Another Stuffing Box Saga

[dclagett]

Ready to put boat in water after a long winter. One thing left to do, 45 minute repack stuffing box. I did not have the tools so I turned the job over to the yard where we winter the boat. This is the first time that I know of that the stuffing box has been repacked.

I received a call 2 days ago that they were having trouble separating the stuffing box haves. It appears when the box was put together the threads were crossed. The yard wanted to know if it was OK with me to pull the shaft back so they could get the stuffing box off and inspect it to determine if the box was salvageable. I agreed, since it is almost impossible to work in that small area on a RT25SC.

I received another call from the yard today. Now they cannot get the engine coupling off the shaft in that small area. So I have 2 choices: (1) remove the engine to allow room to work or (1) cut the shaft. I opted to cut the shaft. So now a 45 minute job and a few $$ in parts has turned into a many hour job, a new stuffing box, a new shaft and a new engine split coupling to the shaft so we do not need to cut the shaft in the future.

I wish boat manufactures would think ahead and design the boats so they can be maintained at a reasonable cost!

 

[scross]

Ouch!

 

[Brian B]

Do you have a Volvo engine?
I’m more familiar with the Yanmar setup.

 

[BB marine]

I have been talking with another Cutwater owner about a similar issue. There is limited clearance least with my D3 and his D4 in our Cutwaters. If they do get the packing nut loosened a # 0 packing tool puller is needed for clearance. There are a couple companies that make good quality pullers C.S. Osborne & co. and Palmetto. I have both. I'm told that Palmetto recently purchased have broke. To loosen the packing nuts. I took 2 adjustable Plumbers wrenches and adjusted them to the proper size of locking nut and the packing nut. I then drilled and tapped 1/4" threads installed 1/4 / 20 screws to lock them in that dimension. I filed the wrench opening to create a flatter surface and better fit to the two nuts. I have two 1' cheater bars that fit over the handles. This gives me better back up leverage to hold the packing nut while loosening the lock nut.

Next issue getting shaft out. I looked at mine yesterday. I have 2 I/4" of clearance to pull my coupler. This is a tapered shaft so it will require removing the nut and installing a puller to break the shaft loose from the coupler. The nut looks to be a 7/8 nut which would require 1 7/16 socket. The socket will need to be cut down to give room for removal of the nut. Once the nut is removed a flat gear puller plate will be needed to pop the coupler off the shaft. I'm going to make one out of 1/2 " steel plate drill a 5/8 hole in the center, weld a 1/2" nut on the back side, four holes that align with the coupling bolt holes, Thread a 1/2" bolt in the center of the plate long enough to reach the shaft, short enough to fit in between the two couplings. Bolt the plate to the coupling. This should remove the coupling. I made a puller similar to this for removing my prop. same principle. It is tight to get at and it sucks! I would rather use a little ingenuity then go through the aggravation of pulling the engine to replace packing. I will post pictures of my D3 install.


If the packing nut is damaged from cross threading , it most likely is Galled. I would not use it again. If I were working on the boat I would cut the nut off and the gland with a Metabo cut off wheel. Once removed this will give plenty of room to remove the coupler. Replace the packing gland with in like kind or replace it with a dripless. This would be much better then pulling the engine. One way or the other the gland will need to be replaced if the threads are damaged.

This shows the working area to either replace the packing or remove the coupling. It is tight. Pulling the engine in the C26 is real tight 3/4 of the engine is under the pilot house deck. My option is to make some tooling to remove the coupling. I am assuming the R25 with D3 is similar.

 

[Cutwater28GG]

take lots of photos and videos! if you want to send me any video files and photos I can get them sorted and put together and then posted for others to understand how to do this.

 

[NorthernFocus]

This is a good reminder to twist the nut on the stuffing box once in a while just to make sure it's not frozen in place. Not a problem if the packing has to be tweaked now and then but after re-packing sometimes it can go a long time without adjustment being necessary.

 

[dclagett]

Brian B - Volvo Penta D3-150

Brian Brown - thanks for the excellent tips. We are not going to pull the engine. The yard will cut the shaft and install all new parts including a split shaft to engine coupler which will make maintenance much easier in the future. By the way the price difference between the standard coupler and the split coupler is about $20. I would gladly pay an additional $20 for the boat for easier maintenance.

Dan - You may be correct on exercising the stuffing box nut, however I have never had a problem in the past with multiple boats. I am going to the boat Monday to see what the yard has discovered on the stuffing box. I will post what they find.

Thanks again for all the responses.

 

[dclagett]

Went over to the boat today and looked at the stuffing box with the yard mechanic. The threads look good, so it was not cross threaded. It is like the threads do not match, the box will not screw back together. In addition we found that the stuffing box was rubbing on the shaft and the cutlass bearing needs replacing, lots of play. The boat only has 300 hundred hours of run time.

All the new parts should be in this week and I am expecting the boat will be in the water early next week. Hopefully everything lines up. The yard will make final alignments in the water after the boat has had a day or so settle.

 

[Cutwater28GG]

thanks for the update!

 

[Salty7]

What year was Dream Chaser built and which engine do you have?

 

[BB marine]

Went over to the boat today and looked at the stuffing box with the yard mechanic. The threads look good, so it was not cross threaded. It is like the threads do not match, the box will not screw back together. In addition we found that the stuffing box was rubbing on the shaft and the cutlass bearing needs replacing, lots of play. The boat only has 300 hundred hours of run time.

All the new parts should be in this week and I am expecting the boat will be in the water early next week. Hopefully everything lines up. The yard will make final alignments in the water after the boat has had a day or so settle.

I have had no issues Yet! Over the past winter, because of a few post on TugNuts and commiserating with another Cutwater owner about the drive line assembly and packing issues I have looked into some tooling and components of the assembly. All the components come from Marine Hardware. The double ended taper shaft assembly is the an excellent choice for the drive train except for one big issue, Room.


("Marine Hardware,TM Inc. manufactures and assembles a variety of couplings to meet your needs. As always, if room allows, a double taper bronze coupling insures the tightest tolerances for better accuracies"). ( IF ROOM ALLOWS)

It is tight conditions in my C26, an other C28 owner, and dglagett's R-25 SC. The straight shaft coupling in the Ranger or Cutwater is probably the better choice. This would allow for easier removal ( still tight quarters) of the coupling, packing nut, and gland for inspection and repacking. The taper shaft coupling assembly used by Fluid Motion should have been matched up with the Gland style stuffing box (my opinion) instead of the nut gland style. This would give slightly better access and also a better choice for packing repair if the boat is in the water.( you can pull 2 rows out and replace in the water). If and when I have an issue with packing, coupling, cutlass or shaft I will also change shaft/coupling style, (straight) and packing to (Gland style).


The Alignment issue you have is strange. If the alignment was off enough to destroy your cutlass and rub on the gland housing I would speculate that you would have had vibration when running. At some point alignment has been done on your boat, during build , Pre-delivery inspection, and preventative maintenance. If you have no record of this ever being done, probably your issue. If alignment has been preformed and proven good then I would check all your engine mounts for tightness and damage, rubber mounts good, fasteners good, if all tight that means the engine didn't move. Next I would check what is left of your shaft for "straightness". Is it true? No, that's your issue. Yes, next I would inspect your coolant line going to the packing. This is what lubricates your cutlass bearing while under way. If you have limited flow or no flow this would damage your cutlass and cause misalignment. Where is the bearing worn 3 o'clock, 6 o'clock, 9 o'clock, Normal wear is 6 to 10 o'clock on a right hand prop. 300 hrs should show very little wear if any. I have 334 Hrs on my C26 when I pulled my prop this winter for inspection there was no noticeable wear or excessive play between shaft and bearing. Keep us posted on your findings.

 

[dclagett]

The engine alignment was off which I assume was the cause of the shaft rubbing on the stuffing box and the cutlass bearing failure. When the yard installed all the new parts they found that the engine needed to be raised in order to align it properly. There was not sufficient adjustment in the motor mounts to raise the engine to the level needed.

I am not that familiar with the motor mounts, but the yard said they looked fine. Could this problem have been there from when the boat was manufactured? Any ideas?

 

[BB marine]

Do you have the PDI sheet? The Dealer should have inspected and if needed aligned before delivery. If there is no record of that being done and you never aligned it. Maybe misaligned since new. An alignment that far off should have caused a vibration. I have corrected misalignment of .010 and eliminated a noticeable vibration. It seems that your alignment was much further out then .010.

If the stringer is solid and the mounts are in good usable condition. I would question the keel extension. Did it move or was it not installed properly causing misalignment ? The keel extension installed on Tugs and Cuts is the" shaft strut". When the keel extension is installed it sets the line that the shaft runs in. The factory has a specification where the keel extension is mounted to locate the shaft in the right position. Most boat manufactures have a engine position jig made up with a template for motor mount mounting holes and a saddle to hold the shaft. The jig is laid on the engine stinger, positions the strut, shaft and motor location all in a line. Once this is achieved the strut or keel extension is then fastened in this location. This installation allows for proper alignment of engine to shaft using the engine mount adjustment threads to lift or lower the engine for vertical misalignment and an oblong slot for horizontal side to side misalignment. If alignment is not achievable the set up was done improperly or something moved.

This is the jig that Fluid motion uses.


This jig looks like it has some room for error but I'm sure a lot of Keel extensions have been installed perfectly. Maybe your wasn't or it moved. You may have to use alignment shims to properly align the motor to shaft. I have used shims when aligning some of the old woodies. Good luck, big project on a boat with 300 hours.

 

[dclagett]

Brian,

Thanks for the excellent tutorial. The jig is quite interesting, but if aligned well I can see how it will do the job.

When you say that the keel extension may have moved, I assume you are talking about during manufacturing. The keel extension is glassed in and I don't see how it could currently move. There are no cracks around the keel so I assume it is currently in the same place when the boat was manufactured.

I went over to the boat today, talked to the mechanic and looked at the finished product. The alignment shims are actually 3/4 inch Delrin blocks under each motor mount. The mechanic told me the motor mounts originally were adjusted to the top of their travel and with the new parts installed the engine needed to be higher (almost 1/2 inch). The bocks allow the motor mounts to be adjusted closer to the middle of travel. By the way, the mechanic verified the engine mounts and stringer for the mounts are fine, so the engine was well connected to the boat.

The new design for the drive train has some improvements to help with maintainability in a very tight space. The shaft coupling is split with a straight shaft. They used a stuffing box without the extension for the water injection providing additional space between the stuffing box and the shaft coupling. The water injection is now aft of the stuffing box thru the fiberglass into the shaft tunnel.

I purchased the boat used with about 130 hours on the engine and do not have the PDI sheet. I will contact the dealer to see if they checked the alignment and a copy of the sheet. I felt very little to no vibration throughout the engine RPMs. I did not have the engine aligned in the 2.5 years I have owned the boat. The boat is a 2014 model put in service September 2014. I did however check that the engine was well attached to the stringers by having someone slowly cycle the shifter between forward and reverse at idle while I watched to see if the engine moved.

I can't wait to pick up the boat this week to see how it performs. Please don't ask me how much it cost to repack my stuffing box.

 

[BB marine]

The keel extension question, was there signs that it may have come loose or moved after the build. You answered that, No.
I think when you run the boat you are going to be pleasantly surprised in the difference. An alignment off, enough that the shaft rubbed on the stuffing box, and a worn cutlass bearing should have caused vibration.

 

[ALICE J]

If you raised the engine, you may want to check to see if any of the engine fashion shield plate bolts rub on the foil insulation. If so they will shortly poke a hole into the foam. I placed an aluminum plate in the offending area which also was next to the turbo that was scorching the foil. The plate sucked the foam up enough to allowance clearance. (screwed into the engine hatch. I have an R27 with a Yanmar, might not be the same clearance issue?)

 

[dclagett]

Well I picked up the boat yesterday and the good news is extremely smooth operation from idle to full throttle with the engine hatch not locked down. The bad news is the engine top plate contacts the engine hatch when the hatch is locked down or someone stands on the hatch. This creates a significant vibration and noise in the cockpit at idle. I did not operate the boat with the engine hatched locked, but I would assume this would not be pleasant with the engine in direct contact with hatch. The boat yard told me about the problem.

I plan to contact the factory to determine if they will help me with this problem since I believe the keel was misaligned when the boat was built.

 

[dclagett]

No help available, so this is all on my nickel.

The good news with over seven hours of operation in calm and rough conditions the boat operation is smooth as silk. The engine alignment problem I had did not create any significant vibration. I believe this lack of vibration is due to the very short prop shaft. The misalignment prematurely wore out the cutlass bearing and probably would have worn a hole in the stuffing box had it not been fixed. Engine alignment and cutlass bearing inspection will now be on my yearly check list.

I discussed the engine hatch problem with the yard and with some measurements it appears we will be able to remove part of the core under the hatch which will give the clearance necessary to stop contact with the engine. We will reinforce that area of the hatch with additional glass.

This has been quite an experience on a relatively new boat. This all started with me asking the yard to repack the stuffing box, a 45 minute job.

 

[BB marine]

Sounds like your boat is on the road to recovery. Its hard to believe this was found while doing a stuffing box packing replacement. I would contact Fluid motion outside of this forum. I believe they would help you out. It seems like a issue that may have been missed during the build. I'm sure they could explain the procedure they use for final alignment of the keel extension. Assuming they use Laser alignment its hard to believe it could be that far out.