OMC electric shift convert to mechanical shift

Status
Not open for further replies.

Redrig

Master Chief Petty Officer
Joined
Oct 13, 2009
Messages
849
I am always looking through my local classifieds for OMC stuff. I have found a boat with a cracked block that has a full mechanical shift outdrive on it that the owner is parting out.

I have a 77 electric shift that is a low profile unit powered by a ford 302 with cable steering.

I have heard that I can swap the mechanical shift lower onto my electric shift, I am not familiar with the mechanical shifts too much but I understand that they use a converer box to help with shifting, so obviously I will need that as well.

a couple of questions.

can I use my existing upper, or do I need his upper ? what about intermediates, can I keep mine?

Do gear ratios matter ? his is a v8 and so is mine.

Any other items that need to be swapped out to make this happen ?


the only reason why I am pondering this is that my boat is relatively solid, the engine runs great, no probs with intermediate or anything like that, it is only the electric shift lower that worries me and has given me problems in the past. I broke a forward spring a few years ago and that really ruined my vacation, literally.

I have a boatload of electric shift parts, an extra lower, 6 props, ect. that I could sell to make this probably not a big cost at all.

anyone done this with any tips or advice they can share. Thanks
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: OMC electric shift convert to mechanical shift

I switched my electric shift to the hydro-mechanical drive back in 1979 and never looked back. After all these years with many hours of heavy use, I just had the drive gone thru a few years back, for general principals. It was probably good that I did because the water pump shaft splines were getting pretty worn.

...and yes, you can keep your existing intermediate housing. Make sure you get the the shift cable, the shift converter box and the shift/throttle control with all it's cables. It might be a good time to change the ball gears as well. T'would be good to start out with a new matching pair. You will also have to enlarge the hole thru the intermediate housing to accommodate the larger diameter shift cable. Then seal it with a stout sealer. The later IM housings had a seal and a cable retaining clamp which yours will not have.

If I had it to do over again, today, I MIGHT hold out for the later full mechanical drive and all it's associated components. I do however like the hydro-mechanical unit because you do not have to fuss with the shift interrupt system.

Oh, and one thing I forgot. Beware that your intermediate shaft and coupler that bolts to the flywheel have the finer splines. You do not have to remove them to do the drive swap and of course you would have to pull the engine to get to the coupler. Mine, with hundreds of hours of pushing a 20 footer and pulling many a skier was pretty worn. I replaced them both with the latter, larger spline set up. I had my engine and IM housing out to do a floor and bilge rebuild.

This might also be a good time to disconnect your TruCourse steering drum from the intermediate housing, lift it high in the air and shoot a good lubricant down the double cable way while repeatedly turning your steering wheel back and forth, lock to lock. After 30 years this made a huge difference in the reduction of my steering effort.

Gear ratios do matter but I think you would be fine going from V8 to V8. It is my feeling that you should swap the whole drive. Not expert enough to know if you could just use the lower. I do know that the housing are somewhat different.
 

Redrig

Master Chief Petty Officer
Joined
Oct 13, 2009
Messages
849
Re: OMC electric shift convert to mechanical shift

Thank you for the response Boomyal. Been out of town, so just getting to reading this.

the only reason I would try to keep my existing upper is that it is sealed up well and has a pretty much brand new ball gear on it, I like that idea versus an unknown upper, but I think you are right, I might as well just grab the entire outdrive if I can.

I think I am going to give this a shot assuming the guy doesnt want absurd prices for the parts
 

sam60

Captain
Joined
May 21, 2011
Messages
3,189
Re: OMC electric shift convert to mechanical shift

I switched my electric shift to the hydro-mechanical drive back in 1979 and never looked back. After all these years with many hours of heavy use, I just had the drive gone thru a few years back, for general principals. It was probably good that I did because the water pump shaft splines were getting pretty worn.

...and yes, you can keep your existing intermediate housing. Make sure you get the the shift cable, the shift converter box and the shift/throttle control with all it's cables. It might be a good time to change the ball gears as well. T'would be good to start out with a new matching pair. You will also have to enlarge the hole thru the intermediate housing to accommodate the larger diameter shift cable. Then seal it with a stout sealer. The later IM housings had a seal and a cable retaining clamp which yours will not have.

If I had it to do over again, today, I MIGHT hold out for the later full mechanical drive and all it's associated components. I do however like the hydro-mechanical unit because you do not have to fuss with the shift interrupt system.

Oh, and one thing I forgot. Beware that your intermediate shaft and coupler that bolts to the flywheel have the finer splines. You do not have to remove them to do the drive swap and off course you would have to pull the engine to get to the coupler. Mine, with hundreds of hours of pushing a 20 footer and pulling many a skier was pretty worn. I replaced them both with the latter, larger spline set up. I had my engine and IM housing out to do a floor and bilge rebuild.

This might also be a good time to disconnect your TruCourse steering drum from the intermediate housing, lift it high in the air and shoot a good lubricant down the double cable way while repeatedly turning your steering wheel back and forth, lock to lock. After 30 years this made a huge difference in the reduction of my steering effort.

Gear ratios do matter but I think you would be fine going from V8 to V8. It is my feeling that you should swap the whole drive. Not expert enough to know if you could just use the lower. I do know that the housing are somewhat different.

10,000 posts! Thanks for helping us all!:)
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: OMC electric shift convert to mechanical shift

10,000 posts! Thanks for helping us all!:)

Gee, mzahn, I didn't even notice that.

Hey Bondo! Ya listenin? I just did my 10,000th post helping someone with an super duper OMC Stringer. I guess it was only fitting, huh?:p
 

Metalwizard23

Seaman
Joined
Jun 30, 2018
Messages
50
Hello I know this is an old thread but it seems to be on topic..

Im changing from Hydro assist to MECHANICAL..

What is the shift interrupt module and how do I add it.... or do I need it???

thanks
 

Metalwizard23

Seaman
Joined
Jun 30, 2018
Messages
50
Let me add to this..

I found "shift converter box" with the switches.. (used.. on ebay)
I found a wiring diagram showing how its connected through the switches and coil
I found SEVERAL different "modules" if I go this route how do I know what module will work with my setup???

Mines a 250 HP (351w)

thanks so MUCH!
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Closed - Old thread and new members don't read our rules. But that's OK, a new thread can be started at any time.
 
Status
Not open for further replies.
Top