OMC Outboard sticks in down position

I have a 1984 seaswirl with a 3.0 OMC outboard. I can lower and raise the drive while parked at the house. after getting underway and driving around a bit the outdrive will not raise. Quite a scene at the boat ramp, you know. Anyway I found that loosening the 3 bolts on the cover of the worm gear allows some sort of pressure to release and then the outdrive will raise right up. I can't find anything that says that can be adjusted, or spacers added, or what not. What could be causing this to occur? Once it frees up the motor works it just fine raising and lowering so it's not the electrical.

Thoughts? :idea:

 

Hey Art

Your trick with the bolts worked for me to get my outdrive up.Have you came up with the answer to your problem? Hilt

 

Stuck Outdrive

Haven't found any answer as to why this is occuring yet. I thought maybe there is some sort of a "seat" that keeps the outdrive from overextending down and maybe that is why it becomes "stuck" .

I have even looked for wear marks on the cover thinking that there was some sort of a washer or pad that may have worn away that is causing this.

I cannot generally get this to duplicate the problem parked in the street lowering the drive all the way down. Only after getting u/w will this occur! If you find something before I do, pls post it

 

Sounds like a wear issue to me. You mentioned worm gears, so I assume this isn't hydraulic? I'm not a boat mechanic, but on the steering box of my car (also a worm gear unit), there is an adjustment bolt to account for wear. You know how old cars have a lot of play in the steering? Most of that can be adjusted away.

Another possibility is the worm gear may just be worn at the edge, or the part that engages the worm gear, and the pressure from the engine is able to force the lip of one gear over the other. It's still basically a wear issue.

Whether or not you can adjust the clearance of your worm gear depends on your unit.