Wednesday, May 1, 2013

Hauled, Tranny in, bruised and battered

It's now been a few days since I hauled Aeolus out, and I am just now beginning to not feel bruised and somewhat broken. It's not that I incurred injuries hauling her out myself, no, not all 16,000 blessed pounds of her myself, but once she was out, I entered a torture chamber of physical abuse. My main task was to replace the original Hurth transmission with the new Twin Disc MG 360 that I have written about here before.


My first day went smoothly, and all things considered, could not have gone better. I had the yard pop the prop off, and then I hoisted the engine up off her mounts. This is a tedious process, in that you must make sure to disconnect everything that would otherwise get torn. Fuel lines, water, electrical, battery cables, and all the rest.
A Gulf 32 keel. 6,000 pounds of lead!

To do this, and this is prelude to what I did all weekend, I have to more or less lay myself down on the floor and cross beams to access things down deep in the bilge where the engine resides. Part of the great design on a Gulf 32 is that the engine is down deep and easily accessible from all sides because it lies directly under the floorboards of the galley and navigation area. This is the good news. The bad news is that it gets a rain of dirt and dust down on it that prevents cleanliness and it is DOWN below, which means you have to lie down and reach down to reach things.




The set up. The floor boards removed. The come along

Once I got the engine up, I was able to pull the shaft out forward with the coupling still on. This was far easier than taking the coupling off and pulling it out back. Since I had to take the shaft in to be cut down by 3.02" anyway, it was no problem. So I got the engine up, the shaft out, and then started to remove the old transmission, which to the best of my knowledge had never been removed since commissioning in 1988. It was quite straightforward, and presented no particular difficulties. There are 8 bolts that hold the bell housing onto the engine, and with these removed, the bell housing and tranny come off together. I had to use a separate line to hold the weight of the bell housing/tranny so that I could ease it off the back of the engine.

Once it was removed, you can access the inside of the bell housing which gives you access to the bolts that hold the transmission on. One step, two step, red step, blue step, and then you are done, and have everything off.

Everything up to here went great. I was a bit tired, and sore, from crunching my body into hard shapes and places, but all was well.

Fortunately, the new transmission fit the bell housing perfectly, and I was able to mount it easily back onto the engine with no trouble. Now came the moment of truth. Lowering it back down to see how it fit into the space. Mind you, I had measured everything several times and had reason to believe it would barely fit.
This is the placement of the 4X4 for lifting

Well no luck. I dropped the engine back down onto the new engine mounts I had also installed (a simple and unremarkable process) and what did my wondering eyes discover but the head of the shift arm bolt was wedged up against the side of the hull and was actually preventing me from lowering the engine all the way down.

Pause. Breathe. Look again. Pause. Breathe. Mutter. Curse. Look again. Stifle anger. Calm thoughts. Make plan.

There was no way around it. I would have to make room in the hull for the new transmission, because the original hull layup had been for the Hurth, which had the shift arm on the starboard side, and the Twin Disc, for some ungodly reason, has the shift arm on the port side. The hull was built with a bit of extra space for the shift arm on the starboard side, but not on the port side, and I hadn't noticed this in all my measuring. I had assumed they were symmetrical, more or less, when in fact there was a good .5-1" less space on the port side.
Bell housing and Hurth

I sat down and pulled out a pad of paper, and began to diagram my options. I could move the motor mounts forward by a total of 1.5", and this would require pulling out every single stud and replacing them in new spots anchored sufficiently for the bolts to do their job. Problems with this approach included the fact that it would still not give totally adequate room, and would be a very painful and laborious process to move the studs. Another option was to simply cut out a dinner plate sized hole from the side of the hull, and to then craft a new hull form there to blend it all back together. This would be a very elegant way to do it, and in many ways, probably the easiest thing to do. You would have to do a hell of a lot of epoxy layers to replace the 1.5" hull thickness and to bevel everything out to the required 12:1 ratio you would end up with a  large working area indeed. In the end, I decided to take a different approach.

I decided to work on the inside and grind away the hull as much as was necessary to free up the shift mechanism, and then, depending on how much I had to remove, I would add thickness to that area of the hull on the outside with layers of epoxy and glass.
Old damper plate. Looked rusty, but OK.

I'm already tired of typing, and I haven't gotten to what about killed me.

I had to lift the engine up about two feet to give me access to the problem area. Then, because the engine was lifted up, the were no floorboards in place. No place to lay down. And the ropes and come along doing the lifting prevented me from using the middle part of the area. So I had to wedge my body sideways between the come along and the boat hull, laying myself bodily on top of the coolant reservoir, to lay just my chest on the fiberglass area behind the engine, so I could reach one arm through the engine area, the other through an access hatch toward the stern, and with a dust mask and a headlamp, reach down as far as I could with my grinder and 40 grit paper and start grinding away at the hull to make space for the transmission.

Doing this once: fine. Doing this five times: OK. I did this for about 8 hours. I could only work in about 3-5 minute bursts, and then I would have to painfully extricate myself, bashing elbows and knees and hands, to lower the engine down again to see if I had made enough room. I certainly didn't want to take away any more hull than I needed. And so this took forever and ever.

Lowering the engine involved moving hoses and other crap out of the way, getting it low enough to engage the motor mounts, and then making sure the motor mounts were lined up correctly and then easing her down. All the while cranking on the come along to move her maybe 1" at a time. The raising and lowering took far longer than each grinding session. I took to using my Dremel tool to dig deeper holes faster, but then I needed to use my disc grinder to smooth things out.
Finally!

I'm happy to say, that all this pain and effort resulted in the transmission fitting perfectly and I got the cables all attached and the new shift plate installed and the whole thing just looks dandy. When I got home I was so sore and exhausted that my poor wife couldn't even touch me as it hurt everywhere. I'm no stranger to hard physical labor, but this was about the most grueling physical suffering I've had to endure due to the wicked specific repetition of the same painful positions.

I will return this weekend with the newly cut shaft and put everything back together and align the engine and shaft and get her ready for going back in the water.

If I have any extra time, I still really hope to accomplish some painting.

4 comments:

Toad said...

Thanks so much for documenting this process! I've a one-off 40' sloop built in 1996 that I'm caring for. She was built to race, so things are spartan and tight in the cabin. At some point, I'm going to need to do what you've just accomplished. I was mapping the details from your experience to my particular situation, and making notes on what to do and what to watch for. Thanks!

Brian W. said...

You're very welcome, that is a core purpose of this blog. Feel free to contact me if you have specific questions.

Fellow Boat Owner said...

Brian,
How is that Twin Disk working out? I've got a ZF 15M that is working right now, but keeping an eye out for a replacement for the day when the Hurth dies.

Brian W. said...

The Twin Disc has worked flawlessly, and I have several hundred hours on it now. Very happy so far. Good luck with your set up. It's a major expense and surgery, but necessary!