I have no more ideas left

[MR nova @#25]

I have a pair of mercruiser pre alpha outdrives, that were working fine. Seven months ago, the Port motor, port trim cylinder had a crack in the outer cover.It was replaced. The outdrive would only go down 3/4 of the way, it had to be pushed down to its lowest point. Long story short, All the hoses were replaced with new ones, the manifold connects the hoses from the outdrive to the trim pump was replaced. Both trim tubes were rebuilt and all rhe O rings were replaced.with that said the outdrive only goes down 1/2 way now.
The last thing we did, was swap the port trim motor with starboard trim motor. The outdrive still goes down 1/2 way. This is the only piece of the puzzle I haven't touched. Its been bled Multiple times.

 

[kenny nunez]

When the rams were rebuilt did you get the most forward piece out of the tube? That is the one with the smallest “O” ring which is about 1/2” o d ?
Where did you source the “O” rings? The only place where you might find a perfect match is an aircraft supply location.
The real problem is that the correct kits are NLA. I found the 25-60342A2 seal kit on e bay, however they are $50.00 each.
From the picture you have pre 75 drive system with the reverse lock valve.
If you plan on keeping your current drive platform the only thing I can suggest is to replace all the rams with the Alpha series along with the hoses and mounting hardware. Hopefully there is a boat salvage yard in your area that will have some used ones.

 

[MR nova @#25]

When the rams were rebuilt did you get the most forward piece out of the tube? That is the one with the smallest “O” ring which is about 1/2” o d ?
Where did you source the “O” rings? The only place where you might find a perfect match is an aircraft supply location.
The real problem is that the correct kits are NLA. I found the 25-60342A2 seal kit on e bay, however they are $50.00 each.
From the picture you have pre 75 drive system with the reverse lock valve.
If you plan on keeping your current drive platform the only thing I can suggest is to replace all the rams with the Alpha series along with the hoses and mounting hardware. Hopefully there is a boat salvage yard in your area that will have some used ones.

Thanks for the reply, replacing the reverse lock solved the problem. The rams were rebuilt, including the Orings.