Tilt/Trim motor bogs down

[Masonmobilemarine]

I have a 2005 F225 tilt/trim unit I'm in the process of rebuilding. It had 7,000 hours on it (commercial guy) and operated fine, but when I opened it, it was just filthy. So I stripped it down completely. Removed all the rams, gear pump and the pipe on the top. Flushed it all out in a parts cleaner and replaced all the orings/seals etc. I have done many units this way with no issue.

I was testing it out and it seems off. It would go up on its own, but when going down the larger tilt would go down perfectly, but once it hit the trim rams it would just STOP. It was like the motor bogged down and just wouldn't move, like there was too much load on the motor. I could put a battery charger on the battery I was using and crank it up to starting 200amp and it would move it, but still very bogged down (motor didn't get hot). If I released the manual release screw...it would actually work again and pull the trim rams down without any force, but I could push them down as well. Once they were all the way down again, if I closed the manual release, it would bog the motor down again and it wouldn't run.

I took the motor off, and turned the "down-release" screw half a turn out so it would be "looser" and ran it up and down again. This time the rams would pull in by themselves and the motor would continue to run after the rams were full retracted...which is what it should do.

The motor seems to be running slightly different than what I'm used to once it gets to the trim rams, but it's working as it should (and without weight of the motor on it). Anybody else experience anything like this?
And I did also try to use another gear pump that I know was in good working order as well, same thing.

It is bled and everything is good otherwise.

[zenoahphobic]

I’ve never worked on these, but it sounds to me there are locking valves that have been reversed (if that is possible) or have been put together wrong or are stuck.
Can you remember what components that you replaced? I always take plenty of pictures as I dismantle and then compare the old bits with the new bits before reassembling with things as fiddly as these.
Rereading this, your last statement seems to say that this motor does the same on a different pump assembly. At 7000 hrs I’d imagine this motor if still the original may be “worn” out and probably needs a good check out. It could be full of carbon from worn down brushes that are electrically bridging the commutator making it weak. I don’t suppose you have another known good motor to test with?

[Masonmobilemarine]

I was able to get it working last night. I used yet ANOTHER gear pump assembly and it started working fine. I did use another motor as well just to check, and even had a battery charger on 40amp to give it extra juice.

Anyways, with the 3rd pump it works fine now. I was having to rebuild 3 of the exact same thing. When the first pump didn't work, I opened it up to check it and it seemed fine. Then I rebuilt it but it was kinda wonky. So tried the 2nd one...same thing. Odd.

Got it going though. I thought I had something stuck in the metal pipes/lines that I couldn't get out even in the parts cleaner. Unfortunately if youre in salt...you just simply aren't going to get that line off without breaking things beyond repair "most" of the time.

Looks like I need to do some fiddling with the gear pump assemblies now though. Odd.

[Masonmobilemarine]

Well, I was able to get it to work properly...ish.

Granted now Im still sort of stuck.

The motor goes down perfectly fine. Going up, the trim works perfect, but the moment it gets to the tilt...it won't go up any further. Motor still runs as it should, but doesn't have the "Umph" to actually go up. If I use just 1 hand while holding the switch, it will come up. If I get it about 3" up from the trim rams, it will have enough power to pick itself up. No leaks or anything still.

Really stuck on this one.

[TownsendsFJR1300]

I gather properly bleed out and fluid topped off?

Low fluid will make it act up..

[Masonmobilemarine]

Oh yes, properly bled, plenty of fluids.

[Bluefish]

Have you focused on T/T unit to much? Have you check for binding on the motor pivet it self, hard greese rust ect.

[Masonmobilemarine]

Blue, none of those issues are at play here. Have considered, inspected and it's not the situation. I have even used 2 different tilt rams.

[Masonmobilemarine]

Update:

It is working now. I'm really not sure what I did to "fix" it though. I tore it all apart this time, literally nothing left of it that could come off, I even removed the filters UNDER the gear pump. I think I had a blockage in one of the hard lines, but being in the gulf coast with higher salinity than even the oceans....I was very scared to remove those lines as its almost always a guarantee that they will strip the aluminum out of the body. Took a torch and bees wax and spent 30 min just removing one nut, but it came out.

Ran everything through the parts washer then took 100psi with a rubber nozzle and BLEW through everything.

Put it all back together and bench tested it. The trim rams wanted to act like they were locking up, but manual released it and pushed them down and got rid of some air. Was trying to air lock at first. After a good bleeding, all is well now.

[99yam40]

thanks for the update, it is a shame you did not find something that you could put your finger on that was the problem

[Masonmobilemarine]

thanks for the update, it is a shame you did not find something that you could put your finger on that was the problem

I suppose sometimes a thorough "repair procedure" is simply the "fix" in itself.