise it unless you have disassembled and assembled a lower unit before, its very tricky but simple if you know what your doing. check your prop for wobble out of the water(only let it run a few seconds) if it has a wobble try popping it off and rotating it 180 degrees and putting it back on. sometimes that fixes it right away, if it dont you have a bent shaft. oh the shaft i mentioned at the start is what slides up and down between turning motor and lower unit..
