Mercruiser Trim Pump Problem

[BillK2632]

Last year, all of a sudden, my power trim started making a different sound. A definite louder, raspy sound, more so when going up. It still works fine, goes up/down at the same speed etc, just makes this louder sound. Last year after it started making the noise I changed the fluid, but no difference. When changing the fluid (I used my oil extractor to suck it out of the reservoir) I noticed it sucked up what looked like some gunk that had formed in the tank over the years. I have checked the power across both solenoids and made sure all the connection are tight, all that looks good. My next thing is to remove the pump and clean out the reservoir - I am thinking that "gunk" could be restricting the pump from picking up the fluid, just a guess though. Anyone have any advice?

 

[Skip Boyer]

Defiantly sounds like the pump suction could be restricted, especially since you found contamination in the fluid. There is most likely plenty more in system.

 

[BillK2632]

So today I decided to take the trim pump off and figure out what is wrong. First the reservoir was very dirty - years of gunk form the fluid, so I got that all cleaned up. Didn't hurt to do, but I don't think that was the problem. When I separated the motor from the reservior, there is a coupler that the motor shaft fits in to spin the pump. The coupler is broken. The pump still works and the motor is fine, going down it sounds normal, but going up it makes the louder raspy sound. Either way I need replace it, not sure how it still works with that broken. It looks like you can order them, but has anyone had that happen?

 

[BillK2632]

Just a followup - ordered a new coupler - put it in today and the trim works like new. Smooth and quiet.

 

[Tones1975]

Just a followup - ordered a new coupler - put it in today and the trim works like new. Smooth and quiet.

Just wondering if you have the part number for the coupler?

 

[BillK2632]

I forget where I ordered mine, but this is the part:
Mercury Mercruiser New OEM Trim Tilt Pump Motor Drive Coupler 803852 89493 (leadersrpmshop.com)

It's one of those little parts that is stupid expensive for what it is -- but if it's broken you need one and have no choice but to pay up.

 

[Scott215]

Thank for the info

 

[Tones1975]

I had a very loud rattling type of sound while running the trim pump up and down. The boat came with a used spare trim pump and motor; so I swapped them and the new one just clicked with no movement. I pulled it back out and found that the motor was good but the pump was frozen. I then looked at the original pump and motor and discovered the pump was good and motor had a worn out bushing resulting in a wobble in the shaft, causing the rattle. Used the good motor off of the spare pump and was able to put it on the original pump. Installed the new assembly and works great.
Long story short; it was a worn out bushing in the motor.

 

[Scott215]

I have read about that bushing before causing that issue and thank you again