Type 1 Power Trim Installation help

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Well managed to find a nice used power trim unit for my 1970 Merc 800. Its the two ram type with 4 hoses and a remote pump.

Question is, how do I install it onto the motor? The motor is off the boat right now.

Does anyone have directions or maybe even a copy of the OEM instructions? I assume that the system needs to be bled once its all together again. What is the procedure for doing that?

Any help is appreciated.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Type 1 Power Trim Installation help

Ed thanks for that link. I did get the complete unit, infact its still mounted to another motor. I have two identical motors, both mounted on stands. One has the PT but is non-running, the other runs but does not have PT. Want to remove PT from one and install on the other.

A couple questions still.

Can I uninstall the PT from the donor motor and reinstall it on the recipient motor WHILE they are mounted on stands? Don't want the motor falling to the ground unexpectedly. That would make for a bad day.

Found two brown wires routed with the hydraulic lines running to the starboard ram cylinder. Would these be for trim position sensor? Can't see where they end up inside the housing.

What fluid do I use and how do I bleed the system?

Sorry for so many questions but I have searched extensively with no luck.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,124
Re: Type 1 Power Trim Installation help

You may indeed swap the PTT unit with the motor on the stand. emove the two 1/2" fine thread bolts from the shocks and remove them. Now bolt on the PTT brackets to the top shock mount. Now bolt the PTT cylinders to the bracket and lower shock mount. The bracket takes a 3/8" fine thread bolt and locknot. The two brown wires are from the trim limit switch on the starboard trim bracket. You can ignore these as they likely dont work anyway. Fill the trim pump with 5W-30 motor oil, or dextron III auto trans fluid, depending on what was used last. Dont mix the fluid. You need to bleed the trim cylinders. I have posted the procedure many times.
 

*EdC*

Senior Chief Petty Officer
Joined
Oct 31, 2007
Messages
661
Re: Type 1 Power Trim Installation help

Moody Blue,
I think Chris has answered your questions. He is very knowledgale and has helped me out in the past. If I were to add anything.... Consider rebuilding the cylinders. It would be a shame to get it all together, only to find out they had bad seals or "o"rings.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Type 1 Power Trim Installation help

Guys, thanks very much for your help.

All I need now is to find the time to get it done.

Chris, you are very busy on these forums. Sure do appreciate your time and knowledge.

I just finished reading the procedure for filling and bleeding the system. Very clear and straight forward.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Type 1 Power Trim Installation help

Finally getting the time to finish installing the PTT on the good motor.

Have the lower unit off to change out the waterpump assy and I got looking at the reverse lock system. From what I can see, I think I need to remove the components for the reverse lock system if I install PTT. Is that correct? THe two systems could interfere with one another, yes?

Do I remove everything ie., clamps, spring, activation rod, shift shaft cam etc etc?

Thanks in advance.
 

*EdC*

Senior Chief Petty Officer
Joined
Oct 31, 2007
Messages
661
Re: Type 1 Power Trim Installation help

Finally getting the time to finish installing the PTT on the good motor.

Have the lower unit off to change out the waterpump assy and I got looking at the reverse lock system. From what I can see, I think I need to remove the components for the reverse lock system if I install PTT. Is that correct? THe two systems could interfere with one another, yes?

Do I remove everything ie., clamps, spring, activation rod, shift shaft cam etc etc?

Thanks in advance.

MB
Yep all of that goes..... You may want to consider adding a tilt stop strap.
For this, you will need a new rod and sleeve. Believe it mounts in the same holes as the reverse lock out assembly. Here's a link to better see what I'm talking about.
http://www.crowleymarine.com/mercury_parts/1991/170.cfm


Hope that helps
Ed
 

Moody Blue

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Joined
May 24, 2004
Messages
3,136
Re: Type 1 Power Trim Installation help

Thanks Ed, that helps a lot. Thats the best picture quality I have seen.

What is the reason for the tilt stop strap. Will the rams not just bottom out at the end of their travel? Is there a possibility of over travel?

From the illustration its not clear where the strap attaches. Can probably figure it out when I take a close look at the motor tomorrow.
 

*EdC*

Senior Chief Petty Officer
Joined
Oct 31, 2007
Messages
661
Re: Type 1 Power Trim Installation help

MB
The tilt stop strap will keep your motor out of your cockpit should you hit something submerged...especially at WOT:eek:
The strap has a loop sewn onto each end. Once the lockout assembly is removed and you have the new rod and sleeve, slide one end on, wrap the strap up around the horizontal transom bracket support, and down back to the rod, slip the other end on the rod/sleeve.
Lots of words ..but it's pretty simple. Check out parts 87 through 91. There is also a foam cushion that goes on the transom bracket. It protects the strap from wear. Putting them on correctly is alot of effort. On the re-fits I've seen ..They are sliced length-wise and taped on. Hope that helps!

Regards Ed
 

Dustin0330

Cadet
Joined
Jun 29, 2009
Messages
25
Re: Type 1 Power Trim Installation help

Sorry to bring up such an old thread but Im currently intstalling PTT on a 72 Merc 800 and I've ran into a few problems.
The tilt stop pin and sleeve I have is too big to go in place of the lockout assembly and there's no other place located on the swivel bracket where I can install the pin.
Did merc offer a smaller diameter pin and sleeve?
 
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