Pulling my transmission/bell housing

[tagster]

Reposting since this deserves a new topic anyway.

I found some shards of what seems to be a damper plate in my bilge while investigating an intermittent but loud racket my engine was making.

I pulled the starter to check it out, the case of it that encapsulates the starter shaft and pinion has some scaring on it. Looked inside with a mirror (which is now lost in my bilge :-)) and saw what looked like broken metal on the front of the fly wheel. I decided to go ahead and try and pull my bell housing and it's proving to be rather difficult. I'm not quite sure how I can get at it. I was thinking I would unbolt the propeller shaft, disconnect the transmission and slide it back to get off the bell housing. But I got stuck on step one.

Here is my drive shaft, with half the bolts pulled.


The bolts that are pulled run in to the left side of it (from this angle) and are nearly as long as that big red grommet. The other side has nuts, which have threaded heads coming out of that thing. The shaft in the picture runs clear to the back of the bilge and into some housing, I figure it's probably connected to the prop directly.

So even when it's good and unbolted it doesn't seem like it's going to come out unless I move my transmission forward. But the whole idea of coming from the transmission side was to do it without moving the engine.

I'm starting to wonder if that's possible

Anyway, anybody have any tips for pulling my transmission?

[tagster]

hell I just about sank my boat. I figured if I shifted that coupling back I could get some free space. I loosened up all the bolts and tried to pry it backward, but my propeller shaft moved instead of the coupling and I started taking in water.

I pulled it back where it used to be and spun it around, the leaking stopped...that was ******* scary. I'm going to have to keep an eye on that seal now.

[KeelHaulin]

Originally Posted by tagster

The shaft in the picture runs clear to the back of the bilge and into some housing, I figure it's probably connected to the prop directly.

The housing at the back of the bilge is called the "stuffing box". It seals water from coming in around the shaft; usually there is packing material that is a rope impregnated with flax or sometimes soft teflon. Some are "dripless" and designed differently than what I describe here. The stuffing box needs regular maintenance, if you have a continuous drip while the engine is stopped it might need tightening. You should tighten it until the drip just stops but it might weep while motoring; this keeps the shaft and packing cool.

You mentioned a large volume of water coming in when you moved the shaft while trying to remove the transmission. This is warning sign that the shaft packing needs replacement. The shaft should be able to slide fore/aft without a gushing in of water; it's possible that moving the shaft aft allowed more water pressure into the stuffing box (around prop and through the cutlass bearing). I would have this checked immediately; it's possible that the packing can be replaced without pulling the boat out of the water; but I don't know how your boat is built. A good boat mechanic should be able to tell you what needs to be done.

HTH...

[sailingdog]

KeelHaulin-

Just FYI—The stuffing material is a rope-like material made of flax or teflon...it isn't impregnated with flax or teflon... it is usually impregnated with grease of some sort.

[gc1111]

What happened to you is pretty normal. The stuffing box works by compressing the packing (the square rope-like material) against the shaft. As a result the shaft is burnished smooth there. When you shift the shaft, you move a section of the shaft that probably has some corrosion or other crud under the packing material. So it leaks. Stop the leak by using emery paper on the section of the shaft, moving the shaft aft, then cranking down on the packing nut to stop the incoming water. After you get everything done, you will have to repack the stuffing box so make sure you have some of the right sized material and know how to do it.
Between removing the DriveSaver and shifting the shaft aft you should be able to create enough space to shift the transmission aft and free it (be ready to support it then :-). It should only have to move 1-2 inches - at least on the ones I have seen, but I am no expert.

[SimonV]

Originally Posted by sailingdog

KeelHaulin-

Just FYI—The stuffing material is a rope-like material made of flax or teflon...it isn't impregnated with flax or teflon... it is usually impregnated with grease of some sort.

SD

The grease is normaly graphite grease, of just plain powderd graphite. There is some new stuff I saw in an English magazine, cant remember the name but it was bright green and fiberous, it got a good write up.

[Idiens]

Originally Posted by tagster

Anyway, anybody have any tips for pulling my transmission?

That looks like a BW hydraulic transmission. Are you sure you can get at all the bell housing bolts without lifting the engine out?

When you saw loose metal on the flywheel, are you sure it was loose? (not a trick of light combined with a tab-washer retaining the flywheel? And where would the metal come from? (One of the starter cog teeth? - Check by turning the engine over by hand - where is it missing from?) One of the starter pinion teeth (you would have seen that)? Nominally there is not much in the bell house (not even a bell) to break off.

[Hawkeye25]

That transmission weighs about 150 -180 lbs, so I usually find a way to rig a 2x4 over it and lash a sling to support the tranny.

Then carefully inspect any oil lines, temp sensor wires, shift linkage, and decide what has to be removed and what can just be loosened from supports to allow you to move the transmission once it's loose.

For instance, I usually pull the transmission oil cooler heat exchanger out of the water system and leave it attached to the tranny, rather than breaking the oil lines. It's less mess and less risk for the tranny. You hate to ruin a perfectly good gearbox by accidentally getting dirt in the oil cooler lines. It's rare but it happens.

Remove shift cable and electric wires and place everything up and away and safe. Then remove the tranny bolts and slide it back. Be careful. This is a good time to get smashed fingers and crush lines that you need. Take it easy, put wood blocks and maybe a piece of plywood underneath, use the sling and get the gearbox away from the bell housing.

Pay attention to detail - it makes it easier when putting it back together.

When you can see inside the bellhousing, you'll notice at least one of the damper plate springs is missing, maybe more. New damper plate - and inspect everything for other damage.

Hawk

[tagster]

Originally Posted by Idiens

That looks like a BW hydraulic transmission. Are you sure you can get at all the bell housing bolts without lifting the engine out?

When you saw loose metal on the flywheel, are you sure it was loose? (not a trick of light combined with a tab-washer retaining the flywheel? And where would the metal come from? (One of the starter cog teeth? - Check by turning the engine over by hand - where is it missing from?) One of the starter pinion teeth (you would have seen that)? Nominally there is not much in the bell house (not even a bell) to break off.

I already did that, it wasn't one of the starter cog teeth. I spin the starter around and inspected it. Part of the starter housing that fits into the bell housing was also pretty scarred up. The way I figure it, even if it wasn't a broken damper plate something was definitely flying around in there so I should probably get it off and find out what it was.

I'm not 100% sure I can reach everything without pulling the engine, but I'm sure going to try. If I run into too much trouble, I'll just call a mechanic and have him finish the job. :-)

So the "gush" from the stuffing box was fairly minor. And when I put it back, the drip stopped immediately. If that stuffing box needs regular maintenance that's bad news because it's not in a place that is accessible without taking apart cabinets and flooring.

So if I push the drive shaft backward again it should be fairly low risk? (I only plan to move it back about an inch). I could snag a photo of my stuffing box probably, but it's very difficult to get to. To even see it I have to basically stick my head in the bilge with a flash light then it sits maybe 4.5 to 5 feet away from that bilge access point.

[christyleigh]

Originally Posted by tagster

So the "gush" from the stuffing box was fairly minor. And when I put it back, the drip stopped immediately. If that stuffing box needs regular maintenance that's bad news because it's not in a place that is accessible without taking apart cabinets and flooring.
So if I push the drive shaft backward again it should be fairly low risk? (I only plan to move it back about an inch). I could snag a photo of my stuffing box probably, but it's very difficult to get to. To even see it I have to basically stick my head in the bilge with a flash light then it sits maybe 4.5 to 5 feet away from that bilge access point.

Even if your stuffing box doesn't need regular maintenance it still needs fairly regular inspection for leakage. As someone mentioned it might be a good idea to hit the area of the shaft you will be sliding into the stuffing box area with some fine sand paper to insure that there are no big ridges to mess up your packing. The leaking will probably not stop completely because you are removing 1 (the most solid) of the 3 stabilizing attachments to keep the shaft in line and in good contact with the stuffing material.