Tilt Trim Exchange

[Donewright]

Greetings,

I have a 1978 150hp that has an older tilt/trim unit with the external hydraulic pump. I also have a tilt trim unit from an 80's 150hp engine that has no external system. Now the main difference in the two appears to be the width of the transom mounting holes. The '78 is narrower than the 80's mounting holes. But the swivel arm mounting yokes look to be identical (About 3" on center between holes and 17 1/4" between yokes).

My problem in exchanging the two units is that the shift shaft runs down the center of the mount. This prevents me from just removing the four bolts and swapping the units. I don't want to have to separate the midsection from the upper unit because I don't want to have to replace the gasket that lies between them. I see that there is a roll pin in the gear shift lever that is attached to the shift shaft. Is is a good idea to knock the pin out and then pull off the bottom unit allowing the shift shaft to come out the bottom?

Here is a picture of the roll pin in the shift lever.


Thanks for any advice !

 

[Donewright]

OK. I have separated the lower unit and knocked out the roll pin. The shift shaft came right out.

I removed the lower two bolts off of the swivel arm and tried to get the top two, but they just keep turning and don't appear to be releasing. Is there a catch or something that I am missing?

Perhaps #30 nut is spinning?

 

[Donewright]

So it appears that I need to remove the mid-section from the power unit. I have removed 4 nuts and 3 bolts, but the mid-section won't budge. Any ideas?

 

[Donewright]

Update:

WRONG WAY: I was trying to separate the mid section from the spacer that sites between the power head and the mid section.

CORRECT WAY: Remove the 4 nuts from the mid section. remove 6 nuts from the spacer. Both pieces come off as one unit. Once they are removed, there are two bolts inside the spacer that connects the mid section to the spacer.

The '78 mid section fit perfectly on the 80's model tilt trim! Awesome! A little soap and water and it will be good as new!

 

[Donewright]

OK. I have the 3 of the 4 gasket surfaces clean. I still have a bit of work to do on the powerhead surface. The gasket kit has been ordered and I'm just awaiting it's arrival.

 

[Donewright]

The mid section is cleaning up well. I just wiped it down real quick. It still needs a good soapy wash and wax.

 

[Donewright]

The TT transplant was a success!