Who's Worked On OMC Cobra Outdrives?

[Chromaflage]

Has anyone worked on these? I have some maintenance questions that I need answers to - namely involving removing the outdrive. I have books, but they don't answer the questions that I have. I'd like to talk to someone who's done this. Any help?

Thanks

CrF

[Orca]

I've had mine off a few time. Comes off easy, goes on a little harder.

Will be helpful to remove the prop first to get it out of the way.

Outdrive vertical and barely touching a piece of wood or other soft material. Remove the the nuts for the tilt cylinders and remove cylinders from the drive and bungee up out of the way, but don't stress the hyd. lines.

Shifter in neutral, remove the 6 nuts, tap with rubber hammer side to side till she cracks open, then pull back. You can raise/lower and wiggle as needed using the bear-hug method. Move drive off to the side and either lay down or propup (tie) it to a post or something. That's all that holds it on, the 6 studs and the hyd. cylinders.

The gasket kit contains a new main gasket, drive shaft o-rings (2), and water inlet o-ring.There is an OMC gasket sealer for the main gasket, and a bellows sealer for the drive shaft bellows. You could use a permatex non-hardening gasket sealer and there are generic bellows adhesives available.

You will need an alignment tool to check the gimbal/motor alignment before you put it back in. I have one I could share, but it weighs a bit for shipping.

When you put it back on, it will go aways then hang on the shaft teeth heading into the motor. You will need to reach in and turn the drive shaft to try and get the teeth to mesh. A bit frustrating, then it will finally just drop in.

I have the OEM manual, which is much better than the Seloc. I don't think these are available anymore. You could have a peek at this also.

[Chromaflage]

Thanks. Do you have to remove the bellows or disconnect any shift linkage to remove it?

[Orca]

Nothing else to remove. All the bellows and the shift cable connect to the pivot housing which stays mounted to transom. The shift arm in the pivot housing just mates up with the shift rod in the drive. It will drop right out and go right back on if both are in neutral.

Once the drive is removed, you can change bellows and shift cable without removing the pivot housing. To put in a new water line up to the motor I think you would have to remove the pivot housing. Pivot housing removal is easy too, but on mine the pivot bolts stripped and I had to do some helicoiling. So, I have the tap and coils for that also.

[Chromaflage]

I appreciate everything so far - sounds fairly simple. Another question - is there any trick to separating the lower unit from the upper gear housing - more importantly, is there any trick to putting it back together?

Thanks much!!

[Orca]

Nope, upper and lower seperate real easy. If you order a new full drive, the upper and lower come seperated. Without looking at the manual, I recall the driveshaft staying in the lower, and there being a tube (water pickup me thinks) and some o-rings connecting the 2 (other than the drive shaft). The shift rod stays in the lower and has no physical connection to the upper. I will look at the manual to verify, but I believe you unbolt between the two and they just fall apart - with no loose parts to find after you hear them ping off the floor.

After cracking the two apart, you are supposed to pressure test them after reassembly. I didn't and have had no problems, but I can see how this step could save you some trouble if you find out you have a bad seal on the shop floor rather than offshore. I thought this would be difficult to do, but now think it could be pretty easy. If you have a compressor, pressure regulator with guage, and a shutoff valve, you can get it rigged up to the drive, pressurize it, then wait the allotted time to see if it bleeds off.

There is supposed to be a pressure test and vacuum test of the lower, then of the whole drive after both halves are put back together. If you have a low pressure regulator and vacuum pump (15 in), you could do this. Lower is 3-6 psi, then 15 in vac. Full drive is 16-18 psi, then 15 in vac.

I have a PDF for you.