Trim whining/ratcheting noise after replacing trim fluid

[csjoyce3]

Hello,

Thank you in advance for any help you can offer. I have a 2001 Mercruiser 4.3L w/ alpha one outdrive. Sterndrive unit serial number is 0L923910. The problem is that the trim motor is now making a louder than normal ratcheting type noise when trimming up (including trailer up).

I'll list things chronologically. A few months ago, the boat was run aground onto sand at 20mph (enough to compress the outdrive trim cylinders) and the trim system has been acting up ever since. First I've been having trouble with the outdrive trimming down since then. It would consistently hang up before the initial down trim of the day, then after tapping the down trim a few times, it would start down and work fine the rest of the day. It would make a single click noise similar to a car starter with a weak battery.

Then today, I was unable to get the outdrive to trim down at all initially. The trim fluid looked dirty so I drained the reservoir and refilled with 25w-40 motor oil (even though manual calls for trim fluid then 10w-30 or 10w-40 oil). Finally able to get outdrive to trim down and it immediately started making a loud whining/ratcheting noise but only when trimming up or trailering.

Hoping to eliminate the easy stuff first, I cleaned significant corrosion off all the trim unit terminals. Also, I drained the reservoir again and refilled with 10w-30 after canceling the boat day and making the drive of shame to the store to buy some. Neither of these things worked as the noise is still there. Hopefully cleaning the terminals will at least eliminate the issue of the outdrive not trimming down initially..

I've got some ideas, but nothing concrete. Any advice is appreciated, thanks a lot!

 

[dingdongs]

Re: Trim whining/ratcheting noise after replacing trim fluid

remove aft pin nuts shaft for cylinders and release nuts on forward shaft.pop cylinders off drive and make sure you can lift drive fully up and down as it should be moving freely.make sure pivot points are getting lubed yearly on the drive.

 

[csjoyce3]

Re: Trim whining/ratcheting noise after replacing trim fluid

Pivot points have been regularly lubed, outdrive moves freely.

Now I'm suspicious of a pressure relief valve and am going down that road. Suggestions?

 

[dingdongs]

Re: Trim whining/ratcheting noise after replacing trim fluid

it sounds to me as if the solenoid is not getting full load to the pump to make it work.have you tried bypassing the solenoid by briefly taking a 12v+ve from the battery directly to the blue up or the green down to see if its the solenoid being faulty.you may have a different solenoid for each action and only one may be faulty in which case a swap may prove a faulty one.

 

[csjoyce3]

Re: Trim whining/ratcheting noise after replacing trim fluid

I have not but will try that if the pressure relief valve doesn't work. Installing tomorrow. Just a theory but I'm thinking that this noise is from filling reservoir with 25w-40 instead of 10w-40. The noise is from the trim system area (not cylinders) and it started immediately after switching to the more viscous oil. More viscous oil should equate to a higher pressure and higher pressure could blow out the pressure relief valve.

Also, based on another post I read on here, the ratcheting noise could be the pressure relief valve releasing pressure repeatedly and rapidly. Sounds good anyway... Ideas?

 

[csjoyce3]

Re: Trim whining/ratcheting noise after replacing trim fluid

Well that didn't work. Replaced the up trim pressure relief valve and no change. I had in mind that it would be a one time pressure disc or something, but it's a spring and ball type system so not one time.

Ya know, the up trim sound was normal the first cycle but all the rest were back to the loud ratchety almost grinding noise. Hard to describe sounds, but anyone heard something like this?

Will swap the electrical leads next to test the servo.

 

[csjoyce3]

Re: Trim whining/ratcheting noise after replacing trim fluid

Swapped the trim motor leads and its still making the loud noise when the outdrive comes up (trim button pressed down), so the solenoid seems good. Also bypassed the up solenoid with a jumper and still making loud noise.

Trimmed motor 3/4 down (most I can go in parking spot), detached a front cylinder hose and trailered trim switch to drain system and reservoir. Refilled and repeated, refilled. Made the proper trim noise when doing this. Reattached front cylinder hose, trailer trimmed and making loud noise again.

I'm beginning to think the trim motor itself was strained from the more viscous oil. Could only be making the noise when trimming up due to the increased load of raising outdrive vs lowering.

I'm quickly running out of ideas, would appreciate a second opinion and/or sanity check, thanks a lot.