OMC Stringer electric shift 1971 no forward gear shifting!

[fazerpaul1970]

Hello from Holland,

Being new to this forum I first of all wanna say thanks for making this a great place for helping boat owners solving their problems!

Okay, here's my problem.. ;-)
I recently bought a vintage Tullio Abbate speedboat with an OMC V8 235 HP engine and a Stringer electric shift outdrive. On the engine there's a tag saying the engine was built in 1971. When I toke the boat to the lake for the first time shifting was good and smooth. On my way back to the harbour speeding around 3500 rpm, suddenly the drive lost forward gear and the engine revved up fast. I pulled back the lever and shifted into neutral, then tried several times to shift into forward gear but the clutch didn't lock anymore. So I had to drive the boat back in reverse gear, which made me the hero of the day at the marina, lol!

Today, a friend and I tried to figure out what went wrong with the shifting. We checked the leads going from the shifter lever to one of both large connectors on top of the engine behind the carb. I disconnected the leads at this point and we measured voltage for forward and reverse coils while moving the lever. Both leads gave us a solid 13,3 Volts with fully charged battery. Then we measured the Amps going through the same leads and we got 2,12 Amps for both coils, is that okay?

When shifting into reverse you can hear a solid click in the lower unit, while shifting into forward there only is a faint click. I tried to spin the prop and it nicely locked in reverse but in forward it spins with a rattling sound or sometimes it lockes but under load falls back to neutral.

We also checked the lower unit oil and it was totally black and free of any metal chips. I know of the dark green colour of Mercruiser gear lube but how about this black lube, is this the type C lube?

So.. any ideas of what happened to my vintage oudrive?Any help is greatly appreciated!!

Thanks,
Paul

 

[southkogs]

Welcome aboard Paul:

Type C shouldn't be black. Have you tested the forward coil for resistance? Connect to the shift wire going into the leg and see how many ohms resistance you get. Should be between 4.5 & 6.5 ohms.

 

[fazerpaul1970]

Thanks Southkogs for your quick reply!

I just measured the resistance of the coils. They both give readings around 5.8 Ohms.

Can you please tell me more about the gear lube that should be used in this drive? What colour is normal and how many cc's should be inside the lower unit?
We measured the volume of the black oil that came out yesterday and this was around 550 cc's (0.58 quarts). Is that the proper volume of lube?

I forgot to mention that before the drive lost forward gear at nearly wot, it disengaged once and came back in gear while moving the shifter so the engine rpm lowered.

Thanks a lot for your help!!

Paul

 

[southkogs]

33.9 OZ / 1000 CCs is what the lower unit should hold. To be honest, I can't tell you what color the stuff should be without going out an opening a bottle of it It won't be clear, but translucent. Type C is the correct lube for the lower unit, and that can make a substantial difference.

 

[fazerpaul1970]

Okay, that means there was half the volume of lube in the foot and likely the wrong type of oil. So, I'm gonna get fresh type C lube asap and see if this makes any difference.. I really hope so!

 

[fazerpaul1970]

As soon as the lube is in the lower unit, I'll let you know the result!
Thanks!!

 

[southkogs]

It can make a substantial difference ... so well worth trying. Best wishes!

 

[fazerpaul1970]

Yesterday I ordered OMC Premium Blend gear oil, it should be right for all electric shift models. As soon as it gets here, I'll fill the drive and really hope it's gonna again. Fingers crossed! :angel:

 

[fazerpaul1970]

this one!

 

[southkogs]

I've not tried that one, but it says it'll work. I've been using THIS.

 

[VE8EV]

It sounds like the drive may have dropped out of gear due to an intermittent electrical connection somewhere in the shift circuit. If that happens, and it re-engages at high RPM, it will break the forward shift spring. If you later find that spring is broken make sure you examine all the wiring and the shift switch circuitry when you replace it or exactly the same thing would likely happen again.

John

 

[VE8EV]

Also, despite the tag you found (and the black paint), that engine and drive are a 1974-77 vintage. There should be a model number plate attached to the fuel filter bracket at the front of the port exhaust manifold if it hasn't been removed.

 

[fazerpaul1970]

Thanks guys for your great advise! John, I'm afraid what you described has happened and this likely broke the spring.
Today the fresh lube arrived at my door and I will fill the lower unit this weekend. I'm guessing now this isn't gonna fix the problem, no good.. :Cry:

 

[fazerpaul1970]

Okay, I just filled the lower unit with fresh lube. The shifting problem hasn't changed which I was expecting.. too bad!
When I shift into forward gear, the prop shaft sometimes locks turning the prop counterclockwise. Other times it just won't lock at all or snaps free when turning with some strength.

I assume there is a mechanical problem causing this malfunction, but don't understand what it is.. If the forward spring is broken, how can it sometimes lock the prop shaft and other times not? The electrical circuit seems to be working fine, we measured the leads and coils.

Any suggestions? Many thanks!!

 

[VE8EV]

Here's a pretty good overview of what's going on in there:
[url]http://www.sterndrive.info/electric_shift.html[/URL]
http://www.sterndrive.info/clutch_spring.html

 

[mtodd101]

FazerPaul

I've got the sort of the same problem with my 1976 electric shift. went out and lost forward gear. I'm just going to rebuild another lower unit and replace the broken lower unit. New shift cable also. Is that a little more economical? My drive is a 140 hp with 15.23 lower gears and the out drive I'm rebuilding (175HP) has the same lower gears. The only thing I'm not sure of is what the term "total" means in my Seloc manual in regards to gears ratios. The 140 hp has a total of.62 and the 175 hp has .72. Matt

 

[VE8EV]

I've got the sort of the same problem with my 1976 electric shift. went out and lost forward gear. I'm just going to rebuild another lower unit and replace the broken lower unit. New shift cable also. Is that a little more economical? My drive is a 140 hp with 15.23 lower gears and the out drive I'm rebuilding (175HP) has the same lower gears. The only thing I'm not sure of is what the term "total" means in my Seloc manual in regards to gears ratios. The 140 hp has a total of.62 and the 175 hp has .72. Matt

You should really start your own thread instead of tagging on to someone else's -but- the 72-77 lowers are all the same ratio. Only the uppers are different.

 

[fazerpaul1970]

Thanks VE8EV, this is really helpful information! I'm wondering if this can be done without special tools. I've got some tooling experience doing engine and outdrive maintenance, but this seems to be more difficult. Can you advise me on doing this job myself?

 

[VE8EV]

Fortunately, I have never had to get into my lower gearcase before but I do have all the text and pictures from sterndrive.info tucked away for future use just in case.

It looks like the only special tool required is a big pair of snap ring pliers. Also, I kind of gather from their web site that if the spring is broken right at the face of the clutch hub then it can sometimes be re-used. Since the forward and reverse springs are the same I might be tempted to swap them around if you can't get a replacement.

Given your location, you probably don't have much to lose by giving it a try. Probably not too many used drives for parts around there (I'm guessing) and, worst case, you ship the whole lower unit out to Canada to have it rebuilt. New springs (OMC 313455) are no longer available but TC Electronics sells used ones and they have seal kits. Note that if you're ordering parts, like I mentioned before, your drive is not a 1971 but newer, likely 1975/76, and the lower units are all the same from 72-77.

Let us know how you make out!

 

[southkogs]

Sent ya' a PM fazerpaul.