Merc 70 tilt/trim unit - rebuild or replace? PICS

[Grant Brown]

I've been working on my Merc 70 tilt/trim unit.
I got the thing apart this afternoon and it is full of salt water. Looks like the O-rings on the bottom of the armature plate leaked and it got into everything. The armature is seized in the motor housing and the oil came out dirty and stank like a tire inner tube.
There was corrosion on the machined area on top of the pump where the motor bolts on.
None of the rams will move by hand with no oil or pressure in the system.
The main tube has been fixed before and now the retainer and washer are popped up away from the O-ring seal on the shaft.
My gut says this will be a PITA to fix properly especially if the inside of the ram tube is corroded.
The boat is not worth more than $3500 locally and I do not want to do this again any time soon.
Rebuild it or replace? What do the rest of you guys think?
Pics below

Thanks,
Grant

 

[MaggieRose]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

Does the motor spin freely, without any bearing noise? Run any electrical checks on the motor (was it working OK before you broke it apart)? If the motor checks out OK, and the pistons and rams are in decent condition, you could get away with just replacing the motor seals and a hydraulic rebuild kit.

 

[Grant Brown]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

The motor is seized (the armature won't turn in it's housing).
The rams were rebuilt about 3 years ago and it seems to me the main shaft was rough and had to be polished at that time.

Thanks
Grant

 

[MaggieRose]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

Replace the unit. A rebuilt unit wil be almost half the cost of a new one.

 

[TriadSteeler]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

Time to cut bait.

Do you Ebay?

Seriously though, I have seen dozens of those units on Ebay.

 

[Grant Brown]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

That's what I am thinking. Will the style with the aft fill work? Mine is port side fill through the transom bracket.

Grant

 

[mariner45hp]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

how did u up loaded the pics? i am trying to up load my pics and post but i can't.

 

[Grant Brown]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

You start a post then at the bottom of the page there is a button called Manage Attachments. Click it and then a window opens so you can browse the files on your computer. Find the photos you want to attach, then click upload.
You will be able to see the names of the files listed above the Manage Attachments button. Close the window, then post the message. You can preview it first to make sure you got the right photo by clicking the Preview Post button.
A picture is worth a thousand words... Hope this helps!

Grant in Vancouver

 

[MaggieRose]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

I also have port side fill. Made a jig with a 3/8' clear poly hose, put it on the end of a squirt bottle. Gets the hydaulic fluid right in there.

 

[mariner45hp]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

i did that and i keep getting up load filled.

 

[Grant Brown]

Uploading photos

Uploading photos

Maybe your pictures are too large. Resize them to something like 800x600 pixels and try again. The smaller picture size will allow people on slower connections like dial up to see the picture without waiting, and the owners of this site don't want all of their server space used up with photos.
Other than that I have no idea why it's happening.

 

[Grant Brown]

Re: Merc 70 tilt/trim unit - rebuild or replace? PICS

I also have port side fill. Made a jig with a 3/8' clear poly hose, put it on the end of a squirt bottle. Gets the hydaulic fluid right in there.

Thats a very good idea, I might try it myself.