Lifting '75 OMC 165 Inline 6 & Repairing Electric SelecTrim

gryhnd

Cadet
Joined
Aug 10, 2007
Messages
22
Re: Lifting '75 OMC 165 Inline 6 & Repairing Electric SelecTrim

Ever since we bought the boat 5 years ago, the SelectTrim gauge never registered. It was always stuck in the middle, until about a year ago when the needle suddenly disappeared. I figured it had fallen off.

Since everything trim related is removed right now, I yanked the trim position sender unit (see Ch7, Pg13, pic 15). It had some corrosion from the aforementioned water infiltration. The shaft for the potentiometer was frozen, and the attached gear was slipping.

After removing the gear, I scrubbed the pot down with some ECTRA-MOTIVE, including letting some (hopefully) run down the shaft and get into the inside.

I did this a number of times, let it dry for a while, then followed up with several drips of dielectric grease...again hoping they'd get inside. A gentle grip with a wrench, twist, and I got it unstuck. Slapped the multimeter on it, and while it's a bit jittery, it seemed to work. Hooked it up to the boat again, and imagine my shock when the trim needle MOVED.

This keeps getting better and better. I'm afraid something is bound to totally screw up somewhere along the way..

One thing as a tip to future viewers: the pot has a defined range of motion for the shaft, and it's not very much. Be careful if you are putting some muscle into what appears to be a stuck sender...it could just be at the end of its travel.
 

gryhnd

Cadet
Joined
Aug 10, 2007
Messages
22
Re: Lifting front of '75 OMC 165 Inline 6 (Chevy)

Re: Lifting front of '75 OMC 165 Inline 6 (Chevy)

Any suggestions on my other question about how much grease to put back in the whole shebang when I reassemble? Pack it full? Or just grease up all the components and then fill the bottom of the jackscrew case?

Thanks

BTW, I did look at the manual, but given what I've seen, and what Howard Sterndrive said above, I'm not convinced it's enough: "Lubricate the SelecTrim unit with Suno- plex EP 992 using a hand gun. Work the gun about five to eight good strokes at the bottom of the lube fitting."
 

gryhnd

Cadet
Joined
Aug 10, 2007
Messages
22
Re: Lifting '75 OMC 165 Inline 6 & Repairing Electric SelecTrim

I picked up the new thrust bearings first thing this morning.

Capeway had to order 10 of them, although I only needed two. They only charged me for the shipping it took to get them to their shop and not all 10, thankfully. So if anyone else needs 3/4"O.D., 5/16"I.D. thrust bearings, Capeway has 8 in stock for $4.00 apiece.

With the new bearings, I had the entire mechanism reassembled in about 30' and ran a test off my battery. Everything seems in order now, so hopefully this weekend (or tonight) I'll get the whole thing reattached to the engine.

Then, fingers crossed.
 
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