1974 Tilt and Trim Rebuild

jon705

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I have a tilt and trim unit that was removed from a 1974 Johnson 85HP and am trying to finally put it to use. The lines were not connected when I got this so I'm having a time trying to find where everything goes. The schematics available online do not look like what I have. Here are the differences:

Both hydraulic units have inlets at the top and bottom. According to schematic both should have a hole at the bottom but only one should also have a hole at top.

IMG00097-20110411-0750.jpg

The base unit has three rather than two hydraulic lines coming off it. Where does the third go?

IMG00095-20110411-0750.jpg

Also, what is this for? It is not referenced in any of the schematics. It is attached to the end of the rubber hydraulic line.

IMG00099-20110411-0751.jpg

Another question: The pump motor is missing. Is there a replacement available? Anyone know the part number?

Thanks in advance!

--Jon
 
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jon705

Petty Officer 2nd Class
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Aug 26, 2009
Messages
101
Re: 1974 Tilt and Trim Rebuild

I pulled part numbers off the reservoir. Not sure if this will help in determining a replacement part number for the motor but here they are: 104927 and 104183. The hydraulic units have Prestolite stamped on them so I assume the whole setup is Prestolite. Any thoughts?
 

RRitt

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Re: 1974 Tilt and Trim Rebuild

what you have there is power tilt. No trim, just tilt. It goes up under the engine and replaces one of the shock dampeners.
It might even be the chrysler variant of same system. Very carefully check to see if the top tube clears your swivel bracket. I would not be surprised if the tube fitting gets crushed or broken off when the engine lowers. If so, then you may need to figure out a way to plug the hole in top side and drill another one at same height, but pointing directly forward. That and tubing was only real difference between the chrysler and EJ systems through 1980's. The little gismo with rubber hose is a reverse lock release. Chrysler had a latch that gravity pulled into place and locked engine down. The little knob pushes out and releases the latch.
 

jon705

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Re: 1974 Tilt and Trim Rebuild

" The little gismo with rubber hose is a reverse lock release. Chrysler had a latch that gravity pulled into place and locked engine down. The little knob pushes out and releases the latch."

Thank you for clarifying tilt and trim versus tilt only. :) The more I researched and looked at what I had the more I came to think it was tilt only...which luckily is just fine for my purposes.

Where does the little gismo thing attach? It had a piece of wire stuck in the open end. Fluid will not come out of that end? Is this a necessary piece to use the tilt unit?
 

RRitt

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Re: 1974 Tilt and Trim Rebuild

if your engine has a steel latch for reverse lock and you can fashion some holes for that little gismo to push the latch open then you are golden. If not, then throw it away and plug up the side port nearest the front (down facing port is front of pump). Use brass fittings from NAPA. standard 3/16" inverted flare as used on US braking systems.

the upper port is "down". it is a low pressure fitting except in reverse. a right sized ball bearing clamped down by pressure of band collar should do the trick. loosen adapter fitting and remove band collar. A standard drill bit of about 3/8" to 1/2" will give a fine taper on your new front port and a 1/16" to 3/32" should give you a through hole. line up collar with hole and hold in place before putting the adapter back. Tighten snugly but gently. Use a dab of red locktite on collar to adapter threads. Do all this with the top off and piston removed. lightly sand off any internal burrs. Flush generously.

should work great. The tilt head (aka end cap) is old style non-rebuildable. So be gentle with it and don't try to mess with the piston shaft to end cap seals.
 

jon705

Petty Officer 2nd Class
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Aug 26, 2009
Messages
101
Re: 1974 Tilt and Trim Rebuild

if your engine has a steel latch for reverse lock and you can fashion some holes for that little gismo to push the latch open then you are golden. If not, then throw it away and plug up the side port nearest the front (down facing port is front of pump). Use brass fittings from NAPA. standard 3/16" inverted flare as used on US braking systems.

the upper port is "down". it is a low pressure fitting except in reverse. a right sized ball bearing clamped down by pressure of band collar should do the trick. loosen adapter fitting and remove band collar. A standard drill bit of about 3/8" to 1/2" will give a fine taper on your new front port and a 1/16" to 3/32" should give you a through hole. line up collar with hole and hold in place before putting the adapter back. Tighten snugly but gently. Use a dab of red locktite on collar to adapter threads. Do all this with the top off and piston removed. lightly sand off any internal burrs. Flush generously.

should work great. The tilt head (aka end cap) is old style non-rebuildable. So be gentle with it and don't try to mess with the piston shaft to end cap seals.

Thanks for the great advice. Looks like I have some work to do! :D The good news is that I have two of those pistons in case I foul up the first time. Nonetheless I hope to get it right the first time. Will post back when I have an update.

As an aside, I have crossreferenced the pump motor number and came up with 172543 - which is for the motor and reservoir. It "looks" like it will work but I guess I'll only be able to tell if I purchase it and have it shipped. That's the bad of Internet shopping. Unfortunately I can not find it locally. Any better suggestions?
 

RRitt

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Re: 1974 Tilt and Trim Rebuild

Thanks for the great advice. Looks like I have some work to do! :D The good news is that I have two of those pistons in case I foul up the first time. Nonetheless I hope to get it right the first time. Will post back when I have an update.

As an aside, I have crossreferenced the pump motor number and came up with 172543 - which is for the motor and reservoir. It "looks" like it will work but I guess I'll only be able to tell if I purchase it and have it shipped. That's the bad of Internet shopping. Unfortunately I can not find it locally. Any better suggestions?

a lot of J/E and chrysler engines have room for both a tilt and a shock. if you put in two tilts then you can actually do some low power trimming. Just use a brass "Tee" and some copper-nickel tubing. copper-nickel brake tubing won't rust or swell and you can bend & flare it by hand. the flares are a double lap inverted. kent moore makes a little tweo piece die thing you can get off ebay for $10 that does perfect flares easy.

Find an american made trim motor for volvo aq290. it'll work just fine.
No matter who sells it or for what price if it is a new valve body then it is chinese. IMO, you're better off with a rebuilt US than a new chinese. but sometimes crummy is as good as it gets. Try the one you got first and see how it goes.
 

jon705

Petty Officer 2nd Class
Joined
Aug 26, 2009
Messages
101
Re: 1974 Tilt and Trim Rebuild

a lot of J/E and chrysler engines have room for both a tilt and a shock. if you put in two tilts then you can actually do some low power trimming. Just use a brass "Tee" and some copper-nickel tubing. copper-nickel brake tubing won't rust or swell and you can bend & flare it by hand. the flares are a double lap inverted. kent moore makes a little tweo piece die thing you can get off ebay for $10 that does perfect flares easy.

Find an american made trim motor for volvo aq290. it'll work just fine.
No matter who sells it or for what price if it is a new valve body then it is chinese. IMO, you're better off with a rebuilt US than a new chinese. but sometimes crummy is as good as it gets. Try the one you got first and see how it goes.

I'm working on the shock modification at this time but am holding off on buying a new motor just yet. I have an opportunity to trade my boat and don't want to put more money into it until I decide. My boat is not very pretty and is too shallow for my kids' liking. On the plus side she's mechanically sound. The potential trade is a little bigger and still mechanically sound...the point that has me on the fence is she's a bit outdated. :) I'll know in the next day or two whether the trade will happen and if not will purchase a new pump motor to complete the project.
 

jon705

Petty Officer 2nd Class
Joined
Aug 26, 2009
Messages
101
Re: 1974 Tilt and Trim Rebuild

One of the shocks has the fitting in the correct location facing forward - no modification necessary. If I decide to add the second shock for low power trimming I may need to modify it but eyeballing it looks like it may work un-modified as well. Spent the morning cleaning the crud out of the lines and reservoir. So she's ready for the new motor.

I'm taking one last measurement before ordering the motor. I found the Volvo pump motor that you recommended. The only difference between that one and the one I stated above #172543 that is listed for Johnson/OMC/etc. is that the driveshaft slot on the Volvo is .2mm wider.
 
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