1977 omc electric shift rebuild or replace?

[Cfinifrock]

Hi I'm new!
I have a 1977 Silverline Nantucket 302 190hp with omc stringer outdrive electric shift. I had the water impeller replaced,all new seals upper and lower,new transom boot, ignition switch and coil,new spark plugs,thermostat, and new battery so far! So I now have way too much in it to sell it.
Took the boat out twice since seal job...boat falls out of gear,won't go in,get towed in,get home and remove lower unit plug and straight water drains out. Smells hot. Cooked.
Take it back to shop who did work, he can't get any vacuum pressure,so he removed the unit. I walk in the shop about then, and together we find the drive shaft is broken and pinion gear damaged.
At this point I've done enough research to know I can use TC marine, or boatparts.ca in Canada,ship my unit for repairs,or buy a rebuilt unit and bolt it on. My thought is go with a new Lower unit,bolt it on for $1500 and hope it works. But, the question of why did it fill with water,and why did the shaft break remain. Don't want to throw money at it and not fix the problem. I also need to replace ball gears including intermediate. I don't have a press or bearing tools etc. So cost effectively speaking ,best bang for my buck,( which I don't have) what should I do?
But lower unit,and ball gear set and pay this guy to put them on and hope my upper is ok? I kinda lost faith in this dude. And I can't prove that the shaft got hot and broke because his seal job failed. He said he will help me put the unit back together if I buy the new Lower. But...also is TC the best way to go? I watch eBay but it's slim pickings on questionable parts.
Help please! Thanks

 

[kenny nunez]

I was an OMC dealer for many years and you are between the proverbial "Rock & the Hard spot.
The seal job may have failed due to the seal surface on the upper pinion shaft was worn and scored or the swivel bearing had a hole eroded through it . If the prop shaft seals failed there would have no water in the gearcase and no oil. If you go with the $1,500.00 unit and it is pressure and vacuum tested that may be your only option. It will probably come with a new shift wire. If it is not filled with oil the re check the tests before filling it. Use silicone grease to seal the wire through the exhaust housing and intermediate housing. The ball gear on the drive side always had a sealing problem when vacuum testing after some use. There will be small pits in the front seal running surface. When going from plane to idle the drive goes from positive pressure to vacuum and it sucks water through the inner seal. This problem developed when OMC started with the low profile drives which were 4" shorter than the older models. If your ball gears are wearing slowly and there is more than 50% left you may get by for the rest of the season. If they are wearing fast then it is time to throw in the towel and replace the whole engine and drive system as the upper gear case and intermediate are distorted and have to be replaced.

 

[Cfinifrock]

I think my ball gears are worn because they were engaged while till was up alot. The trim wasn't working when I got it,so I think the previous owner was using tilt too much. I smacked the trim motor with a hammer a few times and it has worked ever since.Everything seems good with the intermediate otherwise. I am considering buying the intermediate ball gear bearing shaft already assembled off eBay and just swapping them out shaft and all. Hoping they seal up good and work,no need for a press and all that. What do you think?
Sounds like buying a new Lower unit is the way to go there.

 

[Redrig]

Keep in mind that you can "upgrade" to a new newer versions of the stringer.

That is my plan .. I am electric shift right now and like you I have a Ford 302 . That at least gives us the option of moving up to a hydro mechanical or full mechanical outdrive , yes there will be some changes that you have to make but if you can find the right unit it will make more sense than dumping money into the electric shift .

Luckily , my current electric lower unit has been fairly reliable . I broke a shift spring in my original lower unit and I have that fixed and ready to go as a backup . But I am not buying anymore parts for the electric .

I am always on the look out for a mechanical shift from a V8 with a bad engine , then I can just swap everything over.

Good luck !

 

[kenny nunez]

Before ordering the shaft assembly remove yours and measure the length. There was 2 different lengths. If those ball gears get to the point where they "slip" over one another it is really bad news. Then as I said before it is throw in the towel time.

 

[Cfinifrock]

I read that the hydro shift was not much better, but I am curious about going to mechanical. I assume that it's just the same as electric except it uses cables instead of switches. Seems like the internal parts would still be the same. Minus the magnets??? IDK. Is TC Marine the best option for buying a refurbished lower unit? Can I trust them? I think I'm going to pay for the core and keep my old lower and either part it out or keep for spare parts. They only give you $260. I can make more than that parting it out I think. I appreciate the advise from everyone. It seems like I have become a part of the old and ancient boat owners community. I had no idea what I was getting into. "If it runs and floats I'll buy it" got me in this mess. Plan is to fix the lower unit and ball gear, sand and refinish the wood, floor and carpet, and put for sale on it! Love having a boat, and love this boat. BUT it's always going to cost me too much money to keep this one alive. Meanwhile while nobody wants to buy it...we will use it! Anybody need lower unit parts?

 

[kenny nunez]

To convert to a mechanical system requires a different intermediate housing . You would be better off staying with the electric lower.

 

[Redrig]

To convert to a mechanical system requires a different intermediate housing . You would be better off staying with the electric lower.

I dont think so . There is a fella on here Boomyall that did the conversion a long time ago and all he did was drill the hole for the shift cable a tad bit larger (for the fatter shift cable) and that was basically it , the upper fits right into the older style intermediate .

you then just add the the controller, shift converter , ect .

and sorry - I am not trying to derail this thread about a conversion . Just wanted to point out that a conversion could potentially be an option if the opportunity presented itself .

 

[kenny nunez]

Since there is enough material on the intermediate for the mechanical cable there also may enough to use the original upper gear housing. Then all that will be needed is the top cover and the 800 series exhaust housing to mate them together.

 

[Boomyal]

To convert to a mechanical system requires a different intermediate housing . You would be better off staying with the electric lower.

Sorry Kenny, not true. I have a '75 302 that came with the electric shift outdrive. Three years out it kept breaking the forward clutch slinky and no one could figure out why. At that point (1978/79) I had a dealer change the unit out to the then current hydro-mechanical unit. I still have it today. It has gone thru one rebuild after hundreds of hours of heavy water skiing use. They had to change the shift unit, add the converter and enlarge the hole thru the intermediate housing to accommodate the mechanical shift cable. I still have the original intermediate housing with the later, larger splined drive shaft and flywheel coupler that was replaced during the 2006 tune up. I am still using the original ball gears.

At the time everyone said it couldn't be done. I am going on 40 years now that says IT WORKS!

 

[Redrig]

I am still using the original ball gears.

Original ball gears from the 70's ?

 

[Boomyal]

Original ball gears from the 70's ?

Yep, from 1975 and 1979. The original 1975 intermediate shaft ball gear showed no appreciable wear at the time the conversion to the hydro-mechanical was done. The new outdrive unit had it's new ball gear so the dealer just let them mate up. They are both still on the assy as I type. I was always careful not to run the outdrive up except for a few seconds to get out of trouble.