RE: DIY Bellows Replacement or Shop 2

smarks

Petty Officer 2nd Class
Joined
Mar 23, 2010
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119
RE: DIY Bellows Replacement or Shop 2

My question is: Is it any different for an OMC Cobra than the Merc?

Thanks in advance for any help as I have never pulled a stern drive.


Quote " know EXACTLY what you are facing. I just completed replacing the U-joint bellows, exhaust bellows, and shift bellows on my 2000 Bayliner 1850 Capri Mercruiser 4.3 Alpha Gen II. In fact, I replaced the lower shift cable and trim senders too, because, at 10 years old, all of these parts are at the end of their life cycle. I live in Nebraska, and store my boat inside for the winter, with the drive all the way down to try to protect the bellows from stretching out and cracking. This year, when I trimmed the drive up for the first time, the exhaust bellows groaned and pulled loose from the transom side. Time for a complete bellows replacement. Like brake pads on a car, these parts just wear out and need replacement on a routine basis. They get hard and brittle, and just don't flex like new ones anymore. If your 1995 boat is on its original bellows, consider yourself blessed they've lasted this long. Typically, the U-joint bellows will develop a crack somewhere and leak water. The water then passes through your gimbal bearing, the main bearing in the transom that supports your outdrive driveshaft, and ultimately leaks into the bilge. You notice this by a small trickle of water when you pull the plug after boating for a day. If you don't know when your bellows were replaced, then FOR SURE expect to replace your U-joint bellows, along with the exhaust bellows, and the shift cable bellows, and the shift cable, and maybe the gimbal bearing. IN FACT, Mercury makes a kit that has all of the part included, because its such a common occurrence. The shift cable needs to be purchased separately from the kit, but putting in the shift cable during a bellows replacement is definitely the RIGHT time to do it. In my case, the trim position sender was causing the needle on the dash to bounce around, so I replaced the trim position sender and the trim limit sender too. Oh, and later, I'll tell you why I replaced the lube monitor fitting in the transom, and the lube monitor hose between the bell housing and the transom. Don't make the same mistake I did. Read on.

Tools:
You will need to have some special tools. And some not-so-common hand tools.
1) ?" socket swively - a U-joint for your socket, and a 6" ?" extension - for the bellows hose clamps.

2) ?" allen wrench - this will fit the hinge pins - http://forums.iboats.com/showthread.php?t=201422

3) Exhaust bellows expander tool - in order to get the exhaust bellows clamped onto the bell housing you'll need a tool to stretch and hold the exhaust bellows onto the bell housing while you clamp it. There's a homemade tool using long carriage bolts and PVC pipe you can make to do this. NOTE: Do NOT use bellows adhesive on the exhaust bellows. It will ONLY act as a lubricant to allow the bellows to slip off. I tried twice to use the adhesive here and failed. Read postings here on the topic and you'll find the same result. The only thing I can think is that less (adhesive) is better. - or (better yet) none! http://forums.iboats.com/showthread.php?t=358490

4) Shift cable socket - a special deep 9/16" socket with a nut welded to it so you can remove your old lower shift cable and install the new one. I've heard of people welding two 9/16" deep sockets on top of one another to accomplish this, then grinding flats on the top socket that'll fit a wrench or a adjustable wrench.

5) U-joint bell housing clamp installation tool - a piece of plywood (I used ?") cut into a circle that matches the big diameter of the U-joint bellows bell housing clamp. If you want, you can make a puller for the old U-joint bell housing bellows clamp out of the same material. I did and it worked slick to remove the old clamp. Search around on here to find the images of how it works. If you look at the Merc tools and create them out of wood, it actually is pretty easy. I figured this part would cause me pain, but making the tools out of wood worked way better than I thought.

6) Drive stand - Unless you've got a buddy that likes squatting under your boat jocky-ing around a big greasy rollypolly chunk of metal for an hour, build a drive stand out of wood. It'll pay you dividends down the road. Your buddies will offer YOU beer to borrow the thing. There are posts here that show you how. A couple hours of wood work is good for the soul anyway. Plus, it'll give you a good reason to charge the batteries on the old Makita and drive home some wood screws.

Plan on replacing your drive lube monitor hose. The hose that goes between the transom and the outdrive. This little ?" hose is attached to a plastic fitting that goes through the transom. You'll never twist it off the the plastic fitting when you remove the bell housing. Instead, you break the plastic fitting off and cause yourself more pain. Instead, plan on slitting the hose at the transom so it'll break free from the plastic barb and replace it with a new hose. http://forums.iboats.com/showthread.php?t=398663

Make careful note of the placement and orientation of your bellows hose clamps. You have to know exactly where they belong, otherwise you won't be able to tighten them, or they'll interfere with the other parts that live in the bell housing. You are trying to stuff 10 lbs of **** into a 5 lb bag back there, so even the hose clamp placement can make trouble.

Don't replace the water hose unless it looks like it needs it. This part doesn't wear out, and has positive pressure from your water pump, so it rarely goes bad. Others here will tell you to just do it while you're there, but this is one instance where the benefit does not outweigh the pain. In addition to getting the length of the hose exactly right, the pain of putting it on the transom fitting and then getting it to bend just right to not bind up the other stuff back there just isn't worth the peace of mind. If it ain't broke, don't fix it.

Shift Cable - You WILL NEED help installing the shift cable sheath, and the shift cable core. Enlist a buddy (your wife can do it) to get this done. You cannot do this one alone. To install the shift cable, you have to feed the sheath through the exhaust, around the steering mechanism without damaging it. Then, you have to get the core into it, which has a 3" straight solid length which won't go through the sheath without help from inside the boat. You DON'T want to kink the lower shift cable at this point. You have no patience left! - http://www.sterndrives.com/replace_a...hiftcable.html

I've been a shade tree mechanic forever, and a motorcycle guy too. '77 KZ1000 hot-rodded. I know rightytighty leftyloosy just like you do. You can do this project, but don't expect to do it with ONLY your craftsman set. You need to get set up to do it with the special tools above. You are in the right place to find all of the particulars to do this. If I wasn't so lazy, I'd look up all the links to the bits and pieces on this forum and post them here. But then, that defeats the fun of it. Read and learn. Email me with your unknowns and I'll give you the easter eggs that I've found doing this work so you can avoid my mistakes." Unquote
 
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