This is a common repair, I preformed one a couple of months ago on an '89 Cobra. The guy had just bought the boat and wanted it made "right". It had shifting issues (a common problem with this drive), leaking hoses, cracked bellows, the usual on a boat that hadn't had it's dive off in over a couple of decades. The shift cable recall on these drives had been preformed, but it wasn't adjusted properly. In fact if you don't do this right (it's a pain in the ass BTW) then you'll tear out the gear set, which is a really expensive choice for not addressing the linkage adjustment.
The drive is easy to come off, though it really helps if you have an engine hoist. An eye bolt screws into the top of the drive, so it's easy with a lift, but I've seen guys do it with a come-a-long and moving the trailer (a real Mickie Mouse way of doing things).
Disconnect all the hoses, linkages, etc. and pull it free. Replace the bellows (or you can leak fast enough to sink in just a few minutes), replace the water hoses, replace the hard/soft lines from the pump to the distribution block, replace the lines to the cylinders, clean and replace the gaskets, replace the bearing and seal, adjust the shift lever, lube the few places you have to, then reassemble.
This is a standard "extensive transom kit" and a very common set of repairs. A standard "transom kit" is just the bellows, water hose, seal and gaskets. You can do it at home if you like, but it does require a fair bit of mechanical experience and a set of tools, some most home owner garages just don't have. Make sure the big housing pivot bolts (socket head) are torqued to spec (I can't remember, but it's around 200 pounds).
The distribution block mounted behind the drive on the transom nor the pass through for the hoses in the bracket aren't commercially available. These are junk yard parts and usually not screwed up unless you take a hammer to them or cross thread them while screwing up an installation. The hoses are available at one of many online locations or can be ordered through any marine parts outlet.
Considering the complexity of the assorted tasks, I'd recommend you have this preformed at a shop. There's lots of stuff you can screw up from lack of experience or not having the right tools, such as flare nut wrenches so you don't dick up the lines as they're removed from the rams or distribution block. Without a flare nut wrench, you'll never get these lines off. Adjusting the shift cable will drive you insane, unless you've done it a few times. It's critical this is done properly too or you'll eat up a $1,000 set of gears.
In short, your drawing looks like it might work, but I can guarantee you have more then just leaking line issues. I'll bet a month's pay you have hardened, if not cracked bellows, leaking water lines, rusted linkages, leaking shaft seal and most likely a spent bearing too. Again this is typical for an OMC of that era. This drive was so bad that they only made it three years before a major revision to the King Cobra was tooled, which was to address all the issues the Cobra had. Yep, it'll cost a bunch to have it fixed, but you can drive it for another 20 years, assuming nothing else goes wrong.
05-18-2011, 04:11 PM
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