I have some vibration in the drive shaft (visible at the stuffing box) and the v-drive moves fore and aft a bit.
Over time, I have done the following:
1. Removed the two-blade propeller and had it checked by a propeller shop.
2. Replaced the original bronze propeller shaft with a new stainless steel shaft. (The flange was also checked at this time.)
3. Replaced the strut and cutlass bearing (The strut was corroded by electrolysis - the installation was done by a reputable boat yard).
4. Aligned the engine to the v-drive.
5. Aligned the propeller shaft to the v-drive.
6. Replaced the two-blade propeller with a Campbell Sailer three-blade propeller.
I think the v-drive is OK, but has not been rebuilt. It may have about 1000 hours.
Does anyone have any suggestions?
Do you get smooth operation in the drive shaft and v-drive? I was told that with such a long prop shaft, some "whip" might be expected.
Hi There,
I tried a lot of stuff, the shaft is still vibrating.
I believe the question is: is there anyone who does not experience this "inconvenience" ?
Philippe
I did a survey of some owners I know and some said that they did not observe any significant vibration. A couple of people said that they found the flange at the inboard end of the prop shaft to be the problem. One boatyard installed a second set screw which helped, and another owner rotated the flange 180 degrees to fix this.
I talked to Walter Machine about this and they said this should not happen if the flange fits tightly on the shaft.
I ordered a new flange from them to try out. They also have the original steel L brackets used to mount the v-drive and I bought a set to have spares.
I bought a dial indicator and here is what I had planned to do next:
1. Use the dial indicator to measure the prop shaft run out. (There will probably be excessive run out caused by a bent shaft, faulty prop shaft flange, or misaligned prop shaft to v-drive flanges.)
2. Unbolt the prop shaft to v-drive flanges.
3. Turn the output flange at the v-drive to check for noise or play in the bearings.
4. Do the flange alignment procedure as described in the manual (.003 inch tolerance).
5. Re-assemble the flanges.
6. Check the run out again. If it is the same, the prop shaft flange or prop shaft are at fault.
7. Unbolt the flanges again and replace the prop shaft flange with the new flange.
8. Perform the alignment procedure again.
9. Check the run out, if it is still there, the prop shaft may be bent.
Note: When I sent this to them, Walter Machine said to measure the run out with the flanges disconnected. With the flanges bolted together, they said a prop shaft problem may not be observable. However, I am not sure if it is possible to measure the run out with the prop shaft disconnected. I don't know a lot about this. They discuss a way to check for prop shaft problems by checking to see if the clearance with the v-drive flange changes as you turn the shaft. This would of course also show prop shaft flange problems too.
It seems that the proper diagnostic steps should be able to isolate the problem.
Walter Machine did say that they normally recommend no more than 24 inches between the v-drive and prop or strut. We have about 72 inches in our boats. They said some "whip" might naturally occur.
Richard,
I had a bad wobble in what appeared to be my prop shaft as well. The V-Drive even moved while under power. The brackets that held the V-Drive would bend. I assumed the drive shaft was bent due to the difficulty of placing the rear sling when hauling.
I let it go the first season and last spring pulled the shaft. To my amazement the shaft was straight as an arrow. It had been replaced already because it was a stainless shaft. To check, you just have to roll it on a very flat surface and you will know immediately. I then looked at the flange on the prop shaft. I spun it in a lathe and indicated it with a dial indicator. It was fine. Just to be sure I took a face cut of about .002" but it cut concentrically so I knew it was right to begin with. I also took the prop to a prop guy and he said it was fine (three blade). I then suspected the flange on the output shaft of the Walter was bent so I indicated this while turning the drive shaft by hand. It too was right on.
This was all very strange as the whole assembly moved noticeably at any RPM.
I did what any good mechanic would have done, clean everything up and reinstalled. While reinstalling the flange back onto the prop shaft, the key was difficult to slide in. I had to tap the flange on. When I slid the prop shaft up to the output shaft of the Walter everything looked fine. It wasn't until I started installing the bolts that I noticed they were finger tight until I got the inner surfaces of the flanges to touch The flanges were touching but not all the way mated and the bolts got tight to turn. There was still a gap but the bolts were tight. As I tightened them with a wrench, I would spin the shaft and noticed the wobble start.
What it turned out to be is the key in the prop shaft was to long and bottomed out on the end of the key way. Or... the keyway cut in the prop shaft was cut too short (same effect). The key stuck out past the flange ever so slightly causing a high spot. As you tightened the bolts the key held its ground but the flange pulled home crooked. I filed the key shorter and the flanges matted right up tight by hand. Now the bolts went all the way in by hand.
This was a real weird deal and it took a bit of luck to find it but yours could be the same. My prop shaft, drive shaft and V-Drive run smooth and perfect. It was an amazing transition. Hope you find it.
Good sailing... Dale Tanski
Dale, that's was a great, suspense-filled story, with happy ending! You followed a thorough, scientific approach.
You are the third person I have heard from that had a vibration problem and found it was the prop shaft flange.
I use to have a nice long email list of all the P365 owners from the old site, but sadly the "name@pearson365.net" email address no longer works for most of them. However, a few got back to me from my mass mailing on this topic, and I found that: a) it is possible to get a smooth ride (despite the length of the shaft), b) the flange was a problem in two cases.
I have not pulled the shaft to check it, but am hoping it is OK since it was new two years or so ago, and I am sure the boat has not been picked up the wrong way since then. If it is not straight, it would have had to have been bent upon delivery from the prop shop where I bought it.
The strut and prop are also new, and the cutlass bearing is OK. The boat is in Mexico, so my diagnostic options are a bit limited by what is available down there (is there a flat surface at the boatyard??) and my extremely limited Spanish skills.
I have a dial indicator now and will check the flange on the v-drive, as well as the rest. I ordered a new flange from Walter Marine and can use it. But now I will also be sure to look at the key too.
Did you try to set the spacing between the flanges for .003" all the way around before you checked all the parts?
Do you think there is any way to check the run out on the prop shaft with it still in the boat, apart from the procedure that Walter Machine suggests?
Last Thursday I found that our shaft appeared to be bent. It actually rubbed the shaft tube on the inboard side. I had just reinstalled the shaft after changing the cutlass bearing. I already had the prop and zincs on it too. I pulled the shaft back out and rolled it- it was fine. Inspecting the flange, I found that the counterbore (or pilot bore) in it was damaged. It looked like the pilot and counterbore did not quite line up when I bolted it up. The flange on the vee drive was OK. I brought it home and chucked it up in my lathe. I recut the face .005" and cleaned up the counterbore. I also deepened the counterbore .060" It all went back together fine. I lost most of the day Friday getting this fixed. We should splash Monday.
Well, that's four people now that have found mysterious shaft vibrations and traced to the prop shaft flange.
Thanks for the post.
I got a replacement flange in the mail this week from Walter Machine, but my boat is in Mexico and I will have to wait for another month or so to try this out! I visit it in La Paz every three months or os.
Ray... way to go! I would think that you have solved your problem. Yet another extremely technically competent Pearson owner!
Richard... I did not try to measure the gap with feeler gages on my coupling flanges as I thought it was all in the shaft. Once the wobble was gone, I was on to yet another project. It does not appear that the flange alignment is designed to be adjustable. The two flange halves nest into each other and pull up tight together on the inner flange mating surfaces.
I do not think you can effectively measure the run out of the shaft while in the boat. If you have a magnetic mount for your dial indicator, you could check the O.D. run out of the output shaft on the V-Drive and I would think the inside step on the flange as well. You must disconnect the prop shaft to do this. I suspect with careful observation you might see something a miss and correct the problem without pulling the boat if indeed the shaft is not bent.
By the way, the first season we pulled the boat I had a heck of a time positioning the rear strap. I kept spinning the shaft by hand while the travel lift operator put some load on the strap and it kept locking up. Finally after about 6 tries he picked it up and the shaft spun relatively freely so I gave him the big thumbs up. Once the boat was clear of the water, we could see the rear strap was directly on the prop strut. I was not concerned about bending the shaft as I thought it was already bent at that time, but I was a bit concerned about the integrity of the strut. The boat was transported hundreds of feet and set into the cradle via the strut. After the strap was out of the way there was not a bit of indication of movement of the strut relative to the hull. I guess my strut is sound. It has been a full season since that lift, and I checked it last fall to see if there was any indication of movement, still no sign.
Good Sailing... Dale Tanski
Dale
It is possible to adjust the alignment of the input shaft to the v-drive, and also the output flange of the v-drive to the flange on the prop shaft. This is described in the Walter V-drive manual.
For the input shaft alignment Walter Machine makes a special tool to check the clearance at the v-drive. You have to move the engine to make the adjustments.
For the output flange to the prop shaft flange, a .003" tolerance is needed, and you have to loosen the v-drive mounting bolts and move the v-drive. Needless to say, this is not easy!
It is good that your system lined up without having to make these adjustments.
Ours ran smooth as silk moving from the yard to our slip, about a mile.
In realigning the drive on our boats, you have to remember the prop shaft makes the rules-It is not moveable. The V drive must be aligned to the prop shaft first, then align the engine shaft to the v drive. If you align the engine to the v drive first and then have to move the v drive to align to the prop shaft, you will have to align the engine again.