omc cobra- replacing seals difficult?

[RusshasOMC cobraissue]

1987 OMC cobra stern drive failed the vacuum and pressure test(engine overheated, water in the drive). Shop wants $1300 on 11 hours to replace all the seals entire drive. Is this reasonable? I'm very handy and would like to do work myself- would I need any special tools? Many thanks/Russ

 

[sea wolf]

Re: omc cobra- replacing seals difficult?

The biggest problem u will have is when u go to reattach the pig {please don't take offense} back on the transom. See my thread. Other than that, in omc's infinite wisdom, they have designed a drive with a ton of seals in it. It's a big job, which involves a complete teardown of the drive. Get a manuel, you'll need it.

 

[pete44]

Re: omc cobra- replacing seals difficult?

To replace all seals and impeller on my alpha drive was $500..I had oil in my bilge..your quote sounds pricey .I would check around (even out of your city)..for $1300 you can just about BUY a drive...Or try it yourslf and you could end up like Seawolf..heed his warning!...Pete44

 

[RusshasOMC cobraissue]

Re: omc cobra- replacing seals difficult?

Thanks sea wolf. Would I need special tools to assemble and reassemble? lastly, is the 11 hours reasonable? Still not sure if I should take this on! appreciate your advice.

 

[pete44]

Re: omc cobra- replacing seals difficult?

Not meaning to butt in..but most marine shops charge between $75 to $100 / hour labor..I cannot believe it takes 11 hours to do this..I have pulled my drive off in under an hour (and I am a novice).....Pete44

 

[SeaRyan]

Re: omc cobra- replacing seals difficult?

RusshasOMC cobraissue it can be a big pain to fix these thing on your own I know I have had my bad days but the knowledge you gain and the money you save makes it well worth the time and pain.

 

[sea wolf]

Re: omc cobra- replacing seals difficult?

Pete, theres a lot more to resealing this drive than just pulling the l/u. There are seals, 0-rings & gaskets that will need to be changed if u really want to get anal about it. The job involves splitting the upper & lower unit, etc, etc. It's too involved to fully explain here. I think 11 hrs. is about right by the time they reinstall the drive to the transom with all that's involved with that task. Now Russ, there are 2 seals that may be the culprit. The water pump shaft seal in the lower unit & the prop shaft seal. Look at both of them before u commit to a complete reseal job. The 2 of them can be replaced without too much difficulty. Good luck. Oh, by the way. How did an engine overheat cause water in thr drive? Did someone tell u that?

 

[pete44]

Re: omc cobra- replacing seals difficult?

Russ, main thing is if you change seals(CHANGE THEM ALL)...its just a rule of thumb..And I am still stumped on the 11 hour thing..not meaning to argue...I will be talking to my mechanic soon when he aligns my drive..Maybe the $500 he charged me was just for lower half of leg only..But I recalled him saying to change all seals while he is in there..and I dont think he would try to rip me off...I have delt with him a few occasions and he has given honest advice...I have an alpha 1 drive and $75/hour rate times 11 hours dont = $500.....Pete

 

[dpbj6]

Re: omc cobra- replacing seals difficult?

I just had my upper unit rebuilt and the lower resealed. The upper rebuild was 1600 installed and the lower reseal was 300 total. 2.3 omc cobra.

 

[Don S]

Re: omc cobra- replacing seals difficult?

Pete, you really need to stop comparing what it takes to do your Mercruiser Alpha drive to what it takes to do an OMC Cobra drive. They are different.<br />As far as the 11 hours goes, if the boat is used in salt water and has a lot of corrosion on it, then it may take that long. Hard to say without actually seeing the drive and boat. There may be signs of problems that the mechanic giving the estimate sees that is going to give him problems resealing the drive, that the rest of us can't see.

 

[Lou C]

Re: omc cobra- replacing seals difficult?

Hard to say on the hrs, but they may also be adding in other parts that may need to be changed as well (water tube, bearing retainer) that may be corrosion damanged and may need to be changed to make it no leak.<br />I have the OMC factory shop manual, and changing the seals IMHO is not a job for someone who does not do this for a living, and had done many. I can't imagine that it is that much different than a Merc Alpha. What do they charge for labor?<br />Here it is $100/hr!

 

[seahorse5]

Re: omc cobra- replacing seals difficult?

The Cobra upper drive gear has to be pressed off the shaft to replace the upper shaft seal, unlike Mercs where you only have to remove a nut and the bearing pack.<br /><br />If money is an issue, have them pressure and vacuum test the drive unit and find out exactly what has to be changed at this time. Like was mentioned before, propshaft seals and shift rod orings are the most common sources of leakage.<br /><br />If it hasn't been changed for several years, have them install the new bellows assy as they are not that expensive and are easily changed. The new one has a larger opening to make installing the drive a lot easier.

 

[RusshasOMC cobraissue]

Re: omc cobra- replacing seals difficult?

Thanks everyone. I'll answer as any of your questions as I can. First the estimate is to only do all the seals in the entire drive. no other parts. I pulled the drive and brought it in. I'll have to put it back on the transom as boat is 700 miles away! Sea wolf-I hope this pig goes back on smotthly-some of these stories are killers! The engine overheated, the drive got hot to the touch and you could hear it sucking in the water..I think I have ablockage in the manifold or riser that led to the over heat issue. Drive worked perfectly, no issues except water in the oil which I drained immediately and refilled w/new.

 

[seahorse5]

Re: omc cobra- replacing seals difficult?

While the drive is removed, look up thru the exhaust area and see if the shutter valves burned away from the exhaust pipes and lodged ahead of the exhaust bellows inside the transom plate.

 

[WZNYROBO]

Re: omc cobra- replacing seals difficult?

I had an overheat problem with my omc cobra.... What is the vacuum and presure test you ran........????

 

[RusshasOMC cobraissue]

Re: omc cobra- replacing seals difficult?

Thanks sea horse, I cant see the boat as its not at the house but I'll do that next trip. When I drained the exhaust manifold for the winter nothing came out. I poked a pen up through the petcock and all the scaled rust and water then came rushing out. I'm thinking the whole cooling system needs to be completely flushed to get this rust material out. Thats probably the cause of my overheating issue?

 

[RusshasOMC cobraissue]

Re: omc cobra- replacing seals difficult?

WZnyrobo-the pressure and vacuum check was perfromed on the stern drive as I had water in the drive oil. Any marine shop can do this for you at minimal cost.