Mercury Trim/Tilt problem

[MJBennett.FL]

I have a 40hp Mercury which the trim motor has recently been replaced. It seems to trim down fine, trim up fine, but when it goes to tilt up, it is weak and needs help? It does not seem to be leaking or losing any trim fluid. Possibly, the trim ram needs to be rebuilt? Any suggestions would be greatly appreciated!

Thanks,
Mike

 

[MJBennett.FL]

Re: Mercury Trim/Tilt problem

Is it possible that it could be the bushing's inside the trim motor bracket and the ram and motor mounting holes? Worn out maybe and when it gets the full weight of the motor while tilting it is pushing against the housing and binding?

 

[Texasmark]

Re: Mercury Trim/Tilt problem

Will look up the bleed process for a 90....should be the same.....may be as simple as that.....just a minute while I access the manual..........

Ok, I just located the section "Bleeding the power trim unit":

To start with, you need to remove the fill plug which is/should be a plastic plug (white nylon painted black on the outside like the pump) about the size of a US nickel coin, below the round (motor) part of the trim unit on the upper part of the square area. There is another screw below this one and 90 degrees away that is the manual release valve....if your unit is working as it is, that valve is probably closed as it needs to be for this test.....that is snugly CW.

Fill with Quicksilver PT fluid (clear), or ATF if fluid is red...stick a Q-tip in the hole and see what color the oil is until oil is even with the bottom of the threads.....This is a horizontal plug so the bottom of the threads is easily visable from the point of how much to fill.

Put the plug back in and run the trim/tilt up and down as far as it will go several times. Pull the fill plug back out and check fluid level. If not where it was, put more fluid in till it is back to the bottom of the threads.....continue doing this until you can go from max down to max up and after the exercise, the fluid is still at the bottom of the threads.

If this doesn't solve your problem, come back on here.

HTH,

Mark

 

[RRitt]

Re: Mercury Trim/Tilt problem

is this your system?

http://www.boats.net/parts/search/Merc/Mercury/1998/1050302UD/POWER TRIM/parts.html

The problem you describe is fairly common on this style system. It is caused by the tilt relief valve assembly. Part #4 in the diagram.

 

[Texasmark]

Re: Mercury Trim/Tilt problem

Butttttttt nothing wrong with trying the inexpensive route first????? But if that fails you have the backup plan.

Mark

 

[MJBennett.FL]

Re: Mercury Trim/Tilt problem

Yes that is my system, the relief valve assembly will be here tomorrow afternoon, so before that I will try and bleed the system, thanks for the help! I will keep you posted on what the fix could be.

 

[MJBennett.FL]

Re: Mercury Trim/Tilt problem

Okay I replaced the Relief valve assembly which was missing two o-rings, so that helped but it didnt seem to fix the problem. So i stepped back and looking at it while it was going up and down, and instead of the motor turning around the tilt tube, it was locked up and turning on the motor mounts. So long story short after pulling off the pulling platform, hanging the motor, taking the steering out, a ton of heat, 3 hours of hammering, a new tilt tube, spacers, and nuts, the problem is fixed and it trims and tilts better than ever. Thanks again for the advice.