Trim Shift Problem at while cruising

[SadReality]

I have been having a problem getting my prop to move up while at cruising speeds. If I stop the boat, it goes up with no problem. Moving down is no problem at any speed. It does make the sound when I go to trim it, just no movement while underway. It seems intermitten though (once in awhile it works fine). Any suggestions?

 

[Dunaruna]

Re: Trim Shift Problem at while cruising

You'll get a lot of good replies if you include more info such as make/ model/ year.

 

[waterone1@aol.com]

Re: Trim Shift Problem at while cruising

It might help if you post the year, make and model of your outdrive. In general there is a-lot more force required of the trim rams to raise the drive while the boat is in motion than stopped. My first thought would be to check the level and quality of the fluid in the resevoir (make sure it is properly filled and does not show signs of water). Has it been losing fluid (sign of a leak)?<br />Someone else may have an idea how to isolate whether this is a pump problem or a ram problem, but either the pump is not putting out full pressure or the internal seals in the ram are leaking fluid (pressure) from one side of the piston to the other(needs to be rebuilt).

 

[waterone1@aol.com]

Re: Trim Shift Problem at while cruising

I see that Dunaruna beat me on the first part. Something else also came to mind : There could be something mechanical binding (pivot pins, etc.).

 

[SadReality]

Re: Trim Shift Problem at while cruising

OOps, sorry, its a 1994 Mercruiser I/O 3.0L

 

[waterone1@aol.com]

Re: Trim Shift Problem at while cruising

Ok, so we have a merc alpha gen II. Besides what I wrote above about checking the fluid, the next easiest thing to check would be the following: If standing at the back of the boat locate where the trim rams attach to the outdrive closest to you. Remove the plastic caps, then remove the nut on each side. At the other end of the trim rams (closest to the transom) loosen the nuts to get some play. Now pull the rams outward closest to you to disconnect them from the drive. The drive should now be free from the rams. Raise and lower the drive by hand (yes, it's heavy) you should have no problem doing this and it should be free of any binding throughout the range of motion. If it is binding or very difficult to move....let us know, you have a problem. If that checks out, re-assemble what you just took apart, you have eliminated any mechanical binding of the drive. The pump has a spring loaded pressure relief valve....that could be the culprit or as mentioned above it could be in the rams. Someone have some tests to check them (short of throwing parts at it) ?

 

[rodbolt]

Re: Trim Shift Problem at while cruising

the only way to test the hydraulics without tossing parts at it is by using test gauge assy 91-52915A6 or its equivalent.<br /> no other way<br /> up circuit test pressure is 2200-2600 psi and down is 400-600 psi. that and service manual #14. thats about the only way to isolate it without tossing parts at it.