Re: lower unit for 1987 Johnson 30HP
30 hp lower end gears are notorious for failure. They seem underengineered according to our mechanics. We have gone through 2 in 3 months for one of our customers that runs a 16 ft trihull hard. Its too much for the little pinion gear. Recommend a rebuild. Parts are cheaper at Pro Marine in Florida. A gear set is probably what you need. Keep it in mind- you haven't got a robust rear end.