Need help with counter rotating lower unit

Uncle D

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Mar 27, 2007
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What are the odds of getting two used motors with counter rotating lowers? Both had R.H. props. Boy, was I surprized first time I put them in gear!
Anyway, both needed rebuilding so I overhauled a 81' 235, got a L.H. prop and away I go. I bought a new side mount shifter, thinking (and I was right) the old one is wore out. Both lowers jump in and out of gear applying throttle. (shift cable is adjusted properly)
So I tear down one of the units. The reverse gear and clutch dogs are both wore/rounded. This is where I'm at.
Now, the foward gear/clutch dogs don't look bad. Looking at the photos in the repair manual, I can't see any differences in any of the parts, but pull up on the shift rod, the clutch slides back onto the reverse gear. Push the rod, it slides onto the forward gear. Looking at the way the bearings and such are made, it doesn't look like it is suppost to run on that reverse gear all the time. Am I wrong on this?
Now the other questions-
1. Can the thing be made so that it will shift the correct way and run on the forward gear, which looks like it has the big bearing made for running that way all the time.
2. If the only thing I can do is replace the reverse gear and clutch, will it hold up or am I going to have the same thing happen again. I ask this because with what I see, it just doesn't look like it should on that reverse gear all the time.

Any advice from the pros would be much appriciated. Thanks, Don.
 

Dhadley

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Re: Need help with counter rotating lower unit

Lets slow down a minute. Something don't seem right. First off, there was no c/r gearcase in 1981. Newer ones will work but it's not likely someone did that.

C/R gearcases have a little "c" or "cr" stamped right on the end of the propshaft. Look real close, kinda hard to see sometimes. If that ain't there, it ain't a backwards case.

The propshafts pull out differently. If you used a puller to pull the propshaft bearing housing - it ain't a backwards case.

If the propshaft bearing carrier was held in with 4 small bolts, it ain't a backwards case.

The forward gear in a C/R gearcase will be the gear to the rear (prop side) of the case and in the bearing housing. If the bearing carrier came out and both gears are on the propshaft, it ain't a backwards case.

You could have 2 Second Effort counter gearcases but let's hope not. What a mess that would be! And extremely rare!

It's possible you have 2 standard cases and the shift cables are hooked up backwards on the control. If you reverse the cable throw and run left hand props on std cases, it will try to run forward on the reverse gear. Probably will act just like you describe.
 

Uncle D

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Re: Need help with counter rotating lower unit

OK! I'm not nuts. Yes, the lower unit came apart just as you decribed! I didn't think it looked as if it should run counterclockwise.
So something is hooked up wrong. I have a brand new OMC side mount shifter. Even my old side mount works the same as this one.
Now the question is how to make the shift cable or linkage work as it should. Does OMC make a side mount shifter that is reversable? Becouse the throttle and shift cable are correctly hooked up to the shifter.
Could it be the linkage on the engine?
I'm going to double check the shift rod movement also.(down for reverse, up for forward)
Any thing else you can think of?

Thanks a bunch for your input, dhadley.Youv'e helped answer alot of questions. Don
 

Dhadley

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Re: Need help with counter rotating lower unit

Well, glad it was that simple (as far as the units go).

Now for the bigger question. Most of the OMC controls would only hook up one way. Not like a Morse or T-flex or even a Hynautic helm.

Any way you could post a pic? Or send one? When you push forward on the control handle it should go into forward gear. But yours is going into reverse. Which with the left hand prop will make the boat try to go forward.

A pic of the cable side of the control and the props would help.

Now -- what'da ya gonna do with 2 backwards props?
 

Dhadley

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Re: Need help with counter rotating lower unit

There wasn't anything funny about the gearcases -- like a wierd water pump with a metal housing rather than a plastic one?

When it did run was there anything funny about the water pressure?
 

Uncle D

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Re: Need help with counter rotating lower unit

Nothing weird with any of that. I'll get the pics soon.If I can't I'll give a detailed discription of what is going on. The cables are teleflex.
 

Uncle D

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Re: Need help with counter rotating lower unit

Did a double check. On the lower unit- push the shift rod down, prop shaft turns clockwise. Pull up, turns counter.
On the shifter- forward, cable shortens, linkage is pulled to front of engine, bell crank is pulled up. Reverse, cable lenghtens, bell crank is pushed down.
I'm stumped.
 

Dhadley

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Re: Need help with counter rotating lower unit

So with the gearcase off, you push the shift rod down. Then turn the driveshaft clockwise - right?

And the propshaft turns clockwise? Not turning the propshaft by hand, just the driveshaft.
 

Dhadley

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Re: Need help with counter rotating lower unit

What does the top of the shift rod look like?
 

Uncle D

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Re: Need help with counter rotating lower unit

thats right, push the shift rod down,cluch dog slides forward on prop shaft, into the forward gear. Then turn the driveshaft clockwise, the prop shaft also turns clockwise.
This is where I loose it. I thought on these OMC's that pushing the shift rod down puts the lower unit in reverse.
Put the shifter in forward this in turn pulls the bell crank up, the shift rod is also pulled up actually putting the thing in the reverse gear.
 

Uncle D

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Re: Need help with counter rotating lower unit

The shift rod is 1/4" round rod, as tall as the drive shaft. At the top of the rod its bent forward to the front of the engine. At the bend the sides are flatened.The top of the bend has the hole that the bolt goes through into the bell crank.
 

Dhadley

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Re: Need help with counter rotating lower unit

Hummm... I'm getting a sinking feeling now. You're describing how a Second Effort counter rotating gearcase works. But with a SE gearcase the motor actually runs backwards.

But, with either a standard case or a SE case if you push the shift rod down the dog should slide back toward the prop and engage the gear nearest the prop.

Have you got the gearcase apart now?

A really dumb question but just to be sure -- when you say the prop rotates clockwise, you are refering to standing behind the prop (& boat) looking forward, right? Not looking at the prop as if you were in front of the gearcase.
 

Uncle D

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Re: Need help with counter rotating lower unit

I have two gear cases, one apart the other I pulled the bearing housing out.
The one apart, I took the prop shaft with the clutch dog still on, along with the assist cylinder shift (the bottom section of shift rod inside the gearcase). I laid them out on a bench, flat side of the part, that is part of the clutch dog facing up (only way it can be assembled in accordance with the manual, I actually tried it the other way in the gearcase and it deffinatly won't work that way). When pushing down, it slides the dog forward.
As far as rotations, the motor turns clockwise, the drive shaft turning clockwise also, pull up on the shift rod,the dog slides back on the reverse gear turnig the prop shaft counter clockwise. Push the shift rod down the dog slides forward on the forward gear, turning the prop shaft clockwise.

Looking back on all this, this engine is set up to run clockwise/standard. It seems to me the gearcase is set up to shift in the opposite way of standard gearcases.
Pushing down on the shift rod positively slides the dog onto the forward gear. Don.
 

Uncle D

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Re: Need help with counter rotating lower unit

OK, armed with all the info. youv'e generously given Mr. Hadley, I talked to a local "old hand" who told me they did make lowers that were "different". He asked what shifter I had. "Brand new side mount" I said. He told me to go to a binnacle mount. Some of these mounts allow the cables to be reversed and have tilt/trim controls also.

Does this info. bring all this together? Hope all this is starting to make sense. Don
 

Dhadley

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Re: Need help with counter rotating lower unit

The gearcase that you have apart now -- has it ever been on the mid section? IE - have you ever tried to use it? Does it bolt up to the mid section?
 

Dhadley

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Re: Need help with counter rotating lower unit

Wait, wait, wait! What assist cylinder? That's from an older motor. The shift linkage is different and yes, it shifts opposite. But the shift rod you describe won't fit in that unit. Not without cutting and changing the top so it hooks up to the 1981 shift linkage.

The shift rod for a 1981 V6 screws into the lower after it's assembled. The earlier shift rod has to be put in as the prop shaft assemnly goes in.
 

Uncle D

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Re: Need help with counter rotating lower unit

Then I have an older gearcases. The case has two componits, shift assist that goes down to the dog. Then the shift rod that links up with the shift assist. Ofcourse the bell crank connects to the top of the shift rod.
This lower that I have apart, was on the motor and yes someone modified the upper part of the shift rod(cut and rewelded) Never have seen a # on any gearcase to help with date of manufacture. It's like on these two that I have, identical exept on the water pump impellers. One uses a half moon key, the other a plastic disk type key.
Anyway I found that Teleflex has a shifter that will work for this thing.
 

Dhadley

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Re: Need help with counter rotating lower unit

Ok, it's an old unit that has the shift rod modified. How does the shift rod adjust to get the correct height?
 

Uncle D

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Re: Need help with counter rotating lower unit

Also I did run this unit after the overhaul, I was on the breakin run and didn't go over 2500rpm or so. It still had the R.H. prop with the new side mount shifted. At that time I put the shifter in reverse to go forward, not knowing then that the lower shifted opposite.(I know now I was in the forward gear!) This is why I thought I had a counter-rotater and went to a L.H. prop. Of course this led from one problem to another.

I'm thinking this motor was on a boat with after market shifter.

See if you agree with this, I'll reassemble the lower,(new seals and such) install new teleflex shifter, R.H. prop, then fire this puppy up.(I will just pull the plugs and turn the fly wheel by hand with the lower in gear) Don.
 

Uncle D

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Re: Need help with counter rotating lower unit

They welled a threaded collar on the lower side of rod then cut treads on upper half of rod and then used a jam nut so it could be fine tuned.
 
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