misalignment in shaft log overheating stuffing box

[Bfenske]

Need some advice on the proper steps here to possibly realign my shaft on port engine or, if i can get away with a longer rubber hose over the stuffing box. Description of the problem with my limited knowledge as follows:

1. Rubber hose for packing body & gland was leaking badly on side mounted to top of shaft log. With boat on lift, I unclamped hoses, slid rubber hose up shaft and found that hose by shaft log was guppied out on bottom and it looked like it was chewed up by a shark.

2. looking at the shaft going through the shaft log, it was not centered very well. It appears that it was not touching anywhere but the shaft was low of center vertically and right of center horizontally. I could fit the tip of my pinky finger on the larger side and barely a fingernail on the side where the shaft was closer to the shaft log.

3. I was able to turn the shaft by hand, and it did not appear to have a wobble to it. In addition, the motor does not vibrate even at high rpm's.

4. Since I have no experience removing the shaft from the transmission coupling, I cut the hose for the stuffing box shorter to remove the chewed up portion of the hose.

5. After remounting shorter hose and running, I had trouble getting proper flow through the packing gland.

6. My next step was to find a packing puller and i pulled 4 old wraps out of the packing body and rewrapped 4 new ones with the proper packing material. I was advised by a friend to miter the ends.

7. The packing was very difficult to push into the annular space on one side of the packing body and much easier to push in on the other side. I'm assuming that this is because the shaft is nowhere near dead center causing more pressure on one side than the other.

8. We took it for a short sea trial and we had plenty of water flow through the packing gland but I guess the shaft being off center of the shaft log was still producing heat. The shaft was cool, but the packing body and gland got very hot to the touch only after running on plane for a few minutes.

Ok there is a detailed description of what i have on my hand and now I'm looking for some ways to fix the problem without creating a bigger problem. I'm thinking the cheapest fix is a longer hose but that is probably more of a band aid than a permanent fix. Any help on how to align the shaft more center line of the shaft log without me screwing more things up would be appreciated.

[Harry Babb]

I suggest that you just raise the engine and scoot it to the left enough to center the shaft in the shaft log. Its not terribly hard to do but the help of an experienced friend will certainly do you good.

I am saying this ASSUMING that you DO NOT have intermediate bearings on your shaft. If you do have intermediate bearings then things are gonna get a bit more complicated. You will have to pull the boat and realign the strut, intermediate bearing, and the shaft log to one another then set the engine alignment to the shaft.

When I remove the shaft log from the port side of DeNada I discovered that the shaft had been rubbing the shaft log and actually worn about 25% thru the shaft log wall.......but she did not have any signs of vibration

When you install new packing be careful not to over tighten it at the beginning. After installing the packing I leave it quite loose and of course it leaks. Then I run it a bit and gradually tighten it up and run it some more and repeat the routine until I get it where I want it to be. When you are done the packing box could be a little warm but not uncomfortable to touch and it should also leak a drop or so every minute.

Harry

[Carl]

Ditto to what Hary said. Try to have shaft lined up in the srtut, log and aligned to engine.

Couple other thoughts

-Did you install standard Flax packing? Looks like rope and wax.

-Generally I prefer three rings of packing, mitered and placed in gland with the joints @ 120 deg. As they seat and wear into place over the next couple seasons the 4th can be added.

-By any chance did you look at the shaft condition where you wound up putting the packing gland? If you had wear there, you have to overtighten the packing to get it to drip properly which in turn creates overheating and leads to more shaft and packing wear.

-I didn't see where you mention how short the log hose is now, but I like a couple inches of hose between the log fitting and packing gland.

[In Memory Walter K]

I will bet it's your engine out of allignment. The coupler faces when you tighten the 4 bolts that hold the shaft to the tranny should be exactly flush with each other. Use a feeler gauge to make sure the space on all 4 sides is the same. The adjustments are made by slightly raising or lowering the corner of the engine that will adjust that coupling face to fit your need. The engine mounts usually have a big bolt on top (to lock things down tight). The bolt underneath that can be turned one way to raise and one way to lower. Once you've adjusted it so the couplers are flush, lock down the top bolts tight. The hardest part is often the location of one of the mounts, and rust that develops over time. I suspect your engine's vibration loosened one of the mounts and over time has been creating your situation. Walter

[Bfenske]

So, if I decide to try moving the engine to align the shaft center of shaft log, I uncouple the shaft from the tranny? Can it be done without uncoupling if I leave everything together (besides the rubber hose around packing and shaft log), loosen up the motor mounts and adjust to center shaft log that way?

one other thing to note is one of my motor mounts is rusted up pretty badly (port side of port engine) so that may have been the culprit. I plan to clean the rust and to start using the anti corrosion stuff you guys keep raving about. Thanks for the comments so far. If it is rusted really bad, I may have to replace that motor mount.

I left the packing pretty loose so far and I bought the more expensive 1/4 " darker marine graphite looking packing (same material Dave had previously). Instead of a few drops per minute, I have a small continuous trickle at the moment. I made sure to rotate the miter cuts at different 90 degree angles.

[RussP]

The shaft may never have been centered in the bronze shaft log. Just pushing the engine over is not necessarly the answer. Chances are if the engine beds are original they are punky and soft and unable to hold the lag bolts. If the hose for the packing gland is original it should also be replaced. The shaft should be easy to turn but a worn out cutlass will allow a out of alligned shaft to turn easily. It might be time to bring the boat into the new millenium and rebuild the engine beds and glass in a new shaft tube and install a dripless seal. This is a area that should be addressed as many a boat went down because of packing gland problems.
The only place you could get a true alignment check is in the water with the boat sitting in its natural position.
RussP

[Harry Babb]

So, if I decide to try moving the engine to align the shaft center of shaft log, I uncouple the shaft from the tranny?

Yes you must disconnect the shaft coupliing from the gear! !

Can it be done without uncoupling if I leave everything together (besides the rubber hose around packing and shaft log), loosen up the motor mounts and adjust to center shaft log that way?

Absolutely not! ! There is no way to know if you have the shaft in a bind doing it without disconnecting the coupling. As Walter said, in the final analysis the coupling faces must be very parallel. I don't know how ZF wants them but the old Borg Warner Velvet drives are to be aligined to within .004" Max out of parallel.

Russ is right.....if the beds and stringers are deterioated you will never be able to maintain alignment .

Do you know if your 31 has the intermediate shaft strut bearing?

Harry

[Skipper Dick]

Just to add to what RussP said, if you leave your boat on a lift as I do, the hull tweaks a little and conforms to the bunkers it is sitting on. My bulkhead door fits pretty tight and sometimes when the boat is on the lift, it rubbs on the threshold a little, but it works good while in the water.

So if you put the boat in the water to align the shafts, just leave it there for about 6 hours to let it reshape itself to it's correct anotomical position. Then with the coupler removed from the transmission, you can use a feeler gauge to determine if there exists to be an angle of +- 2 thousands (I think). Lots of alignment info on the abandoned site.

Then again like RussP said, your engine may be sitting on mushy ground.

Dick

[gplume]

Bfenske-

Spent a lot of time dorking with mine the first year i got the "project" in the water. Could never get it right.

After the first season, having had all else fail just pulled everything out. (shaft coupling removal method - use sockect for a spacer, and just walk it off.) Had the props trued, the shafts checked and one straightened, and had the couplings faced. Put every thing back together. Waited until the boat was in the water sitting for a few days, and used the rule of .001" per 1 inch of coupling diameter. Actually got it dowm to about 4 mils on a 5' coupling.

No problems since.

End of the day advice - everything has got to be just right for you to get perfect alignment. (I had relatively new motor mounts, so that was not a concern, take heed to the guys advising you to check the mounts.) I bought a hydralic "wedge" jack to walk the engines around for alignment purposes. A big help. though I have seen a pry bar used.

[Bfenske]

Well, I went down to the boat again today and I definitely found the problem. the back port motor mount is structurally (rusted through) starting to fail. When these mounts were originally installed, someone put a small wood screw as a marker on each corner (diagonally on each mount). The upper portion of that motor mount has moved 1/4" to 3/8" toward the center of the boat and that is the same way the shaft has moved. The crazy thing is that there was only one lag bolt on both back motor mounts (back only). There should have been two lag bolts per mount. Looks like I've got a big job on my hands. The engine if you look at it closely actually looks crooked towards the center of boat from behind.

My plan is to replace the back two motor mounts, put two lag bolts per mount and hopefully move the engine and shaft where they belong. I've got some friends who have jacks, port-o-powers and large pry bars. . Obviously I want to displace any weight away from the hull and use the stringers as areas to apply pressure with pry bars or jacks to avoid damging the hull. Any advice you guys can give so I can do it safely and correctly would be appreciated.

[randall]

well at least you dont have V-drives. i gave up after ten hours and got a marine mech friend to help. remember everything has to line up...not just the engine to shaft but all the way to the prop. the biggest help i found was having the mounts really easy to adjust. it gets micro and a balky mount will drive you nuts.

[Bfenske]

Update: I had to replace all 4 motor mounts and now I need to move the engine to align the two couplings together for tranny and prop shaft. I've got two port o powers ready to try it tomorrow. The engine is at least 1/4" to 1/2" off towards the center of the boat and it is my port engine.

One of the old mounts was rusted out completely and another had a broken bolt where it mounted to the engine! Several old lag screws were not Stainless and broke apart when I tried to unscrew them.

Some particular advice i'm looking for is "facing" the coupling and/or "bonding" the coupling with wire. Just saw the terms on a few web pages and wanted to get some advice before heading down from some veterans.

Wish me luck :shock:

[chris pague]

My Q is Who put in and when were the Vullllvaas installed? How long have you owned the boat and maybe or likey why where the engine mounts not replaced and the time of the engine repower?

[Rawleigh]

"Facing the couplings" means taking both halves of the coupling to a machine shop and having them face them off in a lathe so that the flange faces are true to each other and you can get an accurate reading from the feeler gauges. Any small burs can make it impossible to align.

If you don't have rubber spacers in the couplings you don't need to worry about bonding them. The metal to metal contact will do that.

[Bfenske]

My guess is the mounts were 20+ years old. They were not factory motor mounts from volvo penta. My TAMD 60C's were built in the 80's. I spent all day this past weekend trying to line up the engine to the shaft with no success. The whole engine definitely moved inward towards center of boat because the two worst mounts were on the port engine, port side. one was rusted so badly it was broken and the other had a broken bolt where it mounts to the motor bracket! They both moved at least a 1/2" towards starboard.

The problem is trying to line up the shaft in the middle of the shaft log while keeping the coupling face in alignment. I was able to do both things one or the other but I could not get both at the same time.
If the couplings are aligned, the shaft is up against the shaft log... If the shaft is centered in the shaft log, the coupling is out of alignment. The comment on this thread of it ain't easy is an understatement!

My best guess is I mounted the lags not far enough port. Where the engine was laying after it moved, I mounted the lags as far port as i could to give me some play to force the engine back to port but it may not have been enough. The boat is on a lift, and I didnt have an engine hoist to lift the engine before changing the mounts. I was able to take one mount off at a time and replace them one at a time.

[CaptPatrick]

Brian,

The only way to get the shaft log centered with the engines properly aligned is to, first remove the shaft completely from the shaft coupling, slide the shaft back far enough to clear the shaft log. Remove the shaft log and reinstall the shaft to the engine. Align the engine with the strut/cutlass bearing to within .003" - .004". Lock the engine down tight.

Now, remove the shaft from the shaft coupling again, thread on the shaft log, and position it true to the shaft and hull. You'll probably see that the original shaft hole and bolt holes no longer match to the shaft log.

Fill in the old bolt holes, make any necessary modification to shaft hole and re-install the shaft log in it's new and centered position.

This would also be a good time to get rid of the old bronze shaft logs altogether and replace them with fiberglass shaft tubes... See: Building Fiberglass Shaft Logs

Br,

Patrick

[Bfenske]

Thanks Patrick. Marsha Kosh told me to say hello to you and she appreciated what you did for Dave.

I guess my big job turned into a bigger one :(