Cobra outdrive noise and suddenly stopped working

[Faerbairn]

I have a 1987 Cobra outdrive mated to a 4.3L engine
Outdrive Serial # T0481818 Model # 98454

We were on the lake and the boat was running perfectly. Then I heard a bearing like rattle/noise, so I slowed us down and while we were slowing down the engine revved up and the boat lost forward propulsion. It seems like the transmission lost the connection to move it forward. I checked the cable inside & out at the top of the engine and it was securely attached for FWD - REV.

Any ideas where I should begin looking for how to fix it?

Thank you for your help.

 

[boatguya1]

Re: Cobra outdrive noise and suddenly stopped working

See if there is oil in your upper unit at the dipstick.

James

 

[boatguya1]

Re: Cobra outdrive noise and suddenly stopped working

Also with key off place boat in fwd gear, turn prop towards reverse, did you feel it grab the clutch dog? Does the prop spin and not the prop shaft? (spun hub) If the prop and shaft spin together and you feel it engage the clutch dog you'll need to pull the drive off. Possible drive or engine coupler.

James

 

[bruceb58]

Re: Cobra outdrive noise and suddenly stopped working

Also could be that you lost your coupler.

 

[sea wolf]

Re: Cobra outdrive noise and suddenly stopped working

Rattling noise, could be u-joints. When's the last time you pulled the drive to grease them? Did you smell rubber burning? If you did, engine coupler. Other possible causes, gimbal bearing, or something internal in the lower unit. You have a Cobra. Did it shift ok? If the shift system has been acting up, you got problems. Big ones.

 

[Faerbairn]

Re: Cobra outdrive noise and suddenly stopped working

The prop is turning the internal parts of the outdrive in gear, spinning freely out of gear. I can hear the internal parts as I turn the prop in gear. They sound a little louder than normal. I can hear gears/things turning all the way to the impeller cover.

I have yet to check the oil.

I did not smell anything when this happened yesterday. The engine runs fine and sounds normal with and without the drive in gear.

So, I need to pull the outdrive and look at the inside?

I have not had any issues with the shifter. Other than since I have had the boat I can only increase the Rpm's with the boat in forward or reverse. My previous boat had a switch that allowed me to increase the rpms with it being out of gear. Does my shifter sound right or faulty?

Thanks.

 

[Gary H NC]

Re: Cobra outdrive noise and suddenly stopped working

Every shifter i have seen has a release to advance throttle out of gear.
On some its a button and others you pull outward on the whole control handle and it releases.

Unhook the lower trim rams,take off the 6 locking nuts and pull the drive...
You will more than likely find the problem.

 

[Faerbairn]

Re: Cobra outdrive noise and suddenly stopped working

I pulled it apart, starting with the upper gear case cover. There is absolutely no oil in it. The gear teeth are gone from the bottom gear and now welded in to the upper gear. Both gears need to be replaced.

Bummer!

Is there possible other damage that I do not see? Is the gear case isolated from the other parts of the lower end? ie: are the aluminum shavings contained to this area?

Am I better off trying to find a used outdrive and swap it out? It sounds easier! Yes, then I do not know it's history.

I looked thru my manual to see how big of a job it is. In your experience how big of a job is it? Also, do I need a lot of specialty tools? I am mechanically inclined, but cautious about taking on projects that I might make worse. I have rebuilt engines, is it harder than that?

Thank you for all of your help and suggestions.

 

[a70eliminator]

Re: Cobra outdrive noise and suddenly stopped working

Darn that blows, when you said you heard the rattling noise it was done, can you imagine what it would have sounded like above the water!
Cobra's are tough but that tough, key word OIL

 

[bruceb58]

Re: Cobra outdrive noise and suddenly stopped working

Sorry to hear! Who changed the lube last and when? Had you checked it recently?

 

[Faerbairn]

Re: Cobra outdrive noise and suddenly stopped working

My mechanic. I heard a very slight noise the previous time I had it out. He said not to worry about it. I am quite sure it was related. Any idea the extent of the project? Time wise? ideas...?

 

[boatguya1]

Re: Cobra outdrive noise and suddenly stopped working

All the brgs and the gears in the upper will need to be changed along with flushing and inspecting the lower. Less than one day with the parts and special tools there by someone who knows what their doing.

James

 

[bruceb58]

Re: Cobra outdrive noise and suddenly stopped working

How long ago did your mechanic change the oil? If it was recently, he may have been responsible for this.

 

[a70eliminator]

Re: Cobra outdrive noise and suddenly stopped working

Yes, Cobra's are tricky, there are proceedures for refilling gearcase, if not followed correctly you end with a less than full gearcase, I imagine your looking at a pretty coin just for the parts to fix it.

 

[sea wolf]

Re: Cobra outdrive noise and suddenly stopped working

You'll need special tools in order to set gear backlash, & to shim the new gearsets properly. If it was me, I'd be looking online for a rebuilt drive. Just set it in, do the cable adjustments & you're good to go. Iboats is one source. I don't want to blame the shop that worked on it, but I'd be looking at them to at least help with the cost. Not only that, but you are partly to blame for not checking the gear oil before you went out. Sorry, just my $.02.

 

[Lou C]

Re: Cobra outdrive noise and suddenly stopped working

Just by reading your description I was betting that there was no oil in it...what happens is if you fill the Cobra from the bottom drain hole, it causes an air bubble to form..and then you think it's full, but it's not...the standard Cobra takes about 64 oz of gear oil...It is supposed to be filled not from the bottom most hole on the lower unit (lower drain) but from the hole that is near the joint between the lower and upper units on the same side...you unscrew the dipstick and let it just sit in the hole (top cover) and hook your gear oil pump to the fill hole...pump slowly until you get about 2 qts in it.Keep checking the dipstick...then when full screw in the dipstick to create an air lock and disconnect the gear oil pump and replace the fill screw...Let is sit for a while and double check the level to make sure it's right.

I did mine when I first got it years back and I had the OMC manual so I learned the right way....it's suprising how many people have screwed up this simple job!

I agree you need a rebuilt drive....unless you have a mechanic like I do who can still rebuild Cobras in his shop....

 

[HT32BSX115]

Re: Cobra outdrive noise and suddenly stopped working

it's suprising how many people have screwed up this simple job!

Yes it is. (everybody is probably getting tired of my old story)

My brother bought my 87 Liberator new with the 460 King Cobra. Several years ago he took it to a Four Winns dealer and they "changed" the drive oil.....but didn't bother to refill it.

Boat made it about halfway around the lake when the drive seized.

Next time, he took it to a different dealer that filled it like a Mercruiser (from the bottom) It made it a little further around the lake this time.

Both dealers replaced both respective drives with no "Lawyering Up"

Bottom line: either do it yourself or make absolutely sure that your "Mechanic" knows what he/she's doing with a Cobra!


Cheers,

Rick

 

[sam60]

Re: Cobra outdrive noise and suddenly stopped working

Also with key off place boat in fwd gear, turn prop towards reverse, did you feel it grab the clutch dog? Does the prop spin and not the prop shaft? (spun hub) If the prop and shaft spin together and you feel it engage the clutch dog you'll need to pull the drive off. Possible drive or engine coupler.

James

I just bought a clean 93 Seaswirl 250 SWL-454 King Cobra and the co-worker that sold it to me said it needed a starter. I think that he hoodwinked me.

I pulled the plugs (it's been in storage for 3 years) and lubricated the cylinder tops, left for 6 hours and can't get my breaker bar to crank the engine (368 hours). I put the shifter in forward and the shaft and prop turn and stop as described above. What is broke?

Thanks,
Mike

 

[HT32BSX115]

Re: Cobra outdrive noise and suddenly stopped working

I just bought a clean 93 Seaswirl 250 SWL-454 King Cobra and the co-worker that sold it to me said it needed a starter. I think that he hoodwinked me.

I pulled the plugs (it's been in storage for 3 years) and lubricated the cylinder tops, left for 6 hours and can't get my breaker bar to crank the engine (368 hours). I put the shifter in forward and the shaft and prop turn and stop as described above. What is broke?

Thanks,
Mike

Howdy Mike and welcome to iboats!!

It will REALLY be better if you start a new thread with a new description instead of tagging on to a year old thread ......

 

[sam60]

Re: Cobra outdrive noise and suddenly stopped working

Will do.

I didn't even think about looking at the date.

Thanks