OMC Cobra Not Going Into Gear

[Isshinryuninja]

So this is my first time posting ,after looking through the forums for about a week. I just bought an old 1994 Four Winns Freedom 170, it has the 4.3L with the OMC Cobra stern-drive. I will post serial number once I get home from work.

Of the three times I took the boat out, an issue has occurred each time.(swimming boat back twice)

This time we just got on plane and then a low shuttering/ rumbling came from the back end. So I put the boat in neutral and came to a stop, then I tried to put it back in forward gear . The engine felt like it was going to stall, and as soon as I put it in neutral the engine idled fine. Did this a couple times, the engine revs up fine, but the propeller doesn't spin in forward or reverse. The boat doesnt even feel like it clicks into a gear, I feel its an out drive issue. The gear shift feels the same without any hard resistance.

Any simple ideas to check first? With the boat off, I am going to put it drive and see if the propeller spins. I am assuming it will.

All help, comments, critiques and funny jabs are welcome.

-Sean

 

[southkogs]

Welcome aboard:

Check the gear lube in your stern drive ... see if you see muddy looking oil, or metal pieces/shavings. Then my next suspect would have a look at your shift assist module.

 

[Isshinryuninja]

southkogs
Thank you for your reply and welcoming me, I changed the gear oil right when I bought it and Im glad I did. It had a milky consistency, which I assume was water. There weren't any gaskets on the oil drain/vent holes so I put them on.(They weren't stuck on the stern-shaft either.

I just Googled what the shift assist module was and that is a good possibility , I will look into this.

My first thoughts were shift cable or u-joints, but I havent experienced a bad u joint before, so I dont know how that would feel.

Thanks

 

[Isshinryuninja]

So here are some more details now that I am home.
OMC Cobra Outdrive
Model #987344
Serial #T00774293

I put the shifter into gear and the propeller spins, but has a noise. Best way to describe it sounds kinda like a baseball card in a bike wheel.

I am unsure where the shift assist model would be on my boat?

Thanks

 

[Lou C]

Post up a pic. If your power package is really a ‘94 then it’s the joint venture with Volvo drive and is the same as a cone clutch Volvo SX. However, a ‘94 boat could have a ‘93 Cobra package which was the last year of the dog clutch shifted Cobras (with ESA).

 

[Isshinryuninja]

Here is the stern drive. If I put the boat in forward pr reverse, the propeller spins both ways.

I looked in the engine compartment and the linkage seems to be working, its changing direction. Not 100% sure where it needs to be for functionality though.

 

[southkogs]

Whoah ... that outdrive lube drain was what you mentioned above, right? Any metal pieces in it?

 

[Isshinryuninja]

southkogs , Lou C
That gear oil is only a week old and the picture is what I drained last night. There was a very small amount of shavings on the oil drain screw.

Does it sound like I need to pull apart the out drive and check for bearings and u joints.

Thanks

 

[southkogs]

Some shavings on the drain plug is sorta' normal - don't wanna' see a lot of 'em, but they will be there sometimes. BUT that kind of water intrusion to the drive is suggesting to me that you've got a gear box that's on it's way to locking up - and that can cause the engine to bog/shut down.

So "yes" you need to see what's happening in the drive - gears, shafts, seals, etc. But I don't know the Cobras well enough to tell you how to get into the gear box, and I don't know the gear boxes well enough to tell you how to evaluate it. Maybe Lou C or kenny nunez has can give some direction.

 

[HT32BSX115]

I changed the gear oil right when I bought it

Howdy,

You clearly have a Dog-Clutch Cobra.

It's one of the below models
432APLJVB 1993
432APLJVN 1993
432APRJVB 1993
432APRJVN 1993
434APLJVB 1993
434APLJVN 1993
434APRJVB 1993
434APRJVN 1993

For most problems it's really helps if you post your model number

When you changed your gear oil, which opening did you pump the new oil into?

 

[Isshinryuninja]

Lou C
Is this a cobra package or a volvo like you mentioned?

HT32BSX115
I pumped the oil into the bottom hole that the oil is draining out of in the photo above. I filled it slowly(10min) until it was just oil without air coming out of the vent plug below the trim piston.(dont know the correct term)

southkogs
Sounds like I have a lot of work ahead of me.

Thanks for all the replies so far, any additional thoughts or tips on how to remove and not ruin parts are appreciated

 

[Lou C]

Ahh well that's not good news....
if you filled from the bottom and then stopped when it came out of the upper plug by the trim piston...what you did was fill only the lower unit, not the upper gear housing! After draining you are supposed to replace the drain plug, then unscrew the dipstick in the middle of the top cover. Just rest that dipstick in the hole. Then fill it from the one by the trim piston, till it shows on the bottom of the dipstick. It should take 2 qts. After it shows on the dipstick, thread it in and tighten it. Now unscrew the gear oil pump quickly and then replace the fill plug (by the trim piston). Next unscrew the dipstick and check the level. Let it sit for a while to allow any air bubbles to come to the top. Then add just enough to bring it to the fill line on the dipstick. I hate to tell you but you probably toasted your upper gears!
That gear oil looks like it has water in it for sure. I think you are going to need to find an OMC mechanic if there are any where you are located.

https://www.crowleymarine.com/suppor...t-filling.html

from the factory shop manual....

yep this is a pure OMC dog clutch Cobra. Gonna need a rebuild based on what you are saying.

 

[HT32BSX115]

You have a Dog-Clutch Cobra

I am sorry to say that you may have destroyed the drive.

You need to drain the oil and refill it correctly though the "FILL" port, which is the middle "plug"

The DRAIN port is only for draining. If you fill it that way, it will trap a bubble inside, that, once it makes it to the top, uncovers the gears at the top causing them to self destruct quickly.

Sorry about that.

 

[HT32BSX115]

For everybody else, I will also say that there are a few You-toobers and other internet "experts" out there that claim filling from the bottom WITH THE FILL PLUG REMOVED,

THEN when seeing oil at the FILL PORT, switching to the FILL port (drain-plug replaced) and filling the rest of the way from there.

I cannot verify that this works because I never did it that way .......IT MAY WORK!!! It doesn't matter. If you simply follow the original OMC procedure outlined in the link Lou C provided you will never go wrong!

 

[Isshinryuninja]

HT32BSX115 So this drive shaft that goes into the lower end grinds VERY bad and is very hard to turn.
I have to pull this apart and see what is going on in there.

I believe you are correct on my mistake with the gear oil. I wonder what parts I need to replace this.

 

[Lou C]

The drive will have metal particles spread throughout it. It needs to be either totally rebuilt or replaced with a good used or rebuilt unit.

 

[Lou C]

Also the driveshaft bellows has been leaking water in for a while, the ujoints are rusty.

 

[HT32BSX115]

I have to pull this apart and see what is going on in there.

I believe you are correct on my mistake with the gear oil. I wonder what parts I need to replace this.

Yeah. I would agree with Lou.

The drive is "toast" Your best bet would either be to have it rebuilt or better yet, now is your opportunity to put an SEI kit on it.

Sterndrive Engineering Conversion Kit allows you to install a SEI (Mercruiser Alpha copy) drive on the back. A lot of people here have done it. You might ask in the NON-repair I/O section about it. Even including the kit, it will be similar in price to having the Cobra rebuilt, you get a 3-year warranty and you eliminate all the Cobra drama for ever!

Otherwise, you'll need to either completely rebuild your drive top and bottom. It's possible that the bottom wasn't damaged but since the oil circulates throughout the drive, the lower unit will have to be disassembled to inspect and clean anyway.

Don't beat yourself up too much over this, you have joined a VERY large club of people who have filled a Cobra incorrectly and destroyed the drive.

Many have done it and in my case, 2 separate dealers over only a few years filled my previously installed (460) King Cobra drive wrong and the first one replaced the drive (with no lawyering up)

The second one did the same thing but needed a little threat (of lawyering up) but finally replaced the drive.

In 2005, I solved it for good by pulling it all out and replacing it all with a 1997 454/Bravo III package.

 

[Isshinryuninja]

southkogs HT32BSX115 Lou C


I found what was making the noise lol I'll look into the adapter for a Merc outdrive. I'm going to take this up and get a quote repair, but I doubt they will be able to do anything.

Thanks for ALL the comments and help, I am glad to now be apart of this community.

​​​​​​​Safe boating

 

[southkogs]

Yeah ... that'll do it

The SEI isn't an adapter. You're effectively converting to a Merc system. But if you like the boat, and the budget fits ... it's a good way to go.