'98 Mercruiser Aplha1 Trim

[micah420]

I was reading a lot of the threads on Trim and Tilt for the mercruisers, but didnt come up with one that had the same problem. So thought I would throw it out there.
Lower unit is stuck in the up position. The trim motor runs when the down button is pushed, it lowers about an inch then stops, but the motor still runs. The trailer button lifts the unit back up that inch, but then the limit kicks in. We have checked the connections on the seleniods, there was voltage across the connections and they seem fine. Would the system need to be bled or should I try replacing the selenoid? There was voltage, but only about 7V. If anyone has any ideas, or hint, it would be great appreciated!!!
Thank
--Abram

 

[kbetts]

Re: '98 Mercruiser Aplha1 Trim

Just a guess and easy check, but did you remove the trailering clips on the hydraulic cylinders before trying to lower the outdrive? I did this once at the ramp, I was a little embarrassed.

 

[kbetts]

Re: '98 Mercruiser Aplha1 Trim

Also, welcome to the forum.

 

[Crownline 186]

Re: '98 Mercruiser Aplha1 Trim

The trim hydraulics have a good deal more "push" pressure to lift the outdrive than they do "pull" to lower the outdrive, so I have been told, and that in combination with friction in the hydraulic cylinders will cause this problem.... I have sprayed WD-40 on the extended shafts, had another person operate the controls while I pushed down on the outdrive (boat on trailer) and exercised the system through a couple of cycles.. this usually cures the problem for a while ..... boat is 15 years old and operates mostly in brackish water .... this season have not experienced any "sticking" of the trim hydraulics at all ...... have not rebuilt the two trim cylinders, but have been told that debris does get into the seals and contributes to the problem..... the two shafts do not have any scratches or wear that I can see, so I do not believe that the debris that may be in the seals is causing damage......

 

[wire2]

Re: '98 Mercruiser Aplha1 Trim

Trim cylinders don't really "pull", the pressure is applied to the other side of the piston to push the other way. The hydraulic pressure is the same but the force is reduced a bit because the rod takes up some of the area.

Have you checked oil level?

 

[micah420]

Re: '98 Mercruiser Aplha1 Trim

thanks for your responses!
I originally thought that the fluid level would be the problem considering it was low. Filled that back up, but still no luck.

As far as the trailering clips.....i didn't know that there are some on there. I'm used to outboards with the arm that you lower for trailering, but was curious at the fact there wasn't any for an outdrive on an I/O. Guess there are....can someone direct me as to where they are. I have never used them, that would be great if that was the problem...I would fell really embarrassed if that is the case, but, hey if that fixes it, that would be great!

Thanks!!!
-Abram

 

[kbetts]

Re: '98 Mercruiser Aplha1 Trim

The trailering clips are usually plastic and clip over the two rods on the cylinders on the outdrive. These two cylinders are what raise and lower the drive. They clip on the ground(shiny) part of the rod, and wedges the clips between the rod end and the body of the cylinder. These can only be installed and removed when the outdrive is in the trailer position. This keeps the outdrive from lowering if the hydraulic system bleeds down why you are trailering. Hope this helps.