Tilt but no trim on Mercruiser

[MajBach]

Hi, everyone. Been a long time since I was here - I guess thats a good thing. I have a 305 Mercruiser Alpha 1 on a Maxum 2300. Last year the trim up stopped working but, if I pressed harder, it would go into tilt mode and worked fine. It goes down fine as well. I assume the problem is in the switch. Took it apart today and looks like not a simple job as the switch is a sealed unit and the wires disappear well behind the wall. I just wanted to make sure I don't go through the trouble of ordering a switch, replacing it and then finding out the problem is at the motor. Is there a way of testing it?
Also, what kind of oil goes into the trim?
Thanks

 

[NHGuy]

If it responds when you push the button hard it will also work when the button is fixed. Or did I read you wrong. Sometimes if the up button won't work the trim will. When that happens it's usually that the trim angle sensor is set wrong at the drive.
Those trim pumps can have engine oil or transmission oil put into them. They aren't too fussy.

 

[thumpar]

If tilt works it is not the motor. Most likely the trim switch is bad if tilt works.


ETA: By switch I mean the one on the side of the gimbal ring.

 

[MajBach]

Ugh. I am a little more confused now. To clarify, the little thumb toggle on the throttle control has two up positions; when you lightly press it, it trims up, if you press it hard it clicks once more and tilts up. If you press lightly, it will trim up until it reaches a certain angle and stop. To tilt it more, you press harder to activate the tilt. However, even when the leg is all the way down, you can bypass the trim and go straight to tilt by pressing hard. This is how I am trimming it now, that is, quick presses on the tilt.
The thumb switch has four wires coming from it.
If I understand what one of you is stating, the switch that monitors the position of the trim so as to not allow it to continue to trim up and up and up is possibly busted? Where is this sensor and suggestions on how I can test it?

 

[thumpar]

That does sound like the trim limit switch on the drive is bad. It is on the port side of the gimbal ring at the drive pivot point. On the other side is the sender for the gauge.

 

[MajBach]

That does sound like the trim limit switch on the drive is bad. It is on the port side of the gimbal ring at the drive pivot point. On the other side is the sender for the gauge.

Sorry for the slow response. My boat has 350 hrs on it and hasn't seen a mechanic in 150 of them as it has been parked at a marina during that time. I do as much of the work I can myself but ive been thinking boat stuff is over my head. It was my intention to give it some TLC before putting it in the water this year and a list of minor things to tackle before doing so; like the trim switch. Anyhow, I thought the same thing about doing 100,000mile maintenance on my FJR over the winter and before I knew it, I had it apart down to the valves. So, with new found confidence and the approach that its never to late to learn, I'm tackling the boat head on.
Now understand what you mean by the gimble and the limit switch (couple years ago, the trim position switch went as well).I'm going to leave it until winter when I take the leg right off. Right now I'm doing my first stern drive impeller change.
Expect to be reading a lot from me in the coming months.
Cheers.