I have a 1996 40HP Johnson with electric tilt and trim. The hydraulic cycliner is leaking so it needs to be rebuilt or replaced, however the top and bottm pins holding the unit are siezed. I tried to take tham out and failed, so I took it to a dealer who tried and failed. A slide hammer to the top pin will not budge it. The dealer thinks it siezed because it was in salt water.
Yes, removing the tilt pin can be hard. I took penetrating oil and a lot of time with no success. I didn't dare to use a propane torch because of the paint I didn't want to distroy. So I warmed up both ends of the pin with a heat gun (550°C, two of them would be better) for about 20 minutes and got the pin out eventually. The first millimeter is the hardest.
To prevent this happen again I cleaned the pin and holes with sand paper and used some water resistant grease when reinstalling the pin. Now I check the pin for being stuck once a year.