1972 50HP Electric hydraulic Shift problem

[ARayT]

Have an old 50hp OMC 1972 w/ electric shift that Im having problems with. I took it out for the first time this year it did not want to shift into forward gear. It was jerking in and out real roughly I finally got it to stayed in forward gear. It would shift into reverse and neutral w/ no problem. I used it for the rest of the day just leaving it in forward and had no problem. I've searched this problem and somewhat understand how it should work w/ the fail safe in forward the 2 soleniods and such but not sure what to check with this. I have never had this problem before any help would be appreciated. Thanks Ray

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

Have an old 50hp OMC 1972 w/ electric shift that Im having problems with. I took it out for the first time this year it did not want to shift into forward gear. It was jerking in and out real roughly I finally got it to stayed in forward gear. It would shift into reverse and neutral w/ no problem. I used it for the rest of the day just leaving it in forward and had no problem. I've searched this problem and somewhat understand how it should work w/ the fail safe in forward the 2 soleniods and such but not sure what to check with this. I have never had this problem before any help would be appreciated. Thanks Ray

First thing you want to check is the voltages at the blue and green wires back at the powerhead. Slide the insulator sleeves back, but leave the wires connected. You should see battery voltage at the green wire when in neutral, and battery voltage on both green and blue wires in reverse. No voltage on either wire in forward gear. Check it a whole bunch of shift cycles. Bad shift switches in the remote control are notorious.

 

[Barnacle_Bill]

Re: 1972 50HP Electric hydraulic Shift problem

Drain the oil from the L/U and refil with type "C" or premium oil. If the oil is milky looking you have some bad seals. On second thought it wouldn't hurt to do this but it should go into fwd even with no oil in it.

 

[jay_merrill]

Re: 1972 50HP Electric hydraulic Shift problem

Could be electrical and I agree that this is where I would start in the troubleshooting process, but the "jerking in and out of gear" thing makes me wonder if you just have a bad clutch dog. That's pretty much what any of them (hydroelectric system or not) do when they start to go.



???

 

[rodbolt]

Re: 1972 50HP Electric hydraulic Shift problem

for fwd NO voltage is applied to Either solinoid.
the shift clutch piston is spring loaded to default to fwd gear anytime there is a lack of hydraulic pressure on the piston.
time to take it in,have it dissasembled,cleaned and tested BEFORE something tears up.
a lot of the internal parts for the hydro electric are rapidly becoming NLA.

 

[ARayT]

Re: 1972 50HP Electric hydraulic Shift problem

I forgot to mention that the only way I could get it to go into forward gear was to reeve it up.

I did drain the fluid (type C) out and it did have a milky color to it. I was hoping I would not have to tear into the foot but with this I may have to.

By checking the wiring are you thinking I may have a short and this is keeping the neutral solenoid energized? I?ll check this and see.

It?s in forward gear not running, I tried turning the prop last night and I was rotating the engine.

Thanks for the advice, I?ll let you know how it turns out.
Ray

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

I forgot to mention that the only way I could get it to go into forward gear was to reeve it up.

I did drain the fluid (type C) out and it did have a milky color to it. I was hoping I would not have to tear into the foot but with this I may have to.

By checking the wiring are you thinking I may have a short and this is keeping the neutral solenoid energized? I?ll check this and see.

It?s in forward gear not running, I tried turning the prop last night and I was rotating the engine.

Thanks for the advice, I?ll let you know how it turns out.
Ray

It takes electrical AND hydraulic power to get it OUT of gear. That is why you need to check the voltages. There should be no power on either wire when in forward. If there is, you have a defective shift switch or shorted wiring. Doesn't it make sense to make such a simple test before ripping into the lower unit?

If it passes the electrical test, the next suspect would be rusted solenoids from that water in there. If the solenoid plunger doesn't move freely, it will hold the hydraulic valves closed.

The clutch dog and piston are probably sliding freely since it goes into forward when not running--as it should. There is no hydraulic pressure when not running, and it makes no difference then whether the electrical part is good or not--it should slide into forward.

 

[ARayT]

Re: 1972 50HP Electric hydraulic Shift problem

Thanks for the advice!! I checked the electrical no voltage on either wire while in forward, I disconnected both wires still no forward. It again went into reverse and neutral with no problem. I set and let it run for several minutes and it finally went into forward. Switched back and forth several times and each time it took around 1 to 1-1/2 minutes for it to shift into forward. So I pulled the foot and removed the solenoids. It all looked OK, no rust, gunk or anything and everything looked like it would move freely. Would it be something internally? If so can I still get parts?
Thanks Ray

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

Thanks for the advice!! I checked the electrical no voltage on either wire while in forward, I disconnected both wires still no forward. It again went into reverse and neutral with no problem. I set and let it run for several minutes and it finally went into forward. Switched back and forth several times and each time it took around 1 to 1-1/2 minutes for it to shift into forward. So I pulled the foot and removed the solenoids. It all looked OK, no rust, gunk or anything and everything looked like it would move freely. Would it be something internally? If so can I still get parts?
Thanks Ray

If it isn't electrical and the solenoids are ok and adjusted properly, then it must be a problem with the piston sticking in the oil pump. Kind of unusual that it unsticks eventually though. Can't tell you the exact nature of the problem without tear-down and inspection.

Just for the record, when the solenoids are energized, they press down on a couple of levers that in turn hold a couple of balls against their seats. That obstructs the flow of oil through the ball valves and the resuliting pressure moves the piston, which moves the clutch dog.

When the solenoid is de-energized, oil pressure pushes the ball up off the seat, which raises the lever, which pushes the solenoid plunger upward. Result is oil again flows through the ball valve, and no pressure is applied to the piston, and a spring pushes the clutch dog forward into neutral or forward, whichever applies.

Oil viscosity matters, but you said you already addressed that issue.

 

[ARayT]

Re: 1972 50HP Electric hydraulic Shift problem

FR Thanks for the explanation. I had some idea but its clearer now on how it works. Do you know if I can still get parts? I'll tear it down tonight. Hopefully I'll be able to figure it out. I just reworked the carbs and got it running real smooth, I hope I didnot do all that for nothing. Many many thanks for the help!
Ray

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

FR Thanks for the explanation. I had some idea but its clearer now on how it works. Do you know if I can still get parts? I'll tear it down tonight. Hopefully I'll be able to figure it out. I just reworked the carbs and got it running real smooth, I hope I didnot do all that for nothing. Many many thanks for the help!
Ray

Almost all parts are available

 

[papasage]

Re: 1972 50HP Electric hydraulic Shift problem

could the screen on the pump be cloged?seams like i read that some where in a book i have .the book is a 1972 evinrude shop manual .

 

[rodbolt]

Re: 1972 50HP Electric hydraulic Shift problem

a no fwd shift is not an electrical issue,either the shift clucth is sticking the shift piston is sticking or the pump check balls are gummed up or damaged,the solinoid rods may be sticking or the shift piston oring,which does not come in the seal kit,is swollen and binding. even with NO oil it defaults to fwd gear, anytime the engine is off it defaults to fwd gear.
its spring loaded to default to fwd gear in an event of hydrualic or oil pressure failure.
last time I needed a fwd gear and a pump neither were avalible from BRP.
thats why it needs to be fixed before its damaged.
dont break the shift wires either,last I bought were over 100 dollars back in the mid 90s and some are NLA.
I dont see many here in the saltpond anymore but for years I speacilized in hydro electric cases.

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

a no fwd shift is not an electrical issue,either the shift clucth is sticking the shift piston is sticking or the pump check balls are gummed up or damaged,the solinoid rods may be sticking or the shift piston oring,which does not come in the seal kit,is swollen and binding. even with NO oil it defaults to fwd gear, anytime the engine is off it defaults to fwd gear.
its spring loaded to default to fwd gear in an event of hydrualic or oil pressure failure.
last time I needed a fwd gear and a pump neither were avalible from BRP.
thats why it needs to be fixed before its damaged.
dont break the shift wires either,last I bought were over 100 dollars back in the mid 90s and some are NLA.
I dont see many here in the saltpond anymore but for years I speacilized in hydro electric cases.

rodbolt, I'll wager a bet that you have seen Johnson shift switches that the arm fell off of. Or Evinrude push button switches that were just plain inoperable.

Nevermind that, the gear is part number 383978, $125. The oil pump is 385057, $300. Direct from BRP website. All it takes is money.

 

[jay_merrill]

Re: 1972 50HP Electric hydraulic Shift problem

To me, his problem does not sound electrical and he has done a few things to confirm that. Even so, I think I would have run a couple of electrical checks anyway. Why? Because you have to start some place and even though electrical problems usually result in not being able to shift into neutral and/or reverse, I don't think that it would be impossible to have a condition where voltage is being applied to the upper solenoid, when it wasn't supposed to be. If that's what you were getting at with the broken parts scenario, F_R, I can see your point.

At the risk of sounding wishy-washy and like I'm trying to please both of you, the likelyhood of such a scenario is probably remote. Once again, however, troubleshooting is a process of elimination and eliminating electrical as a possibility is easy and quick. It also makes sense, because going right to a teardown of the gearcase could end up making the mechanic frustrated, if there wasn't anything wrong with the internals.

In the end, as long as you find the problem and can fix it - its all good.



???

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

At the risk of sounding wishy-washy and like I'm trying to please both of you, the likelyhood of such a scenario is probably remote. Once again, however, troubleshooting is a process of elimination and eliminating electrical as a possibility is easy and quick. It also makes sense, because going right to a teardown of the gearcase could end up making the mechanic frustrated, if there wasn't anything wrong with the internals.

In the end, as long as you find the problem and can fix it - its all good

???

Hey, no need to please me. I simply give my advice and the person is free to take it or not take it. I'm not fighting or arguing with anybody. It simply isn't worth it, especially at the rates that I charge. Guaranteed 100% full refund of all money paid if I'm wrong.

In this thread, I said right up front that the first thing to check was the electrical, than if that isn't the problem move on to more serious issues. Jay, as you suggest, it just makes sense.

This guy apparently is well on his way into the gearcase. Wonder how he is doing? Think it will ever live again?

 

[rodbolt]

Re: 1972 50HP Electric hydraulic Shift problem

have I ever seen the arm fall off,yep, pushbutton switchs fail, yep. have a ever dissasembed,cleaned and reassembled push button switchs? yep.do I wanna anymore? nope.

have I ever seen clippers fail? yep.
but his description fits none of the above.
back in the late 80,s I bought about 50 hydro electric units from a boat junk yard for 800 dollars.
some were mostly junk others easily repaired.
for the next 10 years I would sell,with a 1 year warrenty, V4,3cyl and 2 cyl lower units for 350 dollars and the old unit exchange or 450 outright.
was decent money untill they mostly dissapeared here.
salt water killed the powerheads.
about 5 years ago I needed a pump and fwd gear,for a friend, for a 72 50 and the dealer said it was NLA. maybe its back in production.
the dealer has been an OMC/BRP dealer since about 1954 ands I worked for him a few years.
but the description simply does not follow a bad vacum hold switch,not used on the 72 50, nor a bad hold diode assy.
it does decribe a stuck shift piston or a faulty oil pump check ball.
but continued running with the unit popping in and out will lead to clutch/fwd gear damage.
with any luck I will never work on one again .

 

[ARayT]

Re: 1972 50HP Electric hydraulic Shift problem

F_R your right I tore it down tonight. The only thing I found was the shift piston was real hard to move, but it was in forward gear position when I removed it (if all the way back into the oil pump is forward position). I had to take a pair of pliers and really twist it hard to get it to move. Are they supposed to be that hard to move? But did it not have to be moving though to shift into neu and rev? The screen was clean. When this happened it did not sound like it was in gear and was just slipping. The clutch dog and gear do show some wear but I ran it all day in forward and it never slipped. Its got me scratching my head, I?m at a lost. Any advise?
Thanks Ray

Boy you gotta have patients to work on these things!!

 

[F_R]

Re: 1972 50HP Electric hydraulic Shift problem

F_R your right I tore it down tonight. The only thing I found was the shift piston was real hard to move, but it was in forward gear position when I removed it (if all the way back into the oil pump is forward position). I had to take a pair of pliers and really twist it hard to get it to move. Are they supposed to be that hard to move? But did it not have to be moving though to shift into neu and rev? The screen was clean. When this happened it did not sound like it was in gear and was just slipping. The clutch dog and gear do show some wear but I ran it all day in forward and it never slipped. Its got me scratching my head, I?m at a lost. Any advise?
Thanks Ray

Boy you gotta have patients to work on these things!!

First, congratulations on getting it apart. You are smarter than the average bear. The piston should be a very close slip fit in the bore. What usually makes them tight and sticky is fine grit imbedded in the aluminum bore. Grit so tiny that it passes through the screen. You can polish the bore a bit, but don't make it oversize or there will be excessive leakage past it.

 

[ARayT]

Re: 1972 50HP Electric hydraulic Shift problem

First, congratulations on getting it apart. You are smarter than the average bear. The piston should be a very close slip fit in the bore. What usually makes them tight and sticky is fine grit imbedded in the aluminum bore. Grit so tiny that it passes through the screen. You can polish the bore a bit, but don't make it oversize or there will be excessive leakage past it.

I really appreciate you guys help. It being that tight do you think this was the problem?? How much wear would you allow before replacing the clutch dog and gear?