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Mercruiser 4.3L Trim Issue

P

Poggemiller

New member
I have a 1996 Searay with a 4.3l motor and Alpha 1 drive. My issue started out that the trim motor would not raise. By tapping the motor it woulod start working again. A mechanic at the marina told me to have the motor rebuilt. I pulled the trim unit out of the boat and had it repaired at a local electric motor shop that the mechanic recommended. I was told there were no repair parts available and I would need to replace the motor. So I have a new electric motor. I installed the new unit and filled it with Dexron 2. The unit went up and down fine on the trailer. However, under power it would not trim up. I needed to slow down to trim up. I spoke to a mechanic at the boat repair shop and he told me that the pressure relief valves were out of adjustment. I removed the unit and he replaced all of the valves and the shuttle. He advised me to switch to 10W-30. I bled the Dexron out as best I could and have refilled with 10W-30, ran it up and down several times and topped off the fluid. Just put it in the water and it still does not trim up while under power. This sounds like air in the system, but I thought this setup was self purging by running the unit up and down several time. Is there a special process for bleeding the hydraulic lines? I would appreciate some help on this.:confused:
 
Merc recommends purging by fully raising the drive leg up and down from six to ten times. That will remove all the air from the system.

Rod
 
could be wrong but merc recommends power trim fluid or I think dextron 3, volvo uses 10w-30, why? don't know. also did you check the manual release valve to make sure it was tight?
 
It's interesting that you say it sounds like it's assembled backwards. When I reinstalled after having the motor replaced, I hooked the hoses up and the unit went up when I pressed down. I thought I had crossed the hoses. Can wires be crossed to make the motor run backwards?
 
Reverse the blue and green wires on the solenoids and the hoses and it will probably work correctly.
These units deliver unbelievable amounts of pressure to push the drive up and barely any pressure to bring the drive down.
 
Blue is up (color of sky)

Green is down (color of grass)

Black is ground.

These are the motor wire colors from the motor to the two solenoids.
 
I took a picture before I started this whole project. I confirmed that the hoses needed to be reversed to work properly after the motor was replaced. However, the wiring is correct - blue on top and green on the bottom. I assume this means that the wires are reversed inside the motor. I can't get to this for the next few days, but at least I've got a solid lead.

Thanks for your help!
 
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