Need help pulling engine with ZF631V V drive

Hi,
I've got a 40 ft Mainship Sedan Bridge and need to pull the port engine, Cummings 6BTA, that is mated to a Velvet drive, ZF 631IV (HSW 630V1 HSW). This is the type of V drive in which the shaft passes through transmission and is bolted in the front.

Typically, you need to pull the engine and transmission together, as disconnecting at the bell housing is problematic. There is about 6" of shaft that would need to come out, but the engine mounts make it difficult to pull it out. It would also screw up the shaft alignment, where as pulling the engine and transmission together just requires getting it back in trhe existing mounts.

Pulling the engine and transmission together requires backing the shaft back around 13" to clear it from the transmission. I dove on the prop and rudder, and there is only about 7" of play for the shaft to back out. The spec for this transmission show I need 13". Even if I pull the prop, I still only have about 7" of play.

What do I do ? I cant pull the rudder, because this need to be done in the water without hauling the boat.

Help !

You can pull the rudder. You just need to be prepared to block off the hole. Your bilge pump should be more than enough to pump any water out. You can rig the rudder to hang as long as it's well secured. Once it's hanging, it should move enough to let the shaft squeeze by.

Don't expect the engine to be inline just by setting it back on the mounts.

Man, I was really hoping to avoid that. I was going to take a couple of weeks to rebuild the engine and hate to have the rudder out that long. How do I remove the rudder? There is like a packing box that it goes through, right ?

Usually no big deal to drop a rudder. One guy in the hole to disconnect hardware holding it up, a diver down below to catch it. Tapered plug(s), either on the inside (or outside, or both) to keep water out. Once engine is out, put the rudder in temporarily, or a piece of shaft from a machine shop to be a more permanent plug while rudder is out.

Note it is much easier to pull an engine in a boatyard with boat in travel lift slings and a boom truck or fork lift extension. The boat can be positioned any way you need to get a good purchase with the crane or fork to make it work. Rudder and shaft work no big deal then.

Note the engine and gear only need to be separated about three inches to clear, maybe you can leave the gear in place.

I would love to leave the gear in place. Everybody I talk to says you have to take them as a pair. In order to pull back 3", I would have to lift it 2" off the engine mounts. Since the Transmission/bell housing is stationary, I don't see how I could get the shaft out and back in, it would be at an angle.

Here are some photo to get an idea what I am working with...

I managed to remove the end nut from the drive shaft and the coupling to the transmission. I put the nut back on the shaft and hammered on it, but it doesn't backout of the transmission. I dove on the boat and cleaned the shaft, so it should move through the strut. any suggestions? Should I loosing the packing nut for the drive shaft ? Should I get in the water and try pulling on it ?

eric

If you are trying to remove the shaft from the coupler you may have to press it out. Get a bit longer bolts, loosen the coupler and put a nut in between the front of the shaft and the output shaft on the transmission. Then gradually tighten the coupler bolts. As it gets closer to the transmission half of the coupler the shaft will be pushed out of the coupler. Then loosen it again and maybe put in a small socket with longer coupler bolts and tighten it again. Keep doing this with longer bolts and larger sockets until the prop shaft pops out. You may not get it out with a hammer. The problem will be getting the prop shaft back in the coupler. I had one we never could get back in until I had a machinist check the coupler and it had one end smaller than the other. He turned it so it was true all the way through and then it went on easily.

To solve this problem, you really need two tools; A Phone and a Credit Card.

Honestly, you have introduced two challenges here which are working against you.

1) Limited knowledge

2) You're trying swap an engine in the water.

Either one is tough, both is going to make for a very, very difficult job. I truly wish you the best of luck. I've swapped 4 engines over the years. All of them were blocked on land.

Actually, its going along O.K., Pictures attached.

The Prop shaft is sliding out pretty easy. The Rudder is unbolted, both pins are out and ready to drop. I've hit it pretty hard with a sledge hammer, but it really isn't budging. I've sprayed it down with liquid wrench and dove in the water and moved it back and forth. I will try again after work tomorrow. Day light savings time is really screwing me for getting this done.

Shrew said:

To solve this problem, you really need two tools; A Phone and a Credit Card.

Honestly, you have introduced two challenges here which are working against you.

1) Limited knowledge

2) You're trying swap an engine in the water.

Either one is tough, both is going to make for a very, very difficult job. I truly wish you the best of luck. I've swapped 4 engines over the years. All of them were blocked on land.

Click to expand...

I cant think of any reason to try this in the water other than to save hauling and 'on the hard' fees.

Think of the salvage expense if the rudder corked popped out and you were not right there. Or perhaps the boat will list as the engine is lifted off the motor mounts....

Here is an update for anyone following this thread...


I put the rudder and the prop shaft back in place. I am having trouble finding a replacement rubber port, so I will worry about it when I do the next hall out.


Yesterday I was able to pull the engine. The plan was to use the travel lift at my local marina, However, it was tied up when I arrived that morning. We ended up using a front end loaded with an extension. They pulled it up to the side of the boat where I was moored and we had it out in 1/2 an hour. The Torsion coupling was seized on the transmission shaft, so we had to pull and push the engine sideways, back and forth, until the torsion coupling broke apart. Otherwise, it came out pretty easily.



As to rebuilding vs a long block, when we first lifted the engine, it ripped out the back lifting ring by the bolt threads. There is so much corrosion on the block that the threads just ripped out. Based on that, I am going to go with rebuilt long block for some fresh iron.



Thank You one and all for your help.



Eric


Ps I am still looking for a rudder port, so if anyone knows where I can get a 1.5" shaft rudder port with a 45 degree base, please post.