1986 OMC 800 shift problem...need help

Brijoe00

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I have a 1986 Seaswirl with a OMC 800 outdrive. I am having trouble getting it into reverse. I have concluded that the upper cable that go's to the remote is fine. I tryed adjusting it as per the manual instructions and it didnt help. I am finding that when I detach the shift cable from the shift arm on the converter and push the arm forward it engages dissengages from forward no problem. When I push the arm to reverse all the way it sometimes will engage and sometimes not.

Is there something else I should look at and test? Could it be the lower cable that go's to the lower unit? If so how do I check that. Any help would be appreciated.

Thanks in advance
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

anyone have any advice?
 

wire2

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Re: 1986 OMC 800 shift problem...need help

I'd take the cover off the shift converter and have a look in there. There's a ?" bolt through the square pivot and 4 slotted screws in the cover. The shorter aircraft cable should go to the left corner of the pie shaped wedge, the longer one goes around the idler pulley in the left corner, then to the right edge of the wedge. The 2 cables must not cross each other and be under slight tension.
Place a wrench on the square pivot and lever it through neutral into fwd & rev. It should go in/out with little effort, maybe 15-20 in. oz. each way. Yes/No?
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

Ok. I popped the cover off the converter. The aircraft wires are not crossed and are secured into the correct places. When I turn the pivot with a wrench it go's into forward with little effort. When I go to reverse I turn it all the way over and it does not engage. I can see when the pivot is all the way over to reverse the wire slacks up at the top of the wedge a tiny bit, probably just due to the cable is extended all the way.
 

wire2

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Re: 1986 OMC 800 shift problem...need help

I hate to suggest it but it sounds like a problem in the lower outdrive.
Although just before you commit to pulling it all apart, here's 1 last check; put a screwdriver between the ratchet pawls near the cable, push the cable in to get some slack, and undo the ends from the pie wedge and remove the cable from the converter. Pull the short cable all the way out to engage fwd, then the longer one to go through neutral into rev. Does it go in to gear clean & fully? If no, then bring your toolbox to the back of the boat.
Don't forget the ?" bolt holding the ss clip on the cable on the outside of the mid-drive.
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

Alright. I undid the cables and pulled the cable to forward, it engaged, pulled through nuetral and into reverse, did not engage. I pulled through to reverse untill it would not pull anymore, I could hear a faint grinding in the drive like it was almost engaged, but the cable would not pull anymore. Any ideas what it could be in the drive?

This is where it intimidates me. I am fairly mechanical, but I have never taken an outdrive apart before. Do I just take the lower unit off? and what am I looking for? I am considering takeing it in, but I would like to know if I could do it.
 

wire2

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Re: 1986 OMC 800 shift problem...need help

It's always intimidating if you've never had one apart before. There's a few tricks. Got a proper manual? I'll help you through it, just PM me.
 

KaGee

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Re: 1986 OMC 800 shift problem...need help

Remove the lower oil drain and inspect for shavings.
You could possibly have a bad clutch dog.

Shifting over 700 RPM, Jumping immediately from forward to reverse, or stretch in the shift cable not properly adjusted for, can cause cause the dog to wear. Once it wears only a little, you are SOL. That requires a new dog and gears IF it's where the problem lies.
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

I just went out and drained a little bit of oil in a paper cup. I didnt see any shavings in there. I ran my fingure through it and didnt feel anything gritty either.
 

jmacek07

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Re: 1986 OMC 800 shift problem...need help

I have a 1986 SeaSwirl with the 3.0L OMC outdrive as well. Mine also will not shift into reverse. When trying to do this you hear it trying but it sounds like something just isn't catching. I called an OMC Mechanic in Spokane and apparently he's seen this before. He thinks it's some pin that has broken. He thought it'd be about $500 to fix.
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

Ugh...I dont want to spend that much on it, I just spent a bunch at the beginning of the season on seals and an impellor. The joys of owning a boat I guess.

Hey Jmacek, I am in Spokane as well!! Nice to see someone local on here.
 

jmacek07

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Re: 1986 OMC 800 shift problem...need help

I know what you're talking about. I bought this boat from a guy this spring who said it was in perfect working condition. Apparently he didn't feel that not being able to reverse was note worthy. My bad for not test driving the boat before purchasing though. I also dont really want to spend that kind of money to fix it but I'm afraid I'll have to as if I ever want to sell the boat there isn't anyone who would want to buy it without reverse.

I'm actually in Cd'a but I have a good friend over in Spokane who directed me to this guy. It's kind of weird we both have the exact same boat it seems with the exact same problem?!?!
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

OK so I have kind of determined just by the advice on here and talking with a mechanic that the clutch dog and the reverse gear are bad. I have one other question though.

I notice that when I manualy push the shift interupter switches I notice no change in the engine. Should I be able to hear the engine sputter a bit when those switches are pushed? If these switches are bad will it cause the reverse to not engage?
 

jmacek07

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Re: 1986 OMC 800 shift problem...need help

I'd love to help but I'm far from a mechanic.
 

wire2

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Re: 1986 OMC 800 shift problem...need help

I'm not a mechanic either but I have done lots of maintenance on my own and other drives.

Pushing one of the limits won't affect a running engine if it's the neutral start switch.

If it's the shift assist switch, yes, the engine should stumble and lose rpm's. If not, the module may be defective. I had to replace mine.
 

jmacek07

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Re: 1986 OMC 800 shift problem...need help

OK so I have kind of determined just by the advice on here and talking with a mechanic that the clutch dog and the reverse gear are bad. I have one other question though.

I notice that when I manualy push the shift interupter switches I notice no change in the engine. Should I be able to hear the engine sputter a bit when those switches are pushed? If these switches are bad will it cause the reverse to not engage?

I hope this isn't the problem with mine because I've been looking online and the parts to fix that are spendy ;-( Wow!
 

Brijoe00

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Re: 1986 OMC 800 shift problem...need help

So would a bad module prevent the reverse from engageing, but still allow forward to engage? The switches I am talking about may not evan be the shift interupter switches I think they are. They are the microswitches locate on either side of the shift arm on the converter, are these the shift interupters? or the neutral start switches?
 

KaGee

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Re: 1986 OMC 800 shift problem...need help

Actually the shift module aids more in getting the drive out of gear.
 

Manipulator

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Re: 1986 OMC 800 shift problem...need help

To determine if it?s the cable I would completely remove it from the shift box, pull one end as far as it will go and see if it goes into forward, which it should, then pull the other end as far as it will go and see if reverse engages. If reverse does engage then your nominal neutral setting is probably out of whack. The cable is being pulled far enough to go into forward but not reverse. This can be easily adjusted if it is the case. Hopefully it is. As far as the switches go it does not affect the engagement of the gears as much as it does coming out of gear. The micro switches turn the interrupter off, so pushing them won?t stumble the motor. The third switch attached to the arm with the little cam is the switch that turns the ESA on. You can turn the motor on, push the third switch plunger and she should go into stumble mode, then you can push one of the micro switch plungers and it should shut off. One micro switch is for shutting off the ESA once you are in forward gear and the other is there for once you are in reverse.

Now let?s turn our attention to the dog clutch if you find the cable is working fine. The dog clutch is a stout, hollow, sliding cylinder splined to the propeller shaft, with teeth cut into each face for engaging the adjacent gears (forward and reverse). The teeth on the clutch dog resemble the top of the "rook" piece or the castle in chess. Each side of the dog clutch has this appearance. Immediately adjacent to the clutch dog on the propeller shaft are gears that spin freely on the shaft. These gears mate with a third gear that is driven by the engine, thus these gears are always turning while the engine is running. These gears turn in opposite directions. The stern drive is in neutral when the clutch dog is between the nearby gears; the drive engages forward or reverses by sliding the clutch dog into the appropriate gear that turns with the engine. This is done via a shift rod that is operated by the shift cable.

There is no "clutch," as you find in an automobile. Gears engage with a jolt. The shift interrupter kills a few cylinders in the motor to lower the RPM and torque to allow this jolt to be as less of a jolt as is possible and allow to the clutch to engage more smoothly.

My guess is that the reverse side of the dog clutch, the castle top shaped notches has broken. They are fine on the forward side since you can go into forward. Going into reverse you wouldn?t hear the momentary grind as the clutch attempts to engage into the reverse gear. It?s possible it?s the reverse gear itself (notches stripped) but I?m leaning towards the clutch being broke.
 
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